The Science of Healthy Hair, Hair Loss and How to Regrow Hair

00:00:00.000 | Welcome to the Huberman Lab Podcast,

00:00:02.260 | where we discuss science and science-based tools

00:00:04.900 | for everyday life.

00:00:05.900 | I'm Andrew Huberman,

00:00:10.140 | and I'm a professor of neurobiology and ophthalmology

00:00:12.900 | at Stanford School of Medicine.

00:00:14.780 | Today, we are discussing hair.

00:00:16.900 | Hair is a topic that occupies the minds of many people.

00:00:20.580 | There are people that are losing their hair

00:00:22.860 | and want to halt or reverse that loss of hair.

00:00:26.540 | And today we will talk about all the ways

00:00:28.580 | that science has taught us we can slow

00:00:31.220 | or even reverse hair loss.

00:00:33.060 | I confess that researching today's topic

00:00:35.340 | was a particular joy for me,

00:00:37.240 | not because I'm obsessed with hair,

00:00:38.840 | mine or the hair of others,

00:00:40.800 | but because hair turns out to be fascinating

00:00:43.120 | from the perspective of cellular biology and stem cells,

00:00:47.140 | which is a topic that I've long been interested in

00:00:49.700 | and that for much of my career,

00:00:51.340 | I've focused on in the context of development.

00:00:54.200 | So when your brain and your nervous system develop,

00:00:56.820 | it develops from a small batch of cells

00:00:58.740 | that turns into many, many trillions of cells.

00:01:01.060 | And it does that by cell replication,

00:01:04.220 | something that we call the cell cycle.

00:01:06.060 | And we'll talk a little bit about this

00:01:07.460 | and so-called mitosis today.

00:01:09.380 | I promise not to get into too much detail,

00:01:11.660 | but what makes hair so very interesting

00:01:13.660 | from a biological standpoint is that every hair,

00:01:17.220 | every single individual strand of hair

00:01:20.140 | has its own little stem cell niche,

00:01:22.260 | meaning its own little pocket down there in the follicle

00:01:25.100 | in which specific stem cells give rise to those hairs

00:01:28.580 | for different durations of time, depending on the hair,

00:01:32.460 | where it is on your body, et cetera.

00:01:33.980 | So for instance, the hairs on your head

00:01:36.860 | will undergo ongoing growth for four to six

00:01:40.700 | or even eight years.

00:01:42.280 | So were you to not cut your hair,

00:01:44.660 | it would continue to grow.

00:01:46.000 | One single hair would continue to grow.

00:01:48.400 | I guess we could say all the hairs will continue to grow

00:01:51.020 | for up to eight years.

00:01:53.220 | That is very different from, for instance, your eyebrows,

00:01:56.920 | which have a much shorter period of hair growth

00:01:59.620 | lasting on the order of months.

00:02:01.240 | That's why you don't see people with eyebrows

00:02:03.540 | that extend down to their waist,

00:02:04.940 | but you can see people with hair on their head

00:02:07.500 | that extends down to their waist if they don't cut it.

00:02:10.880 | Now that discrepancy illustrates for us

00:02:13.200 | just how incredible hair follicles

00:02:15.900 | and the stem cells that reside within hairs are

00:02:18.340 | and their enormous potential to give rise

00:02:20.900 | to these things that we call hairs,

00:02:22.300 | which are simply proteins of varying length.

00:02:25.780 | So today we are going to address

00:02:27.220 | what determines the length of a hair

00:02:29.740 | or rather what determines how long a hair continues to grow

00:02:33.820 | before it ceases growing and eventually falls out.

00:02:36.620 | We're going to talk about what regulates those stem cells,

00:02:38.940 | what allows them to continue to produce hair

00:02:42.020 | or cease producing hair.

00:02:43.420 | And as we do that, you will learn all the biology

00:02:46.940 | in clear, simple terms, regardless of your background,

00:02:49.720 | that will really set the stage for understanding

00:02:51.660 | what we'll also talk about,

00:02:53.540 | which is how to slow hair loss or halt hair loss entirely,

00:02:58.540 | or even reverse hair loss.

00:03:00.980 | So we will talk about hormone-related hair loss

00:03:03.060 | in both men and women.

00:03:04.420 | We will talk about some of the mechanical

00:03:06.160 | and stress-related influences on hair loss.

00:03:08.220 | And we will talk about the chemical and mechanical approaches

00:03:12.180 | to halting and reversing hair loss,

00:03:13.860 | everything from minoxidil to dutasteride to ketoconazole

00:03:19.100 | to microneedling to thyroid, estrogen, IGF-1 pathways.

00:03:24.100 | Again, all made very clear,

00:03:25.860 | regardless of whether or not you have

00:03:27.860 | a background in biology or not.

00:03:30.440 | I will also dispel some of the common myths

00:03:32.300 | about balding and hair replacement.

00:03:34.340 | If you've heard, for instance,

00:03:35.660 | that you inherit your patterns of balding

00:03:37.860 | from your mother's father, that is not true.

00:03:41.980 | Although it is true that you do inherit certain genes

00:03:45.240 | that influence whether or not you have a predisposition

00:03:48.040 | to balding in particular parts of your head,

00:03:50.720 | and believe it or not, even particular parts of your body.

00:03:53.320 | But it is not the case that you can simply find a photo

00:03:56.620 | of your mother's father, say at age 50 or age 60 or 75,

00:04:01.380 | and determine whether or not you'll have

00:04:02.540 | the exact same pattern of hair loss.

00:04:04.260 | So that's a myth that I'd like to dispel right here and now,

00:04:07.380 | and I will dispel some of the other myths about hair loss,

00:04:10.460 | hair replacement, and hair regrowth as well.

00:04:13.540 | Before we begin, I'd like to emphasize that this podcast

00:04:16.140 | is separate from my teaching and research roles at Stanford.

00:04:18.760 | It is, however, part of my desire and effort

00:04:20.900 | to bring zero cost to consumer information about science

00:04:23.380 | and science-related tools to the general public.

00:04:25.760 | In keeping with that theme,

00:04:26.960 | I'd like to thank the sponsors of today's podcast.

00:04:29.560 | Our first sponsor is Helix Sleep.

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00:05:38.440 | Today's episode is also brought to us by HVMN Ketone IQ.

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00:05:46.620 | I want to be very clear that I, like most people,

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00:08:04.480 | Okay, let's talk about hair.

00:08:05.880 | And in researching this episode,

00:08:07.680 | by talking to experts in the biology of hair

00:08:10.760 | and the stem cells that exist in all of us

00:08:12.920 | that give rise to our hair growth

00:08:15.320 | and the pigmentation in our hair,

00:08:17.360 | and in talking to experts who understand how to halt

00:08:20.920 | and even reverse hair loss,

00:08:23.020 | that there is a tremendously interesting biology

00:08:25.760 | surrounding hair,

00:08:27.160 | but there's also an incredible psychology around hair.

00:08:31.080 | In fact, most people who experience even marginal hair loss

00:08:35.460 | undergo pretty severe anxiety.

00:08:37.540 | Now, I confess this is not something I can relate to.

00:08:39.760 | I am losing my hair in certain places.

00:08:42.140 | I'm 47 years old.

00:08:43.160 | I've got a couple of patches up front

00:08:44.860 | where there's very minimal hair.

00:08:46.560 | I think that, as we'll later learn in this episode,

00:08:49.720 | reflects a higher density of DHT,

00:08:52.020 | dihydrotestosterone receptors at that particular location

00:08:55.760 | as opposed to elsewhere on my scalp.

00:08:57.440 | But keeping my hair is not something

00:08:59.260 | that I've fretted about much of my life.

00:09:00.920 | And yet, as I was researching this episode,

00:09:02.840 | I remembered an anecdote from my childhood

00:09:05.320 | where my father told me,

00:09:08.440 | and I think it was because I was stressing about something.

00:09:11.640 | And I was trying to get to sleep.

00:09:13.120 | And he said, "Don't stress, calm down."

00:09:16.380 | And here's why.

00:09:17.760 | If you stress too much,

00:09:19.400 | it can actually make your hair fall out.

00:09:21.760 | In fact, I have a cousin who lay down one night stressed

00:09:25.540 | and woke up the next morning

00:09:26.820 | and all of his hair was on his pillow.

00:09:29.480 | And I'll never forget that story.

00:09:31.540 | I think he was trying to get me to stress less.

00:09:34.220 | I don't know if that story made me stress less or not.

00:09:37.660 | But in any event, I don't know that that story is true.

00:09:40.400 | I'm not going to challenge the authenticity of that story.

00:09:42.880 | I didn't have a chance to reach out to my father

00:09:44.960 | and ask him to verify or not.

00:09:47.420 | But as we'll soon learn,

00:09:48.760 | it is true that our psychological wellbeing

00:09:52.080 | can impact both the coloration, or lack thereof,

00:09:56.360 | and the growth rates of our hair.

00:09:58.160 | That's a real thing.

00:09:59.760 | And the reverse is also true,

00:10:01.540 | which is that as hair starts to thin or fall out

00:10:05.600 | or change color,

00:10:06.640 | many people experience intense anxiety or even depression.

00:10:10.240 | This was not something I was really aware of.

00:10:12.840 | And perhaps that's just

00:10:13.680 | because I've always kept my hair pretty short anyway.

00:10:15.500 | I always assumed that my hair started to really fall out

00:10:17.440 | or just shave my head.

00:10:18.480 | But that's me.

00:10:19.760 | And that's not most people out there.

00:10:21.740 | I think most people would loathe to lose their hair.

00:10:25.200 | And in fact, given the enormous number,

00:10:28.820 | probably up in the high billions of dollars and euros

00:10:33.000 | and other currency, of course,

00:10:35.200 | that people invest in trying to halt

00:10:37.640 | or reverse their hair loss,

00:10:38.640 | it's clear that hair is very, very important to people.

00:10:41.260 | What we know is that by age 50,

00:10:43.280 | approximately 50% of all men and women

00:10:46.780 | will have experienced significant enough hair loss

00:10:49.840 | that they start to notice it.

00:10:51.480 | And a large percentage, up to 85% of those people

00:10:55.420 | will experience some sort of anxiety

00:10:57.440 | that leads them to go out

00:10:59.760 | and try and either halt or reverse that hair loss.

00:11:02.640 | Now, why at age 50?

00:11:04.980 | Well, an important point arises from that,

00:11:06.820 | which is that the hair loss is not occurring

00:11:09.460 | between the 49th and 50th birthday.

00:11:11.700 | Hair loss is ongoing from about age 30 to age 50.

00:11:16.700 | It's only by age 50, however,

00:11:18.780 | that about 50% of people out there

00:11:21.540 | start to notice that hair loss.

00:11:23.540 | And this is typically because they'll be in a bathroom

00:11:26.600 | or looking in a mirror,

00:11:27.660 | and the lighting will be bright enough

00:11:29.680 | that it permeates the sort of outer boundary of their hair,

00:11:32.860 | and they'll notice that their hair is thinning

00:11:34.200 | in a particular location.

00:11:35.700 | That's usually how the sort of thing happens.

00:11:37.740 | So again, our psychological states can impact

00:11:41.460 | our patterns of hair growth or loss,

00:11:43.660 | and of course, patterns of hair growth,

00:11:45.980 | but more typically hair loss and hair graying

00:11:48.380 | can really impact psychological state.

00:11:50.020 | So this is a subject that people take intense interest in.

00:11:53.500 | And today we're going to talk about how hair normally grows,

00:11:56.820 | why it grows at the rate

00:11:58.940 | and for the duration that it happens to.

00:12:02.320 | And then as we talk about ways

00:12:03.620 | to intervene with that hair loss,

00:12:05.780 | those biological mechanisms will come up

00:12:07.640 | because they really provide a nice framework

00:12:10.000 | for explaining why certain treatments work more or less well

00:12:14.040 | or why certain treatments might have certain side effects

00:12:16.900 | or total lack of side effects.

00:12:18.560 | It will also highlight a really key theme

00:12:20.760 | that will come up several times in today's podcast,

00:12:23.060 | which is that there are both mechanical

00:12:25.380 | and chemical approaches to slowing and reversing hair loss.

00:12:30.380 | Mechanical approaches would be things

00:12:32.460 | as simple as massaging the scalp,

00:12:34.260 | but mechanical changes to the scalp

00:12:37.100 | can cause either hair loss or facilitate hair growth.

00:12:41.020 | This is why things like microneedling are so prominent

00:12:43.820 | in the context of trying to reverse hair loss.

00:12:46.400 | But again, there are also chemical approaches

00:12:48.580 | to trying to halt or reverse hair loss.

00:12:50.900 | And this relates to the fact

00:12:52.680 | that the hair growth itself is strongly regulated

00:12:55.940 | by hormones such as estrogen, thyroid hormone,

00:12:59.620 | insulin-like growth factor,

00:13:01.380 | and that other hormones, in particular the androgens,

00:13:04.780 | so things like testosterone,

00:13:06.500 | but mainly it's derivatives like dihydrotestosterone,

00:13:09.920 | are very much involved in setting the stage for hair growth

00:13:14.120 | by controlling how big or small that pool of stem cells

00:13:17.580 | that gives rise to hair growth is.

00:13:19.820 | So if any of the terms I just use are confusing to you,

00:13:22.380 | don't worry.

00:13:23.220 | I will make all of those very clear in a moment.

00:13:25.260 | It's actually all pretty straightforward and simple.

00:13:28.200 | And so I'd like to just start

00:13:29.840 | by talking about what hair is, how it grows,

00:13:33.780 | why it stops growing, and why hair normally falls out.

00:13:37.920 | Let's talk about the biology of hair.

00:13:39.620 | And in doing so, I also want to talk about stem cells.

00:13:42.440 | Now, keep in mind that when you hear the word stem cells,

00:13:44.720 | you, probably like most people,

00:13:46.680 | think about the sorts of cells

00:13:48.260 | that people are getting injected into their face

00:13:50.460 | to get rid of wrinkles or give them new skin

00:13:52.340 | or to give them more hair if it's injected in the scalp

00:13:55.020 | or into a joint to repair a joint or a muscle.

00:13:58.180 | Those stem cells are what we call exogenous stem cells,

00:14:02.180 | exogenous, meaning from outside the body.

00:14:05.480 | The stem cells that we're going to talk about today

00:14:07.860 | are so-called endogenous stem cells,

00:14:09.760 | cells that we all make that can give rise to other cells.

00:14:12.780 | And that's really the definition of a stem cell.

00:14:14.980 | Stem cells are present in all of us

00:14:16.880 | from the very beginning of life.

00:14:18.220 | So when sperm meets egg,

00:14:19.860 | that cell, which we think of as the egg,

00:14:22.980 | starts to duplicate.

00:14:24.260 | It incorporates the DNA from the sperm and the egg,

00:14:26.300 | of course, starts to duplicate.

00:14:28.340 | And then those cells give rise to more cells and more cells.

00:14:30.700 | And the ability of all those cells to replicate

00:14:32.660 | and create more cells are

00:14:33.500 | because those cells really are stem cells.

00:14:36.500 | Now, at some point, we are a completed body plan,

00:14:40.260 | as the biologists say.

00:14:42.040 | We end up with a brain and a spinal cord and limbs

00:14:44.860 | and fingers and livers and guts

00:14:47.740 | and all the things that we need

00:14:49.020 | in order to be a functioning human being,

00:14:51.260 | even though we're a baby at that time, we haven't grown up.

00:14:53.340 | We have all the bits that we're going to have

00:14:55.320 | for our entire life.

00:14:57.320 | At that point, many of the stem cell populations disappear.

00:15:01.660 | For instance, past puberty and probably earlier,

00:15:05.920 | you don't get many more new brain cells.

00:15:08.300 | You get a few, but you don't get many more new brain cells

00:15:11.100 | because the brain doesn't have many stem cell populations.

00:15:13.980 | Whereas other organs in your body

00:15:15.660 | maintain little pockets of stem cells

00:15:18.700 | or in some cases, many, many stem cells

00:15:20.900 | that can give rise to more and more of that tissue

00:15:23.280 | across the lifespan.

00:15:24.560 | And hair is one such tissue.

00:15:26.740 | So if we take a look at hair,

00:15:28.420 | what we find is that indeed,

00:15:30.340 | there are these things that we call hairs,

00:15:31.780 | but there are also stem cells.

00:15:33.740 | And those stem cells are actually what give rise

00:15:35.980 | to the hairs that we see on the head of our scalp

00:15:39.340 | or that we see on the surface of our body.

00:15:42.020 | So right off the bat,

00:15:43.820 | you should know that every single hair that you have

00:15:46.780 | is there because you have a stem cell population

00:15:49.940 | that is giving rise to that particular hair.

00:15:52.900 | So let's take a step back or rather, I should say,

00:15:55.700 | let's zoom in on one hair and the stem cell population

00:16:00.160 | that gives rise to that hair because in doing so,

00:16:03.000 | you're going to learn all the different components

00:16:05.300 | that you can tap into if your goal

00:16:07.100 | is to halt the loss of hairs

00:16:09.900 | or to replace hairs that have already been lost.

00:16:13.260 | Okay, so if we were to just zoom in at the level of one hair,

00:16:16.900 | what you would find is that that hair has

00:16:20.160 | what typically is called a hair root.

00:16:22.140 | So that's the portion below the skin.

00:16:23.900 | And when we say below the skin,

00:16:25.180 | it means that it dives down into a narrow trench,

00:16:29.640 | which is in the so-called epidermis,

00:16:31.340 | which is this outer layer of skin.

00:16:33.380 | It also has a shaft.

00:16:34.980 | The shaft is the part that grows out above the skin.

00:16:38.300 | So what you see on somebody's head

00:16:39.620 | or you see on their arm,

00:16:41.620 | or when you see an eyebrow, you're seeing the shaft

00:16:43.820 | of the hair, the root, of course, goes below the skin.

00:16:46.640 | What most people don't realize, however,

00:16:49.580 | is that down at the base of the root,

00:16:51.420 | there's actually a little cave, a little pocket.

00:16:54.420 | So if you were to look at this,

00:16:55.460 | it would look like a little bulb, a little round area

00:16:58.660 | with a bunch of stuff in it right below the root.

00:17:01.820 | And within that little cave, there are stem cells.

00:17:05.380 | There are populations of cells

00:17:07.540 | that have the ability to divide, right?

00:17:10.080 | We call this mitosis.

00:17:11.380 | It's a process by which cells can actually divide

00:17:13.780 | and take DNA with them and then give rise to other cells.

00:17:17.420 | We call those cells that divide and move out.

00:17:20.260 | We call those daughter cells.

00:17:21.920 | We call the cells that give rise to them progenitor cells,

00:17:24.660 | but they are effectively stem cells that give rise

00:17:27.320 | to these, what we call daughter cells.

00:17:29.760 | Those daughter cells then become the various types of cells

00:17:33.500 | that make up the hair.

00:17:35.220 | So when you see a hair, you're not seeing something

00:17:38.500 | that grows throughout the lifespan.

00:17:40.380 | You're seeing something that's going to be born down there

00:17:43.380 | in that little cave, then is going to grow.

00:17:46.260 | It's actually going to stack up on top of itself,

00:17:48.580 | and that's because hairs are made up

00:17:49.820 | of a protein called keratin.

00:17:51.420 | There are a bunch of different kinds of keratins,

00:17:52.900 | depending on what kind of hair you're looking at,

00:17:55.140 | but these are little proteins that stack up

00:17:57.140 | on top of one another, and they're structured in a way

00:17:59.480 | that makes them pretty darn durable.

00:18:01.620 | I mean, it's possible, of course, to pull a hair out,

00:18:04.420 | but if you've ever tried to tear a hair,

00:18:06.040 | in particular a thick hair, like one from the face

00:18:08.620 | or even one off the top of your head,

00:18:10.600 | it's actually a pretty tensile, strong little thing,

00:18:13.700 | and that's because keratins stack up on top of one another

00:18:16.540 | and bind to one another with a really strong bond.

00:18:19.980 | So what you end up with is a bunch of proteins stacked up

00:18:22.620 | on top of one another, and that's the actual hair, okay?

00:18:25.740 | So we've got the hair shaft, the hair root,

00:18:27.840 | and then we've got the stem cells down there in that pocket

00:18:30.020 | that give rise to the various cells

00:18:32.060 | that make up the actual hair.

00:18:34.020 | We also have down there in that little cave,

00:18:35.880 | which by the way is actually called the hair bulb,

00:18:37.980 | if you really want to know the technical name,

00:18:39.540 | 'cause it's shaped like a bulb.

00:18:41.360 | We have not just stem cells,

00:18:43.600 | but we have cells that give rise to the pigment of the hair

00:18:47.620 | that create what's called melanin.

00:18:49.720 | Now, some people have very blonde hair, very light hair.

00:18:52.340 | Some people have darker hair, but everybody,

00:18:55.580 | unless they have what's called the albino mutation,

00:18:58.700 | where the hairs are truly white, they lack all melanin,

00:19:02.060 | and it's a pretty rare condition, although it does happen.

00:19:04.360 | Most people have some degree of melanin in their hairs

00:19:07.740 | because there are little pockets of melanin-producing cells.

00:19:11.140 | Melanin's just a protein that essentially gets injected

00:19:14.420 | into the keratin, into the hair,

00:19:16.660 | and it gives it its darker color.

00:19:18.940 | Now, there are a couple other components about the hair

00:19:20.900 | that you need to know about,

00:19:22.380 | especially if you're interested in reversing hair loss

00:19:25.540 | or reversing graying of hair.

00:19:27.980 | One of those components is a little gland.

00:19:30.260 | So next to every hair root,

00:19:32.260 | within the dermal layer of the skin,

00:19:34.840 | so this is below the epidermis,

00:19:37.100 | there is a gland called the sebaceous gland,

00:19:39.980 | and the sebaceous gland makes oily stuff,

00:19:42.020 | and the oily stuff is called sebum.

00:19:44.220 | I know the name sort of evokes something kind of gross,

00:19:46.420 | but sebum is actually really cool and really important.

00:19:49.100 | The sebum gets injected, or seeps, rather,

00:19:53.140 | into the area right around the hair

00:19:55.660 | as the hair starts to approach the surface,

00:19:58.260 | where it goes from essentially root to shaft.

00:20:00.880 | And the sebum does two things.

00:20:03.620 | First of all, it forms a little bit of a seal

00:20:05.900 | right at the place where the hair exits the skin,

00:20:08.700 | and that seal is very important

00:20:10.500 | actually for waterproofing of your skin.

00:20:12.980 | So we don't often think of ourselves as waterproof

00:20:15.540 | because we are so accustomed to water

00:20:17.600 | just landing on our skin and rolling off,

00:20:20.180 | but that's because of some of the oily properties

00:20:22.280 | of our skin.

00:20:23.120 | Now, it's also true that our skin

00:20:24.180 | is pretty densely packed with cells,

00:20:26.300 | but in the absence of sebum,

00:20:28.440 | we would not be as waterproof as we are.

00:20:31.100 | Now, as I mentioned, sebum has two important properties.

00:20:33.500 | The other important property of sebum

00:20:35.440 | is that it actually is a strong antibacterial

00:20:38.820 | and antimicrobial.

00:20:41.320 | Most people don't realize this.

00:20:42.400 | The oils of your skin provide a lot of immune boundary

00:20:45.820 | so that things don't get into the hair root

00:20:48.060 | or the region around it and infect our skin.

00:20:50.880 | So sebum, while the name is sort of unattractive,

00:20:54.360 | to be honest, is actually performing some essential roles

00:20:57.260 | both for waterproofing and for our immune system function

00:21:00.220 | protecting us from various kinds of infection.

00:21:02.580 | We're going to return to sebum later.

00:21:05.020 | As it turns out, sebum is also very important

00:21:07.180 | as it relates to psoriasis

00:21:08.860 | and as it relates to some of the fungal components

00:21:11.440 | that can cause hair loss, okay?

00:21:13.500 | So just going to file that away.

00:21:15.460 | There's another important component

00:21:16.820 | of the region around hairs,

00:21:18.540 | which is the erector pili muscle.

00:21:21.020 | The erector pili muscle is a muscle that lies diagonally

00:21:24.420 | between that bulb portion of the hair

00:21:26.420 | or a little bit above it

00:21:27.540 | and goes up to the surface of the skin.

00:21:29.560 | The erector pili muscle is a muscle that contracts

00:21:34.140 | when we get cold or when we get scared.

00:21:37.380 | So if you've ever had goosebumps,

00:21:39.940 | that's because the erector pili muscle contracts

00:21:43.280 | pulling the skin at the surface down

00:21:45.500 | around the little hair follicles

00:21:47.660 | or at least where the hairs meet the surface of the skin.

00:21:50.700 | And so those little bumps are actually

00:21:52.460 | where little micro hairs reside

00:21:54.260 | and the dimples between them are the dimples that occur

00:21:58.120 | when this erector pili muscle pulls down.

00:22:00.900 | Now, why would this muscle exist?

00:22:02.380 | It has a couple of important functions.

00:22:04.140 | One of the functions is that when it pulls down,

00:22:07.040 | it causes, as the name suggests, the hairs to stand up,

00:22:11.660 | maybe not perfectly vertical, but they, when you hear,

00:22:13.960 | "Oh, I was so frightened, my hair stood up on end."

00:22:16.220 | And that's because the hairs become erect, they stand up.

00:22:20.140 | Now, why would this happen when we get cold?

00:22:22.100 | It happens because when the hairs stand up,

00:22:25.740 | air can be trapped between those hairs

00:22:27.780 | and can actually warm our body.

00:22:29.700 | This is not so much the case if you have very light hair

00:22:33.460 | on your skin, if you're a very hairy person,

00:22:35.460 | this is going to be a more robust aspect of your physiology.

00:22:38.180 | And yes, this is why dogs like huskies can go out in the snow

00:22:42.180 | and still remain warm.

00:22:43.460 | When they get cold, their hairs actually stand up a bit

00:22:46.540 | on end because of the contraction

00:22:47.900 | of these erector pili muscles trapping air in there,

00:22:50.960 | and then their body warms the hair, trapped beneath the hair

00:22:53.680 | and it's sort of like they've got a blanket on

00:22:55.500 | made by the interface between the hair,

00:22:58.700 | the air and their skin.

00:23:00.460 | So just to recap, all the components of hair

00:23:03.100 | and the different things around it that are going

00:23:04.940 | to be relevant for understanding how to replace hair

00:23:07.520 | that's lost, we have the hair itself,

00:23:10.480 | which has the shaft that sticks out over the skin,

00:23:14.820 | goes a little bit into the skin,

00:23:15.780 | but basically sticks out over the skin.

00:23:17.460 | We have the root portion, which goes down into the skin,

00:23:21.300 | it goes through the epidermis and into the dermis.

00:23:23.440 | Then we have this bulb-like region down at the bottom,

00:23:26.340 | down at the bottom of that bulb, we have stem cells

00:23:29.020 | that actually give rise to the actual hair,

00:23:30.940 | and we have pigmenting cells that pigment that hair.

00:23:34.640 | In addition, and this is very important,

00:23:37.400 | there are capillaries that go into that bulb region

00:23:42.220 | down at the bottom of the hair,

00:23:44.660 | and that can serve and support the stem cells,

00:23:47.620 | the melanin producing cells, which are called melanocytes.

00:23:51.140 | So the melanin producing cells and the stem cells

00:23:52.940 | get a lot of blood flow that allows them

00:23:55.160 | to keep providing new hair,

00:23:57.840 | or the proteins that make up hair,

00:24:00.180 | and the pigment that goes into those hairs,

00:24:02.700 | and those little capillaries deliver not just nutrients

00:24:07.160 | and things of that sort, but they also deliver oxygen,

00:24:09.820 | because it turns out that the whole process

00:24:11.340 | of growing more hair is a very active process.

00:24:14.420 | Now, as soon as you hear oxygen,

00:24:16.060 | and you hear that the growth is an active process,

00:24:18.660 | that should cue you to why so many of the stories

00:24:22.220 | around how to keep your hair and regrow hair

00:24:24.860 | involve statements like don't wear a hat,

00:24:27.960 | it'll make your hair fall out,

00:24:29.040 | or if you want your hair to grow back,

00:24:30.620 | you know, don't wear hats, or massage your scalp,

00:24:33.000 | or increase blood flow,

00:24:34.500 | or why some people will suggest

00:24:36.520 | that people take peppermint oil, for instance,

00:24:38.960 | or menthol-type oils of different kinds

00:24:41.420 | and massage them into the scalp,

00:24:43.040 | things that make the scalp tingle,

00:24:44.540 | or there will be light therapies designed to what?

00:24:47.800 | To increase blood flow to the scalp.

00:24:51.160 | The whole rationale there is that you're trying

00:24:53.320 | to increase blood flow to the stem cell

00:24:55.440 | and the melanocyte populations that support the hairs

00:24:58.400 | and that actually create the hairs.

00:25:00.120 | Now, whether or not those approaches work,

00:25:01.560 | we'll touch on a little bit later.

00:25:03.480 | I'll just give you a little bit of a hint right now,

00:25:05.340 | which is that while no single one of those approaches

00:25:09.220 | that I described is known to regrow hair

00:25:12.440 | in a very robust way,

00:25:14.360 | because of the requirement for oxygen and nutrients,

00:25:18.160 | and because it's such an active process

00:25:20.080 | for the stem cells and melanocytes

00:25:21.580 | to grow and darken the hairs that grow out of your skin,

00:25:25.500 | it is true that manipulations or treatments

00:25:29.540 | that increase blood flow to those regions

00:25:31.620 | can at least slow the loss of hair,

00:25:35.560 | or can even extend the duration

00:25:38.220 | over which hairs continue to grow.

00:25:40.880 | So if you've heard things like don't wear a hat

00:25:42.680 | if you want to maintain your hair,

00:25:43.980 | or massage your scalp if you want your hair to grow faster,

00:25:47.080 | in some sense, that's true,

00:25:48.860 | but none of those manipulations on their own

00:25:51.520 | is going to robustly enhance the rate of your hair growth.

00:25:55.940 | Those things are designed to be done

00:25:57.280 | in conjunction with some other treatments

00:25:59.740 | that have been shown in many, many clinical studies

00:26:02.880 | to increase the rate and duration of hair growth.

00:26:05.600 | So now you have in mind a picture of what's happening

00:26:07.760 | at the level of individual hairs.

00:26:09.400 | And if you're anything like me, you're probably thinking,

00:26:11.540 | wow, there's a lot going on down there,

00:26:14.040 | just below the surface of the skin, and indeed there is.

00:26:16.800 | But really the things to think about

00:26:18.020 | are that stem cell population

00:26:19.280 | that actually give rise to the hair proteins,

00:26:21.200 | so that actually create the hair,

00:26:23.660 | the melanocytes that darken that hair, they give it pigment,

00:26:27.200 | that sebaceous gland and the oil sebum

00:26:30.100 | that provides some important antimicrobial

00:26:33.120 | and other properties to that general region,

00:26:35.660 | and that erector pili muscle.

00:26:37.400 | That erector pili muscle, as I mentioned earlier,

00:26:40.160 | is important for creating goosebumps,

00:26:42.440 | and it's important for keeping huskies

00:26:44.380 | warm in cold environments,

00:26:45.640 | but it's doing some other really important things as well,

00:26:48.080 | and we'll talk about those as time goes on in this episode.

00:26:52.080 | Right now, what I want to do is just talk for a moment

00:26:55.360 | about how hairs actually grow

00:26:57.940 | and why they grow the way they do.

00:26:59.780 | This is extremely important

00:27:01.520 | toward understanding hair replacement and slowing hair loss.

00:27:05.980 | There are three basic phases of growth of a hair.

00:27:11.260 | The first phase is the phase in which the stem cells

00:27:14.560 | down in that bulb give rise to the cells

00:27:17.960 | that make up the proteins of the hair,

00:27:19.640 | so the actual growth of the hair,

00:27:21.480 | and keep in mind that the hair is actually growing

00:27:24.440 | from the bottom up.

00:27:26.620 | Now, you might think,

00:27:27.460 | "Of course it's growing from the bottom up."

00:27:28.440 | Everyone knows that, but a lot of people think

00:27:30.400 | that the hair starts growing right at the surface

00:27:32.120 | of the skin.

00:27:32.960 | That's not the way it works.

00:27:33.780 | The hair is actually growing from deep within the root

00:27:36.280 | and stacking up and then eventually extends out

00:27:39.960 | across the top of the skin.

00:27:41.360 | That growth phase is called the anagen phase, A-N-A-G-E-N.

00:27:48.060 | And this, for some people, will ring a bell

00:27:50.520 | because if you've ever been interested in weightlifting,

00:27:54.300 | or even if you're an endurance runner,

00:27:55.900 | you'll hear about things that are anabolic

00:27:58.260 | that promote growth, so ana of growth,

00:28:01.560 | or catabolic that promote breakdown.

00:28:04.940 | So the first phase of hair growth is called the anagen phase,

00:28:08.940 | and it's a period of varying duration

00:28:11.660 | depending on which hair and the body we're talking about.

00:28:15.140 | So the anagen or the growth phase for hairs on the head,

00:28:18.160 | as I mentioned earlier, is anywhere from two to eight years.

00:28:21.900 | For most people, it's going to be about six years.

00:28:24.040 | What this means is that if we were to just not cut our hair,

00:28:27.300 | just let our hair grow for two to eight years,

00:28:31.820 | that hair would eventually grow to a length

00:28:34.220 | that it was at its maximum and then would stop growing.

00:28:38.140 | So we can say that the anagen phase of hairs on the scalp

00:28:42.380 | is two to eight years, the duration of the growth phase.

00:28:46.300 | Contrast that, for instance,

00:28:48.240 | with the duration of the anagen phase

00:28:51.040 | for hairs of the eyebrows.

00:28:52.780 | The hairs of the eyebrows grow

00:28:55.300 | about 4.2 millimeters per month.

00:28:59.140 | Believe it or not, people have measured this sort of thing.

00:29:00.780 | Now, that's an average,

00:29:01.860 | so some people are going to have eyebrows

00:29:03.560 | that grow much longer per month.

00:29:06.560 | I'm somebody who, for instance,

00:29:08.940 | has mostly the same length eyebrow hairs,

00:29:11.740 | every once in a while, I get one of those eyebrow hairs

00:29:13.500 | that really seems to be heading off my head,

00:29:15.460 | it really wants out of there,

00:29:16.940 | and so it's much longer than the rest.

00:29:18.840 | What does that mean?

00:29:19.700 | Does it mean that it grew faster?

00:29:21.880 | Maybe, but chances are the stem cell population

00:29:26.760 | in that particular eyebrow follicle,

00:29:29.260 | for that one eyebrow hair,

00:29:32.220 | is longer than it is for the others.

00:29:34.940 | This is really important.

00:29:35.900 | I'm trying to illustrate two principles at once here.

00:29:38.420 | The first principle is that different hairs on your body,

00:29:41.860 | including the hairs on your scalp,

00:29:43.340 | have a growth phase of different duration.

00:29:45.300 | This is why the hairs on your head can grow very, very long

00:29:47.700 | 'cause they have a very long anagen or growth phase,

00:29:50.060 | and the hairs on your eyebrows will only grow

00:29:52.640 | for a few months before they actually fall out

00:29:55.740 | and then have to undergo replication of the stem cells

00:29:59.260 | to give you new eyebrow hair to then grow.

00:30:02.380 | What's important here is not just that there are differences

00:30:06.060 | in the duration of the growth phase,

00:30:08.200 | but rather that the rate of hair growth is not something

00:30:13.100 | that tends to differ within a given body region, right?

00:30:16.720 | You'll hear people say,

00:30:17.800 | "Oh, my hair grows really, really fast."

00:30:19.760 | Other people will say,

00:30:20.600 | "Oh, my hair grows really, really slowly."

00:30:23.180 | That is probably not the case.

00:30:25.160 | While there could be slight differences

00:30:26.380 | in the rate of growth,

00:30:27.500 | that is the addition of more keratin to the actual hairs,

00:30:31.700 | so creation of more hair more quickly,

00:30:34.420 | almost certainly what's happening

00:30:36.660 | is that the duration of the anagen phase in some people

00:30:40.180 | is just much longer than it is in other people,

00:30:43.040 | and we don't realize this,

00:30:44.640 | and we tend to think more in terms of how fast hair grows

00:30:47.380 | because if you were to just look at somebody's hair,

00:30:49.740 | you'd say, "Oh, they're all more or less the same length."

00:30:52.280 | I mean, some people's bangs are shorter than the back

00:30:54.060 | because they cut them,

00:30:54.900 | but if they were to just grow their hair,

00:30:56.160 | you'd say, "Oh, it's all more or less the same length,"

00:30:57.820 | but if we were to zoom in with a microscope,

00:31:00.080 | we would see that there are a lot of hairs down there

00:31:02.520 | in between the other hairs that are very, very short

00:31:05.340 | or even tiny, tiny, tiny,

00:31:06.660 | and those are coming in

00:31:07.660 | as the other ones are finishing their anagen phase, okay?

00:31:10.740 | So that's the anagen or growth phase.

00:31:12.860 | After the anagen phase comes the catagen phase.

00:31:17.080 | Again, this resembles the word catabolic

00:31:19.900 | or the breakdown phase.

00:31:21.180 | During the catagen phase,

00:31:23.300 | the hair is actually receding not from the top

00:31:28.060 | down to the skin surface and then into the root,

00:31:30.580 | but the other way.

00:31:31.620 | It's actually receding from that bulb region

00:31:34.460 | up toward the surface,

00:31:36.180 | and that catagen phase is going to also be

00:31:39.220 | of different duration depending on

00:31:41.300 | which area of the body you're in,

00:31:42.380 | and it will vary a little bit depending on who you are,

00:31:45.500 | meaning from person to person.

00:31:46.820 | We'll talk about the influences on the anagen

00:31:48.700 | and catagen phase in a moment.

00:31:50.440 | Why is it important that it actually recedes

00:31:52.420 | from the inside out?

00:31:53.860 | Well, that's important because as it does that,

00:31:56.980 | there's actually a change in that bulb region down below

00:32:00.940 | because normally there's an interface.

00:32:02.660 | There's a conversation that's occurring

00:32:04.740 | between the stem cell population,

00:32:06.140 | the melanocytes, and the hair itself,

00:32:07.740 | and they support each other.

00:32:09.180 | And remember there's blood vessels going into that area

00:32:11.100 | or rather capillaries that are feeding that area as well.

00:32:13.900 | After the catagen phase comes the telogen phase,

00:32:18.260 | which means rest.

00:32:19.740 | The telogen phase is a period in which no new hair proteins

00:32:23.760 | are being added by those stem cells.

00:32:25.460 | And during that telogen phase,

00:32:27.620 | that bulb down there at the bottom,

00:32:29.440 | instead of being nice and oval and really having

00:32:32.960 | a lot of space in it with all these different things

00:32:34.500 | like stem cells, starts to pinch off from the little tube

00:32:39.500 | that comes down from the surface of the skin

00:32:41.440 | that normally would have a hair in it,

00:32:43.020 | it starts to pinch off.

00:32:44.320 | And at some point, many hair follicles pinch off

00:32:46.680 | that bulb region and it recedes and dies.

00:32:49.760 | And when it recedes and dies,

00:32:51.480 | the stem cell population and the melanocytes go with it.

00:32:55.160 | In other words, there is no longer a population

00:32:57.560 | of stem cells to give rise to more hair

00:33:01.180 | after that telogen phase.

00:33:02.980 | And there's no longer melanocytes to pigment the hair.

00:33:05.640 | And in fact, the hair isn't there anymore,

00:33:07.220 | so there's no hair even to pigment after that telogen phase,

00:33:10.940 | unless it's a hair of a particular type,

00:33:14.640 | such as the hair on your scalp,

00:33:16.740 | which can then reenter the cell cycle

00:33:19.200 | and get back into an antigen phase

00:33:21.100 | and regrow more hair from stem cells.

00:33:23.940 | So there are three critical stages

00:33:26.140 | of the life cycle of a hair

00:33:28.180 | that are relevant to today's conversation.

00:33:30.300 | There's the antigen phase during which the hair grows.

00:33:32.920 | There's the catagen phase

00:33:34.180 | during which the hair actually starts to recede and die.

00:33:37.940 | The protein is actually disappearing from the bottom up.

00:33:41.500 | And then we have the telogen phase,

00:33:43.400 | which is the phase in which the stem cell population

00:33:45.740 | is what's called a semiquiescent, semiquiet,

00:33:48.880 | or completely quiescent, where it's not active at all.

00:33:52.820 | Those three phases make up the life cycle of a hair,

00:33:56.860 | keeping in mind that for some hairs,

00:33:59.160 | they can reenter the life cycle

00:34:01.440 | and go back into the antigen phase

00:34:03.220 | if there's stem cells there,

00:34:05.340 | and if there's oxygen there,

00:34:07.360 | and if there is sufficient blood support,

00:34:10.580 | and, and this is a very important and,

00:34:13.500 | if there are the appropriate hormonal signals

00:34:16.480 | to support growth,

00:34:17.860 | and there is a reduction or an absence

00:34:20.640 | in the hormone signals that actually trigger

00:34:23.500 | that telogen phase.

00:34:25.160 | I make this point now

00:34:26.340 | because much of the rest of today's discussion

00:34:28.500 | is going to focus on why particular hormones,

00:34:31.660 | such as dihydrotestosterone, cause hair loss,

00:34:35.740 | and why inhibiting things like dihydrotestosterone

00:34:38.640 | can support the preservation of hair that you have

00:34:41.620 | and the regrowth of hair.

00:34:43.100 | And to make a long story very short,

00:34:44.620 | and then we'll get into some additional details

00:34:46.260 | that are relevant

00:34:47.100 | and that I hope you'll stick around to listen to,

00:34:50.280 | dihydrotestosterone, which is the derivative of testosterone,

00:34:54.540 | causes changes in that bulb region

00:34:57.700 | where the stem cells reside.

00:34:59.420 | It shortens or halts the antigen phase of hair growth,

00:35:03.900 | and it extends and promotes the catagen and telogen phase.

00:35:08.900 | So when we hear that, oh, you know,

00:35:10.740 | dihydrotestosterone makes your hair fall out,

00:35:12.860 | or estrogen makes your hair grow,

00:35:14.660 | there are real chemical, or we should say biochemical,

00:35:18.060 | legitimate reasons as to why that is,

00:35:20.220 | but it all comes back to this three phases of hair growth,

00:35:23.720 | the antigen growth phase,

00:35:24.780 | the catagen catabolic or hair loss phase,

00:35:28.360 | and the telogen phase,

00:35:29.320 | which is a rest period in which the hairs

00:35:31.940 | can either come back if it reenters the antigen phase,

00:35:34.280 | or maybe it's over for good.

00:35:36.240 | Hormones are the accelerator and the brake

00:35:39.120 | on each one of those phases.

00:35:41.060 | I'd like to take a quick break

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00:36:55.520 | So now you have in mind the anatomy of the hair

00:36:58.680 | and the area from which it grows and the stem cells, et cetera.

00:37:02.120 | The fact that there's capillary innervation

00:37:03.920 | delivering oxygen and blood flow to the stem cells

00:37:07.560 | that give rise to the hair,

00:37:08.960 | and that there are these three critical phases

00:37:11.160 | of hair growth, antigen, catagen, and telogen.

00:37:14.780 | Now let's talk about the accelerators on hair growth

00:37:18.160 | and the breaks on hair growth.

00:37:20.500 | There are many accelerators on hair growth,

00:37:22.740 | but the first one that I really want to underscore

00:37:25.620 | is blood flow itself,

00:37:28.080 | which equates to the delivery of nutrients and oxygen.

00:37:31.900 | This is very important,

00:37:33.440 | and it explains a lot of the treatments

00:37:35.360 | for halting and reversing hair loss.

00:37:38.200 | For instance, one of the longest standing treatments

00:37:41.040 | for halting and reversing hair loss is so-called minoxidil.

00:37:45.040 | Minoxidil, sometimes also referred to

00:37:47.580 | by the brand name Rogaine,

00:37:49.560 | was actually a drug that was developed

00:37:51.460 | to treat hypertension.

00:37:53.040 | So this is a cardiac drug that lowers blood pressure,

00:37:56.500 | and it does that by causing vasodilation.

00:37:59.220 | It allows more blood flow,

00:38:01.140 | not just to the hairs on your scalp,

00:38:03.180 | but to hairs everywhere on your body.

00:38:05.120 | And indeed, most people don't realize this,

00:38:07.060 | but minoxidil won't just slow the loss of hair

00:38:10.640 | from your scalp.

00:38:11.860 | It is also effective at slowing the loss of hair

00:38:14.380 | elsewhere in your body.

00:38:15.460 | How does it do that?

00:38:17.120 | Well, you now know one of the major ways it does that.

00:38:20.140 | It does that by extending the anagen phase,

00:38:23.820 | how it basically makes that phase a bit longer.

00:38:27.180 | It doesn't make it much, much longer,

00:38:28.860 | which is why for most people

00:38:30.500 | who are losing their hair quickly

00:38:31.940 | or who have already lost their hair,

00:38:34.220 | minoxidil alone is not going to be a sufficient treatment.

00:38:37.260 | However, minoxidil has been shown to be effective

00:38:40.140 | at slowing rates of hair loss,

00:38:41.800 | and people that are starting to experience some hair loss

00:38:43.940 | all get into dosages and things of that sort

00:38:45.780 | a little bit later.

00:38:46.640 | But right now I just want to really focus on the logic

00:38:48.960 | of why people would take this drug,

00:38:51.160 | which is lowering hypertension at all

00:38:54.680 | as it relates to hair loss, right?

00:38:56.000 | That might seem like kind of crazy

00:38:57.500 | until you understand the anatomy and the growth of hairs,

00:39:00.180 | which you now do.

00:39:01.220 | So that's what minoxidil is doing.

00:39:02.740 | It's creating more blood flow to the hairs,

00:39:05.280 | which because minoxidil does have this positive effect,

00:39:09.520 | at least most people would like to slow their rates

00:39:11.620 | of hair loss on their scalp anyway,

00:39:14.080 | it tells you that blood flow and delivery of oxygen

00:39:17.940 | and other nutrients from the blood is pretty critical,

00:39:20.620 | if not very critical,

00:39:22.200 | for the support of the hair growth cycle itself.

00:39:25.980 | Now, again, we haven't talked at all

00:39:27.680 | about the sorts of chemicals

00:39:29.340 | or the signals within the body such as hormones

00:39:31.740 | that actually direct the growth of hairs.

00:39:33.500 | Here we're just talking about a mechanical change,

00:39:36.060 | allow more blood flow to the region

00:39:38.020 | and thereby extend the antigen phase,

00:39:39.900 | which is exactly what happens with minoxidil.

00:39:42.500 | Now, minoxidil does have other effects,

00:39:44.880 | and this is why dosing of minoxidil

00:39:46.540 | becomes a little bit complicated

00:39:48.660 | and can be a little bit tricky to troubleshoot.

00:39:51.260 | It can greatly lower blood pressure

00:39:53.500 | or lower blood pressure just a little bit,

00:39:55.280 | depending on how sensitive somebody is

00:39:57.060 | to that particular drug.

00:39:58.680 | So oftentimes physicians will start people

00:40:00.620 | on minoxidil dosages that are very low,

00:40:02.980 | ideally that would be the case,

00:40:04.260 | and then ratchet it up in order to figure out

00:40:07.220 | where the minimal effective dose

00:40:08.860 | or the kind of critical threshold is

00:40:10.300 | beyond which they start experiencing

00:40:12.200 | some pretty uncomfortable side effects,

00:40:14.340 | such as swelling of the ankles or headaches or dizziness.

00:40:18.380 | These things can happen with the use of Rogaine,

00:40:20.740 | AKA minoxidil.

00:40:22.420 | Now, minoxidil has also been associated

00:40:24.960 | with increases in the hormone prolactin.

00:40:27.980 | Prolactin is a hormone that's released from the pituitary.

00:40:31.540 | It is a hormone that acts also

00:40:34.200 | as a bit of a neurotransmitter like many hormones,

00:40:36.940 | and it tends to be antagonistic or an opposite to dopamine.

00:40:41.160 | So dopamine is a neurochemical,

00:40:43.540 | it's actually a neuromodulator,

00:40:45.000 | meaning it modulates the activity

00:40:46.500 | of a bunch of neural circuits in the brain.

00:40:47.940 | It also controls the release of various hormones

00:40:50.720 | in the body.

00:40:51.600 | Dopamine is almost always associated

00:40:54.260 | with states of motivation, pursuit, and drive.

00:40:56.940 | It has a little bit of a kind of feel-good element to it,

00:40:59.820 | which is why a lot of people think dopamine is associated

00:41:02.060 | with reward and pleasure,

00:41:03.260 | but it's really about energy, motivation, and drive.

00:41:06.860 | Dopamine and prolactin are, as I mentioned before,

00:41:09.560 | antagonistic to one another.

00:41:10.900 | They're in sort of a push-pull.

00:41:12.760 | So people who take minoxidil,

00:41:14.740 | especially if they're very sensitive to it

00:41:16.060 | or they take dosages that are too high,

00:41:18.340 | will experience increases in prolactin

00:41:20.820 | that in turn can cause things like reductions in libido,

00:41:25.620 | reductions in overall feelings of wellbeing, apathy.

00:41:29.220 | And in some cases where the elevations in prolactin

00:41:32.620 | are more extreme, they can experience, for instance,

00:41:35.820 | increase in male breast tissue, gynecomastia,

00:41:38.540 | or even small bits of milk let down, things of that sort.

00:41:42.400 | In women who take minoxidil,

00:41:44.460 | the side effects are much like the ones experienced in men.

00:41:47.860 | So there can be swelling, edema of the tissues,

00:41:51.100 | because if you get too much vasodilation

00:41:52.900 | and too much lowering of blood pressure, that's not good,

00:41:56.140 | headaches, dizziness, and so on.

00:41:57.780 | So dosing of minoxidil is really important.

00:42:00.460 | If somebody is going to use minoxidil

00:42:03.060 | in order to try and slow or reverse hair loss,

00:42:05.840 | and again, it mainly is going to be used

00:42:07.820 | to slow rates of hair loss,

00:42:09.120 | not to actually reverse hair loss,

00:42:11.020 | the really key thing is to get that dosage right.

00:42:13.140 | So the ranges of minoxidil that you'll see suggested

00:42:15.620 | and that people use out there are vast.

00:42:18.300 | And I should also mention that there are two major routes

00:42:21.260 | by which people get minoxidil to the hair follicle.

00:42:23.700 | One is to take it systemically as a pill,

00:42:25.780 | where it goes into the general circulation.

00:42:27.980 | The other is to take it topically as a cream.

00:42:30.940 | There are prescription and non-prescription forms

00:42:34.040 | of minoxidil, just to further complicate things.

00:42:36.460 | But the ranges of oral minoxidil that you'll see out there

00:42:39.980 | and that people take range anywhere from 0.25 milligrams

00:42:44.660 | all the way up to five milligrams per day.

00:42:47.760 | So that's an enormous range, it's like a 20-fold range.

00:42:50.660 | The topical minoxidil is also found

00:42:55.000 | in various concentrations.

00:42:56.160 | The typical concentration is going to be a 5% concentration

00:42:59.800 | that people will use once per day.

00:43:01.680 | Topical treatment with minoxidil at 5% concentration

00:43:05.720 | is thought to just stay at the scalp,

00:43:08.380 | but we now know that it can go systemically.

00:43:11.360 | It can get into the general bloodstream.

00:43:13.140 | Why that issue make complete sense to you?

00:43:14.700 | Because when you put something on your scalp,

00:43:16.440 | I've already told you that these little pits,

00:43:19.120 | these little tubes that go down to those bulb regions

00:43:21.980 | below the skin that have direct access to the blood supply.

00:43:26.300 | So when you massage something into your scalp,

00:43:28.440 | it not only has the opportunity

00:43:30.040 | to get into your general circulation, it often does,

00:43:33.060 | especially if it's something that's very water-soluble,

00:43:37.160 | and that way can get into the capillaries

00:43:38.960 | and into the general bloodstream.

00:43:40.640 | Although topical treatments,

00:43:42.900 | of which we're going to discuss a number of them today,

00:43:45.260 | don't tend to get into the general circulation

00:43:47.880 | as robustly as taking something by way of pill or capsule.

00:43:52.280 | Okay, so minoxidil works by way of increasing blood flow

00:43:55.600 | to the stem cell niche below the hair.

00:43:58.520 | The dosage ranges of the oral minoxidil are tremendous,

00:44:02.920 | 0.25 milligrams all the way up to five milligrams

00:44:05.360 | once per day.

00:44:06.400 | The dosage range of the topical solutions

00:44:09.160 | tends to be a little bit more confined.

00:44:10.880 | Typically it's a 5% solution,

00:44:12.840 | and it's recommended that people use it one time daily,

00:44:16.200 | maybe twice daily.

00:44:17.600 | It's also important, by the way,

00:44:19.360 | if you're going to take this route,

00:44:20.960 | that you actually leave that solution on the scalp

00:44:23.240 | for three to five minutes.

00:44:24.360 | This is important and should make complete sense

00:44:26.680 | as to why it's important.

00:44:27.520 | You can't just rub the stuff into your head

00:44:29.160 | and then rinse it off and expect it to be absorbed.

00:44:31.180 | It actually needs to seep down into those hair follicles

00:44:34.600 | and access the niche.

00:44:36.320 | How do people arrive at the correct dosage for minoxidil?

00:44:41.080 | Well, for better or for worse, really.

00:44:43.880 | In some cases, it's accomplished by finding out

00:44:46.920 | that you have an unwanted side effect,

00:44:49.360 | like dizziness or swelling of your ankles or edema,

00:44:53.400 | or I would hope this wouldn't be the case,

00:44:55.720 | but something that suggests there's hyperprolactinemia.

00:44:59.640 | You could get a blood test to measure your prolactin,

00:45:01.800 | or you perhaps notice a drop in libido or some lethargy,

00:45:06.000 | these sorts of things that are common

00:45:07.820 | to reduce levels of dopamine, increase levels of prolactin.

00:45:11.200 | I would hope that if people are working with a physician

00:45:13.240 | or if they're not in taking minoxidil,

00:45:15.460 | that they would start with the lowest possible dose.

00:45:19.240 | So for oral minoxidil, that would be 0.25 milligrams

00:45:22.680 | and then increase it as needed

00:45:24.640 | rather than jumping in right at five milligrams,

00:45:27.040 | because some of those side effects,

00:45:28.440 | in particular the fluid retention and the hyperprolactinemia

00:45:31.560 | can be pretty uncomfortable

00:45:32.920 | and can disrupt a lot of aspects of life

00:45:35.000 | that most all of us consider desirable.

00:45:37.320 | Okay, so we're really focusing right now

00:45:38.940 | on treatments that relate to the critical requirement

00:45:42.400 | for hair stem cells to receive blood flow

00:45:45.760 | in order to receive oxygen and nutrients

00:45:48.340 | to get the hair to grow.

00:45:49.760 | And that's really what minoxidil is about.

00:45:52.520 | It's also what all of those anecdotes you hear

00:45:56.160 | are all about like massaging the scalp

00:45:59.120 | or putting red light on the scalp.

00:46:01.400 | Although red light might do some other things,

00:46:03.160 | in general heating or lighting of the scalp

00:46:05.680 | or massaging of the scalp is really designed

00:46:08.240 | to increase blood flow to the scalp.

00:46:10.480 | Now, the reason minoxidil works at all

00:46:12.900 | is because it is going to increase blood flow

00:46:15.920 | around the clock.

00:46:16.820 | And that's because people are taking it topically

00:46:19.060 | and it's seeping into the general circulation

00:46:21.040 | or at least it's staying somewhat restricted

00:46:23.520 | to the hair cell niche or they're taking it orally

00:46:26.140 | and it makes it to that hair cell niche below the follicle.

00:46:30.180 | When we massage our scalp, however,

00:46:33.720 | that's a transient thing.

00:46:35.120 | I can massage my scalp right now.

00:46:36.540 | I'm no doubt increasing blood flow to certain areas.

00:46:39.960 | I'm probably decreasing blood flow to the areas

00:46:41.620 | I'm pushing down on, but it's all temporary.

00:46:43.800 | I don't know many people that can massage their scalp enough

00:46:47.000 | during the day or long enough during the day, rather,

00:46:49.440 | that it would sufficiently increase blood flow.

00:46:52.400 | With that said, it is clear that increasing blood flow

00:46:54.800 | to the scalp by way of reducing hypertension,

00:46:58.040 | which is effectively accomplished by broadening,

00:47:01.600 | by expanding the blood vessels and capillaries,

00:47:05.200 | is an effective way to at least hold on

00:47:08.040 | to the hair that you have.

00:47:09.800 | Is it going to completely halt hair loss?

00:47:12.200 | If you have a strong genetic bias towards hair loss, no.

00:47:15.080 | Is it going to reverse hair loss?

00:47:16.800 | Very unlikely that it will,

00:47:18.260 | but it can slow hair loss

00:47:19.840 | or even maintain the hair that you have.

00:47:22.160 | So if we were to take a step back and ask ourselves

00:47:25.080 | what other sorts of drug treatments are out there

00:47:28.320 | besides minoxidil that increase blood flow

00:47:30.900 | and that might increase the rates of hair growth

00:47:34.040 | or more likely increase maintenance of hair

00:47:36.480 | that one already has by increasing blood flow to the niche.

00:47:39.700 | And nowadays, there are more and more doctors

00:47:42.120 | who are familiar with this requirement for blood flow,

00:47:45.200 | understand the mechanisms by which minoxidil works,

00:47:47.760 | and understand the vast desire out there

00:47:49.620 | for people to hold on to the hair they have and regrow hair.

00:47:52.080 | And they're prescribing things like low dose tadalafil.

00:47:56.080 | So 2.5 milligram to five milligram tadalafil.

00:47:59.900 | Tadalafil was initially discovered

00:48:01.960 | as a drug to treat prostate health.

00:48:05.280 | It was a drug that we now know

00:48:07.240 | can increase blood flow to the prostate

00:48:09.020 | and thereby offset some of the issues

00:48:11.560 | associated with an aging prostate.

00:48:14.060 | Higher doses of tadalafil, sometimes also referred to

00:48:18.560 | by its brand name, which is Cialis,

00:48:20.320 | are used to treat erectile dysfunction,

00:48:22.400 | but at the dosages that are used

00:48:23.740 | to increase blood flow to the prostate

00:48:25.720 | and that now a number of doctors

00:48:27.660 | are using to increase blood flow, not just to the prostate,

00:48:30.320 | but to all regions of the body, including the scalp,

00:48:34.020 | such as 2.5 to five milligrams tadalafil.

00:48:37.600 | So this is something that I think deserves attention

00:48:40.400 | because it falls under the umbrella

00:48:42.100 | of increasing blood flow to the hair stem cell niche

00:48:45.560 | in order to maintain hair.

00:48:47.700 | It is not something that most doctors

00:48:50.120 | are going to be familiar with as the way to reverse hair loss

00:48:53.840 | because it won't do that.

00:48:55.420 | But the use of low dose tadalafil to slow rates of hair loss

00:48:58.800 | is very much in a logical mechanistic sense,

00:49:03.280 | exactly the same as the logic of using minoxidil

00:49:05.900 | to slow rates of hair loss.

00:49:07.280 | It's all about increasing blood flow

00:49:09.360 | to support the stem cell niche below the hair follicle.

00:49:12.160 | The critical requirement for blood flow, oxygen,

00:49:15.280 | and nutrients to the stem cell niche

00:49:17.040 | is also why you hear a lot nowadays

00:49:19.300 | about the use of PRP, platelet-rich plasma,

00:49:23.340 | for trying to offset hair loss or even reverse hair loss.

00:49:27.480 | We're going to do an entire episode about PRP.

00:49:30.260 | It is pretty controversial in certain circles

00:49:32.580 | and well-accepted in other circles.

00:49:34.800 | A couple of key things to understand about PRP.

00:49:36.920 | First of all, it is being used in multiple tissues

00:49:40.320 | for different purposes in different clinics.

00:49:42.640 | So for instance, board-certified physicians

00:49:45.640 | in the United States, Canada, and Europe

00:49:47.720 | are doing PRP injections into ovaries

00:49:51.000 | to try and expand the number of healthy follicles and eggs

00:49:55.440 | so that people can conceive later in life,

00:49:58.120 | or even earlier in life if they don't have any follicles.

00:50:00.360 | People are getting PRP injections into their joints

00:50:02.960 | in order to try and support joint health.

00:50:05.640 | People are getting PRP injections

00:50:07.120 | into just about every tissue you can think of.

00:50:10.120 | However, PRP, despite what you may have heard,

00:50:13.840 | is not stem cells.

00:50:15.340 | Somebody tells you they're injecting stem cells.

00:50:16.940 | They're either outside the US, Canada, or Northern Europe,

00:50:20.000 | or they're injecting something else.

00:50:21.720 | So you want to really look into that.

00:50:24.100 | The safety issues there are the subject

00:50:28.200 | totally deserving of an entire episode.

00:50:29.920 | I'm not necessarily opposed to the future of stem cells

00:50:33.480 | as a treatment, but keep in mind

00:50:34.960 | that stem cells are cells that can give rise

00:50:36.480 | to lots of other cell types,

00:50:37.640 | and they are cells that divide and replicate,

00:50:40.540 | and there's a name for that when it happens

00:50:42.480 | in the adult body when you don't want that,

00:50:44.320 | and that's called cancer.

00:50:45.840 | Tumors are overproduction of cells from stem cells

00:50:49.280 | when those stem cells ordinarily should be quiescent, okay?

00:50:52.560 | So keep in mind the difference between stem cells and PRP.

00:50:55.040 | PRP, platelet-rich plasma, again, is legal in the US

00:50:59.360 | and many other places

00:51:00.720 | because it involves drawing somebody's blood,

00:51:03.120 | spinning it down at a particular speed,

00:51:05.720 | which separates out different components within the blood,

00:51:08.620 | then taking the platelets and re-injecting those

00:51:12.280 | in a solution back into the person's body.

00:51:15.680 | So platelet-rich plasma, or PRP,

00:51:18.680 | is platelet-enriched plasma from that person.

00:51:22.020 | But the basis of PRP is really to encourage

00:51:24.840 | nutrient delivery to a particular region in the body

00:51:27.880 | using somebody's own platelets

00:51:29.980 | because those platelets are enriched for various nutrients.

00:51:32.400 | So people are getting PRP injections into their scalp.

00:51:36.560 | Those are not stem cell injections.

00:51:37.960 | Those are PRP injections into the scalp

00:51:40.560 | with some moderate success.

00:51:42.660 | These are very expensive treatments.

00:51:44.400 | They tend to be transiently successful.

00:51:47.160 | I'm sure there are people out there who are going to say,

00:51:48.800 | "PRP worked fabulously well for me."

00:51:51.120 | That might be the case.

00:51:52.240 | I'm not going to dispute that, and I'm happy for you,

00:51:54.620 | although there are not sufficient clinical data

00:51:57.480 | to suggest PRP as a treatment right now,

00:51:59.360 | especially given the cost.

00:52:00.480 | Many thousands of dollars, many, many treatments.

00:52:03.140 | It's also the case that the PRP injections,

00:52:07.120 | when they work, might work for reasons

00:52:09.760 | independent of the platelets.

00:52:12.120 | What do I mean by that?

00:52:12.940 | Well, soon we're going to talk about

00:52:14.600 | a different type of treatment,

00:52:15.800 | which is a mechanical manipulation of the hair follicle,

00:52:19.560 | typically on the scalp,

00:52:20.380 | 'cause that's typically where people want to regrow hair.

00:52:22.080 | I don't know many people who are trying to maintain

00:52:24.280 | or accelerate or regrow their back hair, for instance.

00:52:28.040 | They might be out there,

00:52:29.040 | but I don't think there are a lot of them,

00:52:30.440 | or their leg hair, for that matter.

00:52:33.400 | Almost always, it's going to be scalp hair.

00:52:35.180 | And one way that people are doing that

00:52:37.000 | is through mechanical stimulation of the hair follicle

00:52:40.520 | and the stem cell niche using what's called microneedling.

00:52:43.320 | Microneedling, as the name suggests,

00:52:45.320 | is taking a bunch of little needles,

00:52:46.800 | either in a little stamp, so a little square,

00:52:49.680 | or nowadays, typically it's a roller,

00:52:52.000 | so it looks like a paint roller,

00:52:53.720 | except it's got tons of little needles in rows

00:52:57.400 | all over that roller.

00:52:58.440 | Those needles range in length from half a millimeter

00:53:01.880 | to 2.5 millimeters, okay, millimeters.

00:53:06.240 | And one rolls that over the scalp,

00:53:08.260 | and if you're thinking, "Ouch, that probably hurts,"

00:53:10.360 | indeed, it can hurt a little bit or a lot,

00:53:12.560 | depending on the thickness and the length of those needles.

00:53:17.160 | Microneedling has been shown to do two things.

00:53:19.920 | It has been shown to reactivate

00:53:22.760 | semiquiescent populations of stem cells

00:53:25.440 | that are in that telogen phase,

00:53:26.640 | putting them back in antigen phase,

00:53:28.400 | and thereby stimulate more hair growth.

00:53:30.660 | It has also, and this is, I think,

00:53:32.280 | the best use of microneedling,

00:53:33.960 | it has also been shown to be a very effective augment

00:53:37.320 | for some of the hormone-based hair regrowth tools

00:53:41.740 | and pharmacology that we're going to talk about

00:53:43.760 | in a few minutes.

00:53:44.720 | So microneedling and PRP have something very critical

00:53:47.340 | and common, which is the needle,

00:53:49.680 | the actual injection into the skin.

00:53:51.680 | And for those of you that are hearing this and thinking,

00:53:53.320 | "Why would disrupting the skin with needles

00:53:56.540 | actually support hair growth or regrowth?

00:53:59.880 | Wouldn't that just damage the follicle?"

00:54:02.040 | Well, this gets into some of the, I think, interesting,

00:54:05.340 | if not fascinating aspects of our biology,

00:54:08.180 | which is that all of the cells in our body

00:54:10.360 | really can respond to both chemical and mechanical cues.

00:54:14.400 | And when we hear needle injected in the skin,

00:54:16.960 | we think, "Ah, that must just be damaging everything,

00:54:19.800 | causing all sorts of inflammation."

00:54:21.700 | But it turns out that low levels of inflammation

00:54:24.300 | caused by things like microneedling or PRP injections,

00:54:27.500 | or even the introduction of any kind of fluid, right?

00:54:31.340 | For instance, saline fluid injected into a region

00:54:34.040 | can cause changes in the cells in that region,

00:54:37.220 | causing, for instance, stem cell populations

00:54:39.760 | that were waning to reactivate again,

00:54:42.900 | causing telogen phase follicles that have melanocytes

00:54:47.420 | and stem cells that are dying off, but not completely gone,

00:54:50.440 | to reenter the cell cycle.

00:54:53.120 | So microneedling procedures, PRP injections,

00:54:56.620 | things like minoxidil, they all kind of center

00:54:59.240 | around this same general theme of increasing blood flow,

00:55:02.900 | increasing oxygen, delivery of nutrients,

00:55:05.180 | or in the case of microneedling,

00:55:07.840 | increasing inflammation just enough at that local site

00:55:11.900 | that certain cascades of biological function

00:55:15.160 | that relate to proliferation of stem cells

00:55:18.140 | or maintenance of stem cell populations are kicked off.

00:55:21.100 | It's sort of like reminding the cells in that area

00:55:23.400 | that they need to stay alive

00:55:24.580 | in order to replenish whatever is lost.

00:55:27.120 | So sometimes a wound can actually induce some healing,

00:55:30.360 | although I do want to point out

00:55:32.600 | that the micro part of microneedling is absolutely key.

00:55:36.140 | And this should be obvious to you

00:55:37.480 | when you think about scars.

00:55:39.920 | I don't know about you,

00:55:40.760 | but I've never seen a scar with hair growing out of it.

00:55:43.980 | Or if there was, it was probably like one hair.

00:55:45.960 | But if you've ever seen a scar,

00:55:47.920 | someone had their appendix out

00:55:49.240 | or someone had a brain surgery,

00:55:51.000 | you see that scar because there is no hair growing out of it.

00:55:54.260 | So the micro portion of microneedling

00:55:57.580 | is extremely important.

00:55:58.580 | We are not talking about causing significant damage

00:56:02.180 | to a tissue in order to activate that stem cell population.

00:56:05.060 | We're talking about causing micro damage

00:56:07.100 | and micro levels of inflammation to stimulate growth.

00:56:10.680 | For those of you that are interested in using microneedling

00:56:13.620 | or microneedling in combination with chemical treatments

00:56:16.700 | like minoxidil or some of the other treatments

00:56:18.400 | we'll talk about in a little bit,

00:56:19.380 | like finasteride and caffeine.

00:56:21.800 | Yes, believe it or not,

00:56:22.760 | caffeine is being used to regrow hair.

00:56:24.680 | Very interesting, get into that in a moment.

00:56:27.060 | But if you're interested in using microneedling alone

00:56:29.280 | or in combination with some of these other treatments,

00:56:31.780 | there's a wonderful review

00:56:32.760 | that was just published this last year.

00:56:34.680 | Wonderful because it's very comprehensive.

00:56:37.140 | Not so wonderful, not to the fault of the authors

00:56:39.940 | because most of the studies out there on microneedling

00:56:43.500 | are not superb.

00:56:44.820 | There are ways of gauging the strength of a study,

00:56:47.300 | mainly related to their duration,

00:56:49.500 | whether or not there were control groups, et cetera.

00:56:51.740 | But the review itself is excellent.

00:56:53.580 | The title of the review is "Microneedling and its Use

00:56:56.260 | in Hair Loss Disorders," a systematic review.

00:56:58.700 | We will provide a link to this in the show note captions.

00:57:01.300 | And this review did a very good job

00:57:03.600 | of highlighting both the strengths and drawbacks

00:57:05.760 | of the various studies looking at microneedling.

00:57:08.060 | It also explored the use of microneedling

00:57:10.260 | in both men and women and of various ages.

00:57:14.180 | And it does appear to be the case

00:57:15.700 | that microneedling shows some positive benefit

00:57:18.200 | in both men and women, regardless of age,

00:57:20.300 | especially when used in combination

00:57:22.800 | with the various other treatments that we're talking about.

00:57:25.220 | I was also able to glean from this review

00:57:26.960 | and some of the papers described within it

00:57:29.420 | that needle lengths of about one millimeter to 2.5 millimeters

00:57:33.540 | seem to be more effective than shorter needle lengths.

00:57:37.460 | So if you're scared of the needles and the needle lengths,

00:57:40.620 | keep in mind that done properly,

00:57:42.200 | microneedling shouldn't be too painful.

00:57:44.460 | Some people experience a little bit more pain than others,

00:57:46.660 | but it's not considered a very painful procedure.

00:57:49.320 | It is, however, a procedure

00:57:50.720 | that can cause some bleeding of the scalp

00:57:53.260 | and that bleeding of the scalp can be very apparent,

00:57:56.000 | especially if it's in the front of the head

00:57:57.780 | as opposed to in the top of the head and hidden by some hair

00:58:00.180 | or if you're already quite bald in a given region.

00:58:04.300 | So keep that in mind.

00:58:05.940 | I suppose one could wear a hat or a wig

00:58:07.500 | or something of that sort

00:58:08.320 | if they were really self-conscious about it.

00:58:09.980 | But the microneedling itself is causing a physical disruption

00:58:14.220 | to the scalp, some degree of bleeding, inflammation,

00:58:17.140 | and again, all of that is part of the process

00:58:19.660 | by which microneedling can actually improve hair growth.

00:58:22.820 | And of course, there's healing that occurs

00:58:24.700 | of the bleeding and the damage to the follicle.

00:58:26.860 | This is a transient thing,

00:58:28.260 | but understanding the cosmetic implications

00:58:30.460 | in the short term as well as in the long term

00:58:32.740 | is certainly worth knowing.

00:58:34.320 | One thing that's very clear

00:58:35.300 | is that the combination of microneedling

00:58:36.900 | and minoxidil treatment together is far more effective

00:58:40.240 | than either of those treatments alone.

00:58:42.500 | In addition, the combination of microneedling and minoxidil

00:58:46.420 | has been shown to be effective

00:58:47.700 | in recovering what are called dead zones.

00:58:49.540 | So these are regions of the scalp

00:58:51.420 | that are either completely bald or mostly bald

00:58:54.000 | for which there is essentially no stem cell population there

00:58:58.860 | and the combination of minoxidil plus microneedling

00:59:02.140 | is somehow able to recover those stem cell populations

00:59:04.740 | and allow new hair to grow.

00:59:06.160 | Although the growth of that hair in those dead zone regions

00:59:09.260 | can take a very long time, 30 to even 50 weeks.

00:59:13.160 | Neither minoxidil treatment alone nor microneedling alone

00:59:16.860 | has been shown to be effective

00:59:18.140 | in recovering these so-called dead zones

00:59:20.140 | when those treatments are done separately.

00:59:22.440 | So this, I would say, is a strong reason

00:59:24.580 | to consider combining microneedling and minoxidil

00:59:27.760 | as opposed to just doing minoxidil or just microneedling.

00:59:31.100 | I should also mention that minoxidil treatment,

00:59:34.100 | if you pursue it, is likely something

00:59:36.120 | that you are going to have to do for the rest of your life

00:59:38.840 | if you want to hold on to the hair growth

00:59:41.060 | that you obtain with minoxidil,

00:59:43.100 | or if you want to maintain the hair

00:59:45.600 | that you are already maintaining with minoxidil.

00:59:48.280 | Some people have been successful in taking minoxidil,

00:59:51.720 | maintaining some hair growth

00:59:52.840 | or even stimulating some hair growth

00:59:54.340 | and then coming off minoxidil,

00:59:55.700 | but most everyone who goes on minoxidil

00:59:58.000 | has to stay on minoxidil

00:59:59.560 | because when they cease taking minoxidil,

01:00:01.700 | even if they're doing other treatments,

01:00:03.420 | they lose the hair that they gained with minoxidil.

01:00:06.640 | So that is an important consideration.

01:00:08.620 | The decision to go on minoxidil

01:00:09.960 | is likely a decision to be on minoxidil

01:00:12.120 | for the rest of your life.

01:00:13.580 | I'd like to just take a brief break

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01:00:28.140 | Now, salt, magnesium, and potassium

01:00:30.320 | are critical to the function of all the cells in your body,

01:00:32.820 | in particular, to the function of your nerve cells,

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01:00:36.680 | And we now know that even slight reductions

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01:00:55.280 | I typically drink Element first thing in the morning

01:00:57.320 | when I wake up in order to hydrate my body

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01:01:25.780 | So as you're probably starting to realize,

01:01:27.620 | there's a relationship between mechanical stimulation

01:01:30.160 | of the follicle and blood flow,

01:01:32.120 | both of which turn out to be critical for maintaining hair

01:01:35.200 | and for stimulating hair growth.

01:01:37.580 | Not surprisingly then,

01:01:38.880 | an increasingly common treatment for hair loss is Botox.

01:01:43.060 | Botox is the brand name for what is otherwise known

01:01:46.080 | as botulinum neurotoxin.

01:01:48.520 | What is botulinum neurotoxin?

01:01:50.500 | Well, botulinum neurotoxin,

01:01:51.940 | sometimes just called botulinum for short,

01:01:54.200 | is a toxin that's a bacterial toxin

01:01:57.160 | that serves to cut the protein

01:01:59.840 | that leads to synaptic vesicle release.

01:02:02.600 | What in the world did I just say?

01:02:04.360 | Well, when your nerve cells communicate with one another,

01:02:07.040 | they do that by way of electricity,

01:02:09.600 | but the electricity within those nerve cells, those neurons,

01:02:12.660 | triggers the release of chemicals from neurons

01:02:15.240 | into the synapse, the little gap between neurons.

01:02:17.720 | And the release of those chemicals

01:02:19.640 | allows the next neuron to be chemically active,

01:02:22.120 | or in some cases,

01:02:23.440 | it will suppress the electrical activity of that next neuron.

01:02:27.000 | Botulinum neurotoxin serves to cut a protein

01:02:31.120 | present in neurons

01:02:32.640 | so that neurons cannot release the chemicals

01:02:35.160 | that cause other neurons to be active.

01:02:37.780 | So this actually is pretty serious.

01:02:39.620 | If you were to get botulinum neurotoxin injected

01:02:42.220 | into your muscle, you would be paralyzed

01:02:44.780 | because the nerves that control contraction of the muscles

01:02:47.180 | would not be able to control the release of that chemical

01:02:50.480 | onto the muscle, which makes it contract.

01:02:52.640 | Botulinum neurotoxin is commonly used

01:02:56.380 | in what's called a Botox.

01:02:57.760 | Botox is something most people are familiar with

01:03:00.120 | because people get it injected in and around their wrinkles,

01:03:04.480 | because many wrinkles are triggered

01:03:07.100 | by not just loss of tensile strength in the skin,

01:03:11.400 | but rather the nerves around the skin and in the skin

01:03:15.600 | are hypercontracted, which causes wrinkles.

01:03:18.160 | So for instance, I have crow's feet.

01:03:19.800 | I like to think that's because I've laughed a lot

01:03:21.580 | and smiled a lot,

01:03:22.640 | and it's probably also because I've squinted a lot

01:03:24.520 | in my lifetime.

01:03:25.900 | I have crow's feet because the nerves there

01:03:28.320 | have pinched the skin on either side of my eyes,

01:03:31.800 | and that's given me little creases there

01:03:34.000 | that are sometimes referred to as crow's feet.

01:03:36.140 | Botox injections can be applied to the scalp

01:03:39.220 | in order to relieve tension of the scalp.

01:03:42.660 | And in hearing that, it should be obvious

01:03:44.200 | why Botox is being used to try and offset hair loss.

01:03:47.820 | It's decreasing the squinting, if you will,

01:03:51.280 | or the tensile nature of the scalp skin

01:03:54.960 | so that more blood flow can arrive

01:03:57.920 | at that stem cell follicle area.

01:04:00.100 | So Botox treatment to the scalp

01:04:01.880 | is actually becoming pretty common.

01:04:03.960 | There are a couple of requirements

01:04:05.160 | with this Botox treatment.

01:04:06.200 | First of all, it has to be done

01:04:07.160 | by somebody who's really skilled.

01:04:09.040 | There are numerous images online and websites online

01:04:13.260 | of so-called Botox fails,

01:04:15.160 | where people have gotten too much Botox

01:04:16.880 | or the injections have been done too deep

01:04:19.360 | or not at the correct locations on people's face or scalp,

01:04:21.920 | and it can give them droopy scalp or droopy eyes,

01:04:24.360 | all sorts of cosmetic nightmares can occur with Botox.

01:04:28.060 | The second thing to understand

01:04:29.000 | is that Botox does eventually wear off.

01:04:31.360 | That botulinum neurotoxin doesn't stick around forever,

01:04:34.420 | and provided it's done correctly at the correct dosages,

01:04:36.920 | it doesn't actually kill the neurons

01:04:38.480 | that cause that tension of the skin.

01:04:40.820 | So Botox injections have to be done repeatedly.

01:04:44.000 | The efficacy of Botox for offsetting hair loss is not clear.

01:04:47.960 | There aren't a lot of large-scale clinical studies

01:04:50.080 | on this just yet,

01:04:51.160 | but it does seem to be at least

01:04:52.200 | one reasonably safe alternative to things like minoxidil.

01:04:55.940 | Although I think if one were to just want

01:04:58.000 | to increase blood flow to the scalp,

01:04:59.840 | things like low-dose tadalafil,

01:05:01.740 | which doesn't seem to carry any of the side effects

01:05:03.800 | that minoxidil can carry,

01:05:05.760 | we talked about those side effects earlier,

01:05:07.580 | that would probably be the better alternative.

01:05:09.680 | Botox is a fairly invasive procedure,

01:05:11.900 | but some people opt for Botox treatment.

01:05:14.040 | In fact, there is a syndrome called cutis verticus gyrata.

01:05:19.040 | Some of you have probably seen this.

01:05:20.680 | It's more typical in men, although it does occur in women.

01:05:23.660 | It literally means a lumping of the skin on the scalp

01:05:27.560 | or gyri of the scalp.

01:05:29.760 | Gyri or gyrus pertains to the Latin word "mi,"

01:05:33.280 | so it means bump or knee.

01:05:35.540 | And so anytime you hear the word gyra in neuroscience

01:05:39.280 | or in biology, you're talking about a bump.

01:05:41.240 | Sometimes see people will have ridges in the back

01:05:43.300 | where it looks as if the skin was pushed together,

01:05:45.440 | kind of like a Sharpay dog, but on the scalp.

01:05:48.920 | People with cutis verticus gyrata

01:05:51.240 | almost always experience pattern hair loss.

01:05:55.040 | Now, part of the reason for that is cutis verticus gyrata

01:05:58.360 | is also associated with some androgen

01:06:01.160 | or testosterone-related hormone issues

01:06:03.400 | that we'll talk about in a little bit.

01:06:05.080 | But in addition to that,

01:06:06.700 | it has been shown that relieving some of those gyrata

01:06:09.560 | by injections of Botox to allow those folds to sit flatter,

01:06:13.600 | A, is effective.

01:06:14.880 | It can lead to less of those gyri, those bumps,

01:06:18.600 | and can improve hair growth in those regions

01:06:21.600 | even if those people don't take on any additional treatments

01:06:25.200 | to address the hormone issues.

01:06:26.800 | So that's really how people arrived at this understanding

01:06:28.960 | that Botox might be a good treatment in general

01:06:31.520 | for reducing the kind of squinting of the scalp

01:06:34.880 | that can occur and the resulting hair loss in those regions.

01:06:38.160 | I'd now like to turn our attention

01:06:39.460 | to the chemical variables

01:06:41.160 | that control the duration of the growth phase of hair,

01:06:44.800 | the duration of that catagen phase,

01:06:46.520 | which is when that hair essentially recedes

01:06:48.760 | from the inside out,

01:06:50.880 | and the quiescent or semiquiescent telogen phase.

01:06:54.920 | There are a couple of key chemical players here

01:06:58.120 | that we should all be aware of.

01:07:00.520 | First of all, the growth factor IGF-1,

01:07:04.460 | insulin growth factor one, which is produced by the liver,

01:07:07.740 | but that receives stimulation from the brain and pituitary

01:07:11.480 | to be released, is a strong regulator of hair growth.

01:07:15.480 | And we can think of it as the accelerator on hair growth.

01:07:19.060 | So it does that by extending that antigen

01:07:22.600 | or growth phase for longer.

01:07:25.120 | It doesn't necessarily speed up growth,

01:07:27.140 | but it extends it for a longer period of time.

01:07:30.480 | In addition, cyclic AMP,

01:07:32.600 | which is part of what's called a second messenger pathway,

01:07:35.000 | in fact, cyclic AMP is a second messenger,

01:07:37.940 | is also a key player in stimulating growth

01:07:40.760 | of the hair follicle.

01:07:41.920 | Now, cyclic AMP does many different things

01:07:43.800 | in many different cell types in the body.

01:07:45.700 | It really acts, as the name suggests,

01:07:48.040 | as a messenger between signals

01:07:50.300 | that arrive at the surface of cells

01:07:52.660 | and transmitting or conveying those signals

01:07:55.680 | to things that happen deep within the cells,

01:07:57.860 | such as the turning on and off of various genes.

01:08:01.060 | So when you hear second messenger,

01:08:02.540 | don't let that confuse you or overwhelm you.

01:08:04.540 | Just understand that the whole process

01:08:07.060 | of getting signals from the outside of cells

01:08:09.140 | into the center of cells and controlling gene expression,

01:08:12.780 | for instance, causing a stem cell

01:08:15.260 | to continue to give off daughter cells

01:08:17.860 | or causing a hair cell to continue growing for longer,

01:08:20.940 | that whole process is a bit like a bucket brigade

01:08:23.140 | of handing off water or a bucket

01:08:24.880 | from one component to the next or along a chain.

01:08:27.760 | It's like an assembly line.

01:08:28.880 | I think that's probably the simplest way to think about it.

01:08:31.160 | So for sake of this discussion,

01:08:32.820 | IGF-1 is known to increase the growth of hair

01:08:36.900 | by extending that antigen phase, as is cyclic AMP.

01:08:40.720 | So those are going to be considered the accelerators,

01:08:43.320 | at least in this conversation.

01:08:45.660 | The breaks on hair growth are going to be the things

01:08:49.700 | that either shorten the antigen phase

01:08:51.800 | or that extend the catagen phase or this quiescent phase,

01:08:55.600 | which is the telogen phase.

01:08:57.660 | And the two major breaks on hair growth

01:09:00.480 | that we want to think about are PDE,

01:09:02.720 | which is a phosphodiesterase, okay?

01:09:05.680 | Anytime you hear ACE, it's likely to be an enzyme,

01:09:07.920 | and TGF-beta-2, all right?

01:09:10.480 | So this is a particular growth factor

01:09:12.560 | that somewhat counterintuitively doesn't stimulate growth.

01:09:15.920 | It actually stimulates lack of growth or shortens growth.

01:09:18.800 | So with all of that in mind,

01:09:20.220 | and please do also keep in mind

01:09:22.960 | that you don't need to remember all those specific terms.

01:09:24.900 | Just understand that there are some factors

01:09:26.760 | like insulin growth factor,

01:09:27.760 | one that act as accelerators on growth,

01:09:30.700 | and there are factors that act as breaks on growth.

01:09:33.820 | We can start to think about why, for instance,

01:09:36.960 | half of all people by age 50 start to lose their hair.

01:09:41.520 | Well, they start to lose their hair

01:09:42.740 | because of something called androgen-related alopecia,

01:09:46.080 | which translated to English means

01:09:49.160 | testosterone and testosterone derivative-induced hair loss.

01:09:53.680 | This is true in men and women.

01:09:55.500 | So hearing that,

01:09:56.340 | you should probably be wondering the following thing.

01:09:59.840 | Young men have higher levels of testosterone

01:10:02.500 | than old men, right?

01:10:04.480 | Well, the answer is yes, although some older men

01:10:07.000 | in their 40s, 50s, even 80s maintain testosterone levels

01:10:10.400 | similar to many men in their 20s, but most don't.

01:10:13.620 | It's a downward slope starting at about age 40.

01:10:17.000 | How steep that downward slope is depends.

01:10:20.480 | Women too have testosterone.

01:10:22.160 | In fact, women have higher levels of testosterone

01:10:25.200 | than they do estrogen.

01:10:27.000 | That's right.

01:10:28.200 | A healthy woman has higher levels of testosterone

01:10:30.640 | than she does estrogen.

01:10:32.140 | However, women on average have lower testosterone

01:10:35.500 | than most men, okay?

01:10:37.020 | So they still have far more estrogen

01:10:39.240 | and far less testosterone than most men,

01:10:41.860 | but the level of testosterone that they have

01:10:44.220 | within their body is higher

01:10:45.940 | than the level of estrogen they have.

01:10:47.740 | Androgens, such as testosterone and its derivatives,

01:10:53.140 | such as dihydrotestosterone,

01:10:55.660 | which will be much the topic

01:10:56.880 | of what we're getting into next,

01:10:59.020 | inhibit IGF-1 and cyclic AMP.

01:11:03.100 | Again, androgens, such as dihydrotestosterone,

01:11:07.460 | inhibit, prevent the action of IGF-1 and cyclic AMP,

01:11:11.680 | which you just learned a few moments ago,

01:11:13.940 | act to extend the antigen or growth phase of hair,

01:11:16.340 | which then raises the question,

01:11:17.840 | well, if young people, both male and female,

01:11:21.400 | have higher levels of testosterone

01:11:23.220 | than they do when they're older,

01:11:25.060 | why would people lose their hair

01:11:26.600 | when they're older and not younger?

01:11:28.740 | Ah, the answer lies in the conversion of testosterone

01:11:32.460 | to dihydrotestosterone.

01:11:34.860 | Testosterone, most people have heard of.

01:11:36.740 | Dihydrotestosterone, or DHT, is made from testosterone.

01:11:41.540 | There's an enzyme called 5-alpha reductase

01:11:44.380 | that converts testosterone into dihydrotestosterone

01:11:46.780 | in both men and women.

01:11:49.180 | Dihydrotestosterone binds to the androgen receptor

01:11:52.840 | at five times the affinity of testosterone.

01:11:55.500 | So it is the most powerful androgen in humans,

01:11:58.880 | and it is responsible for a number of things

01:12:01.140 | that we all really want and like,

01:12:03.400 | such as mental vigor, physical vigor,

01:12:07.340 | strength, healing capacity, drive, libido, and on and on.

01:12:12.340 | So DHT itself is not bad.

01:12:14.620 | So if we take a step back and we acknowledge

01:12:16.820 | testosterone levels are higher in males and females

01:12:19.420 | at younger ages as opposed to older,

01:12:21.220 | but as they get older,

01:12:22.440 | there is more 5-alpha reductase activity,

01:12:25.080 | which is converting more of that testosterone

01:12:26.940 | to dihydrotestosterone,

01:12:28.360 | and dihydrotestosterone inhibits hair growth

01:12:30.800 | by reducing IGF-1 and cyclic AMP,

01:12:33.320 | well, then we should all be aboard why it is that by age 50,

01:12:37.180 | about 50% of people experience pattern hair loss.

01:12:40.780 | That is androgen-dependent alopecia, okay?

01:12:44.040 | But translated to normal English is pattern hair loss.

01:12:48.000 | And in a moment, you'll understand why

01:12:49.680 | some people lose their hair from the crown region,

01:12:52.840 | in the back of the head or back and top of the head,

01:12:55.500 | whereas other people lose their hair

01:12:57.420 | in the front of their head,

01:12:59.220 | in the flanks right on either side of the midline

01:13:02.940 | or maybe in the midline and front altogether.

01:13:06.100 | And that's because different people,

01:13:08.200 | depending on their genetic lineage,

01:13:10.220 | have different patterns of androgen receptors

01:13:12.360 | on their scalp.

01:13:13.820 | And the pattern of androgen receptors that you inherit

01:13:16.860 | indeed does come from your mother's side.

01:13:19.740 | And so this is what gave rise to the myth

01:13:22.140 | that if you want to know if you're going to go bald or not,

01:13:24.320 | just look at your mother's father.

01:13:26.300 | Doesn't quite work that way.

01:13:27.420 | In fact, if you think about the logic,

01:13:29.860 | you should really look at your mother's mother

01:13:32.460 | if you want to know your pattern of androgen receptors

01:13:36.100 | on your scalp.

01:13:36.940 | However, most women don't lose as much hair

01:13:39.160 | from their scalp or they have ways

01:13:41.460 | of covering up the hair loss in their scalp

01:13:43.360 | because their hair is just generally longer

01:13:45.080 | or they're using other approaches

01:13:46.620 | so that you never really get a clear picture

01:13:48.580 | of what the androgen-dependent hair loss was

01:13:51.760 | in your grandmother, okay?

01:13:54.040 | Now, we don't want to go too far down

01:13:55.300 | the genetics rabbit hole because, as you know,

01:13:57.540 | you can't select your parents anyway.

01:13:59.740 | But if you want to know why, for instance,

01:14:01.740 | I'm losing a bit of hair on either side of the midline

01:14:04.580 | in the front, it almost certainly has to do with the fact

01:14:08.220 | that I have a higher density of androgen receptors there

01:14:10.940 | as opposed to, say, on the crown of my head

01:14:12.900 | where, for whatever reason, my hair seems to grow thickest.

01:14:15.600 | Other people lose hair on the crown in the back and top,

01:14:18.980 | but not in the front, and some people lose it all over.

01:14:22.280 | Now you understand why hair loss occurs

01:14:24.520 | in certain regions of the body.

01:14:26.720 | You should also understand that the androgen receptors

01:14:29.540 | on the face are also what are responsible for beard growth.

01:14:33.260 | And this is where it can get a little bit tricky,

01:14:35.000 | but a lot of things will start to make sense

01:14:36.620 | if you can understand this and internalize this.

01:14:39.480 | If you have a high density of androgen receptors

01:14:41.800 | on your face, well then, as your DHT levels go up with age,

01:14:45.600 | you will be able to grow a thicker and thicker beard.

01:14:48.500 | In fact, it is rare to see someone who can grow a thick beard

01:14:52.040 | in their youth, but not so much as they get older.

01:14:54.520 | In fact, the reverse tends to be true.

01:14:56.300 | So the pattern of androgen receptors differs

01:14:58.200 | between the scalp and the face and the back, okay?

01:15:02.200 | On your back, you have androgen receptors,

01:15:04.080 | and there, DHT stimulates hair growth.

01:15:06.080 | So if you know someone who has a very hairy back,

01:15:08.080 | or if you have a very hairy back,

01:15:09.640 | that means you have a high density

01:15:10.540 | of androgen receptors on your back.

01:15:12.400 | If you have a beard and that beard is thick, well then,

01:15:15.240 | you have a high density of androgen receptors on your face.

01:15:18.000 | However, a high density of androgen receptors anywhere

01:15:20.740 | on your scalp is going to predispose those regions

01:15:23.620 | to androgen-dependent alopecia or hair loss

01:15:26.740 | in those particular regions,

01:15:28.520 | which is going to allow us to understand why all

01:15:31.180 | of the rest of the treatments for halting hair loss

01:15:34.700 | and for stimulating hair growth,

01:15:36.400 | almost all of those center on inhibiting either DHT directly

01:15:42.240 | or 5-alpha reductase, the conversion of testosterone to DHT.

01:15:46.700 | So now I'd like to discuss the ways

01:15:47.980 | that one can chemically adjust certain things

01:15:50.720 | within the hair growth pathway,

01:15:53.240 | things like IGF-1, PDE, TGF-beta, et cetera,

01:15:57.480 | in order to stimulate hair growth or halt hair loss.

01:16:00.620 | The first thing on this list is actually going

01:16:02.200 | to be pretty surprising to a number of you,

01:16:04.420 | and that's caffeine.

01:16:06.200 | We all think of caffeine as a stimulant that we drink.

01:16:08.760 | I certainly drink coffee and yerba mate,

01:16:10.820 | the occasional energy drink, things of that sort.

01:16:12.960 | Caffeine does many things besides stimulate

01:16:15.420 | our central nervous system and make us feel less sleepy.

01:16:17.780 | However, one of the things that caffeine does

01:16:20.800 | is it is a fairly potent PDE inhibitor.

01:16:24.600 | By being a potent PDE inhibitor,

01:16:27.800 | it indirectly stimulates IGF-1.

01:16:30.680 | Why?

01:16:31.520 | Well, because PDE can suppress IGF-1,

01:16:35.960 | and by ingesting caffeine

01:16:38.280 | or by applying topical caffeine ointment

01:16:42.180 | or cream to the scalp, you can suppress PDE sufficiently

01:16:46.040 | enough to increase IGF-1 and increase some hair growth

01:16:49.440 | or at least maintain hair growth in that region.

01:16:52.880 | This may come as a shock.

01:16:54.360 | It might seem a little bit esoteric

01:16:56.320 | or even outside the margins of typical treatments,

01:16:59.480 | but head-to-head topical caffeine application

01:17:02.380 | can be as effective as minoxidil application

01:17:05.320 | without actually lowering things like blood pressure

01:17:08.000 | and potentially increasing prolactin

01:17:11.040 | and some of the other negative, let's call them negative

01:17:13.720 | because they are side effects of minoxidil.

01:17:16.620 | So caffeine ointments and caffeine present

01:17:19.760 | in various hair treatments and creams, et cetera,

01:17:22.640 | is starting to become a more prominent theme out there.

01:17:25.700 | I will include a reference to caffeine

01:17:28.240 | and its uses for offsetting hair loss.

01:17:30.260 | Keep in mind that topical caffeine ointments

01:17:32.120 | shouldn't necessarily be applied every single day.

01:17:34.660 | So this is the sort of thing you might do

01:17:35.960 | three times a week.

01:17:37.220 | The concentration of caffeine in different ointments

01:17:39.140 | varies tremendously.

01:17:40.540 | Most of the studies of caffeine on the stem cell niches

01:17:43.920 | that control hair growth

01:17:44.920 | and extension of the antigen phase of hair growth

01:17:47.300 | have been performed in vitro in a dish.

01:17:49.320 | Although there are some clinical studies exploring this,

01:17:52.620 | they are not nearly as extensive in number or duration

01:17:55.640 | as the studies of minoxidil

01:17:57.020 | because this approach just hasn't been around quite as long.

01:17:59.740 | However, when comparing side effects of minoxidil,

01:18:02.300 | cost of minoxidil,

01:18:03.740 | comparing the efficacy of caffeine and minoxidil,

01:18:06.260 | I think caffeine as a topical treatment

01:18:08.320 | for offsetting hair loss

01:18:09.980 | stands as a pretty good choice

01:18:11.660 | if you're going to start exploring this pathway.

01:18:13.980 | And there's no reason to think

01:18:14.980 | that if you were to try the caffeine ointment

01:18:16.880 | and it didn't work for you,

01:18:17.880 | or you didn't like it for some reason,

01:18:19.160 | or you needed to stop it for some reason,

01:18:20.980 | that you couldn't stop it safely

01:18:22.400 | because it doesn't carry all the other

01:18:24.540 | kind of blood pressure related effects

01:18:26.240 | and prolactinemia effects that minoxidil does.

01:18:29.260 | So if you look out there into the hair maintenance

01:18:31.900 | and hair replacement literature,

01:18:34.220 | you look at the treatments that are being sold,

01:18:35.580 | don't be surprised to see caffeine there.

01:18:37.740 | And also don't be surprised when I tell you

01:18:40.020 | what I'm about to tell you now,

01:18:41.020 | which is no, you can't simply just drink more caffeine

01:18:43.980 | in order to accomplish the goal of offsetting hair loss.

01:18:47.440 | It is true that when you ingest caffeine,

01:18:49.100 | it goes systemically.

01:18:50.460 | However, you have so many adenosine receptors

01:18:53.180 | throughout your body,

01:18:54.060 | those adenosine receptors and the parking of caffeine

01:18:56.860 | in those adenosine receptors is the main way

01:18:58.940 | in which caffeine exerts its stimulatory effects,

01:19:01.280 | making you feel less sleepy.

01:19:03.260 | So it does that because then adenosine

01:19:05.700 | can't have its effects, which are to make you sleepy.

01:19:08.360 | Well, those adenosine receptors soak up

01:19:11.200 | so much of the caffeine that you would ingest orally

01:19:13.840 | that very, very little would make it to the scalp

01:19:17.820 | and to the hair follicles

01:19:19.100 | at the concentrations that you would want.

01:19:20.740 | So that's why you have to rely on the application

01:19:22.780 | of these caffeine ointments about three times a week.

01:19:26.100 | Keep in mind that no one has really explored the dosages

01:19:28.940 | of caffeine in these ointments in a systematic way.

01:19:31.300 | We're still in the early stages of all this,

01:19:33.660 | but I do think it's important to mention caffeine

01:19:35.380 | because of the lower incidence of side effects,

01:19:38.000 | at least reported side effects,

01:19:39.260 | and the general safety margins and the head-to-head,

01:19:42.380 | essentially comparable efficacy with minoxidil

01:19:44.580 | because minoxidil has a bunch of other issues.

01:19:46.940 | Now, keep in mind that both minoxidil and caffeine

01:19:49.800 | are generally used as a preventative

01:19:52.380 | for reducing hair loss over time.

01:19:55.260 | They are not expected and they do not, as far as we know,

01:19:59.660 | create new hair growth to any sufficient degree.

01:20:03.200 | If any of you have used caffeine ointments

01:20:05.020 | or minoxidil and observed new hair growth that was robust,

01:20:08.420 | please put that in the comment section.

01:20:09.780 | I'd be curious about those experiences.

01:20:11.700 | But as far as I know,

01:20:12.540 | and from the clinical literature that I read,

01:20:14.720 | there's no examples of that.

01:20:16.340 | One other point about caffeine,

01:20:18.100 | it does appear that caffeine can not only

01:20:20.540 | indirectly stimulate IGF-1 in the antigen phase

01:20:23.180 | of hair cell growth by way of reducing PDE and TGF-beta,

01:20:27.380 | but it also seems to reduce apoptosis,

01:20:30.140 | which is naturally occurring cell death

01:20:32.140 | of that stem cell niche.

01:20:33.660 | We've been talking a lot about the antigen

01:20:34.980 | or growth phase of hair.

01:20:36.120 | We also talked about the catagen,

01:20:37.740 | or the recession of that hair from the inside out.

01:20:40.420 | But remember that third phase, the telogen phase,

01:20:42.740 | where that whole bulb down at the bottom,

01:20:44.520 | the bulges it's called, gets pinched off

01:20:46.540 | and the whole thing dies

01:20:47.420 | and takes the stem cells off to the grave with it.

01:20:49.860 | It appears that caffeine can offset the death of that niche

01:20:53.420 | and potentially maintain the stem cell population longer,

01:20:56.860 | making caffeine a really good choice to think about

01:20:59.820 | in conjunction with the various chemical treatments

01:21:02.300 | aimed at directly attacking the DHT pathway

01:21:05.380 | that we'll talk about next.

01:21:06.780 | So there's one very direct way to increase hair growth

01:21:09.620 | and maintain the hair that you have on your head,

01:21:12.460 | and that's to increase IGF-1.

01:21:15.080 | That can be accomplished through prescription drugs,

01:21:17.860 | such as growth hormone and things that stimulate

01:21:21.240 | the release of growth hormone and IGF-1.

01:21:23.920 | Keep in mind, growth hormone is released

01:21:25.480 | from the anterior pituitary during the first hours of sleep,

01:21:28.900 | especially when you haven't eaten anything

01:21:30.620 | for the two hours prior to sleep,

01:21:32.780 | and especially when you get regular bedtimes.

01:21:35.780 | Yes, this is a real thing.

01:21:37.440 | If you are going to sleep at variable bedtimes,

01:21:40.480 | especially if you go to sleep much later

01:21:42.080 | than your usual habitual bedtime,

01:21:44.020 | you will miss that growth hormone pulse

01:21:45.820 | that normally occurs in the first two to three hours

01:21:48.840 | of sleep.

01:21:49.680 | This does not mean that you need to be neurotic

01:21:51.220 | about getting to sleep at the exact same time every night.

01:21:53.260 | There's probably a plus or minus 30 minute window,

01:21:56.560 | and it doesn't mean that you can't stay out late

01:21:58.520 | or have a bad night's sleep every once in a while

01:22:01.000 | or get woken up.

01:22:02.200 | Your hair isn't going to fall out.

01:22:03.720 | My dad's story notwithstanding.

01:22:06.320 | Your hair isn't going to all fall out because of that,

01:22:08.280 | but you do want to try and get

01:22:09.720 | that natural growth hormone release each night,

01:22:11.960 | and as I mentioned, there are prescription approaches,

01:22:14.960 | and those are growth hormone itself

01:22:17.520 | and things like sermorelin,

01:22:19.800 | which is a peptide that increases growth hormone.

01:22:22.120 | It's actually a secretogog.

01:22:23.920 | It causes the secretion of growth hormone

01:22:26.480 | and thereby increases in IGF-1.

01:22:28.680 | This is well-documented.

01:22:30.000 | Both growth hormone and IGF-1, as I mentioned,

01:22:32.640 | are available by prescription.

01:22:34.280 | They are not without their side effects.

01:22:36.760 | So they do cause growth of all tissues.

01:22:38.980 | They do increase height in children.

01:22:40.760 | They increase bone mass and density.

01:22:42.900 | They can increase mainly fat loss, not so much muscle size,

01:22:46.400 | but they can increase leanness,

01:22:48.120 | and they increase hair growth.

01:22:49.800 | They can increase turnover of skin.

01:22:51.400 | They can make skin look more youthful.

01:22:52.860 | All these things sound wonderful,

01:22:54.680 | and yet they also have problems

01:22:57.060 | because they can increase growth of small tumors

01:22:59.740 | that normally might be eliminated.

01:23:01.040 | So there is an increased cancer risk

01:23:03.200 | with growth hormone treatments in IGF-1

01:23:06.200 | or anything that increases IGF-1,

01:23:08.120 | such as sermorelin, ipramarolin,

01:23:10.400 | any of the peptides that you hear about nowadays.

01:23:12.880 | That said, a number of people are using sermorelin

01:23:15.040 | as an indirect way to increase IGF-1

01:23:17.660 | and thereby to increase hair growth.

01:23:19.200 | It does seem to be fairly effective in doing that,

01:23:22.200 | especially when done in conjunction

01:23:23.680 | with other treatments that we'll talk about,

01:23:25.360 | but keep in mind, these are prescription drugs

01:23:27.360 | and they do carry their own risks.

01:23:29.220 | The other thing about stimulating

01:23:30.500 | the natural production of IGF-1

01:23:32.560 | is that as its name suggests, insulin growth factor one,

01:23:35.920 | it is insulin dependent in many ways,

01:23:38.360 | if not for its secretion,

01:23:39.640 | then for its action at the hair, follicle, and stem cell.

01:23:43.560 | So one of the things you really want to pay attention to

01:23:45.560 | is to avoid being insulin resistant,

01:23:48.560 | or rather you want to try to be insulin sensitive.

01:23:51.520 | So if you're carrying a lot of excess body fat,

01:23:53.840 | if you're obese, or if you have type two diabetes,

01:23:56.440 | meaning you're insulin resistant,

01:23:57.620 | you're going to want to deal with that.

01:23:59.120 | There are a number of prescription treatments

01:24:00.320 | to deal with that.

01:24:01.240 | Nowadays, people are very excited

01:24:02.640 | about all the GLP-1 agonists,

01:24:04.320 | but in addition to that,

01:24:06.000 | regular cardiovascular exercise and resistance exercise,

01:24:09.240 | making sure that your body fat percentage

01:24:11.040 | is not in excess of where it needs to be,

01:24:14.300 | and everyone has a slightly different idea

01:24:16.720 | of where it needs to be, both cosmetically and for health.

01:24:19.120 | So that's a conversation between you and your doctor

01:24:21.120 | and you and you, frankly,

01:24:23.060 | but you want to avoid being insulin resistant

01:24:26.260 | because being insulin resistant and being obese

01:24:28.800 | can indeed lead to hair loss.

01:24:30.560 | And there are many people out there who are not obese,

01:24:32.920 | who nonetheless are experiencing hair thinning and hair loss

01:24:36.180 | because they are insulin resistant

01:24:38.120 | by way of reduced IGF-1 activity.

01:24:40.720 | There are a few supplements,

01:24:41.960 | so these are over-the-counter supplements,

01:24:43.240 | such as myo-inositol,

01:24:44.660 | taken at dosages of about 900 milligrams before sleep,

01:24:48.120 | which by the way can also assist in sleep,

01:24:50.560 | or things like berberine or metformin,

01:24:53.920 | which are known to improve insulin sensitivity.

01:24:56.160 | Each and every one of these has its own profile

01:24:58.800 | of positive and negative effects.

01:25:00.960 | The lowest number of side effects

01:25:03.060 | is associated with 900 milligram myo-inositol

01:25:06.680 | taken about 30 minutes before sleep,

01:25:08.280 | mostly because it can make people a little bit drowsy,

01:25:10.840 | and it does aid sleep in some really great ways,

01:25:13.680 | but really exercise and maintaining

01:25:15.440 | a healthy nutritional program are also going to be key.

01:25:18.160 | You just can't discard those.

01:25:19.840 | Berberine, which is a substance made from tree bark,

01:25:22.160 | is sometimes called the poor man's metformin,

01:25:24.160 | metformin being the equally effective

01:25:27.360 | prescription version of berberine.

01:25:29.280 | More put differently, berberine is the non-prescription,

01:25:31.900 | but equally effective version of metformin.

01:25:34.740 | Keep in mind that both berberine and metformin

01:25:37.440 | dramatically reduce blood sugar levels,

01:25:39.580 | and so if you're not going to take them with carbohydrates,

01:25:41.440 | it can lead to some feelings of discomfort.

01:25:43.440 | That's why I'm not a fan of them,

01:25:44.800 | but if your goal is to really improve insulin sensitivity,

01:25:48.100 | they are considered very potent tools

01:25:50.620 | on the list of things that can do that.

01:25:52.320 | The other thing that's really important

01:25:53.620 | for maintaining proper hair growth, this antigen phase,

01:25:55.900 | is that you need sufficient iron.

01:25:58.100 | This is because iron and ferritin play a key role

01:26:02.200 | in the cell growth pathways that go from the stem cells

01:26:05.780 | to the stimulation of keratin within the hair itself.

01:26:08.820 | Don't have time to go into this pathway in a lot of detail,

01:26:11.400 | but you can have your blood levels of iron measured.

01:26:14.380 | This turns out to be pretty important

01:26:15.780 | because you don't just want to start

01:26:16.800 | popping iron supplements because too much iron can be toxic,

01:26:19.680 | too little, means you're anemic.

01:26:21.800 | For women, the levels of iron that you want

01:26:25.080 | are somewhere between 25 and 100,

01:26:27.320 | and for men, somewhere between 30 and 150.

01:26:30.180 | Fortunately, the tests or the blood tests for iron

01:26:32.840 | are usually a very inexpensive add

01:26:35.920 | to your current blood panel.

01:26:37.320 | So if you're going in for a blood panel for LDL, HDL,

01:26:40.120 | kind of typical things,

01:26:40.940 | or if you're doing the more elaborate hormone testing,

01:26:43.880 | which I do recommend people do if they can afford it

01:26:45.760 | or if their insurance covers it,

01:26:47.280 | do ask for an iron test as well.

01:26:48.880 | And if your iron is low,

01:26:49.780 | you may need to supplement your iron.

01:26:51.460 | If your iron is too high, that's not good either.

01:26:53.640 | But iron plays a key role in the antigen phase

01:26:57.040 | of hair growth.

01:26:57.880 | So you want to make sure you at least have sufficient iron.

01:27:00.360 | And if you don't, you want to make sure

01:27:01.520 | that you're getting it from nutrition

01:27:02.800 | and/or supplementation.

01:27:04.440 | Okay, so earlier we were talking about dihydrotestosterone.

01:27:07.360 | Dihydrotestosterone, just to jog your memory,

01:27:10.040 | is a form of testosterone that can bind the androgen receptor

01:27:13.220 | at five times the affinity of regular testosterone.

01:27:16.440 | Both men and women have a lot of testosterone

01:27:20.280 | relative to estrogen.

01:27:21.520 | It just so happens that men tend to have more testosterone

01:27:24.000 | than women do overall.

01:27:25.760 | But both men and women, as they age,

01:27:28.780 | convert more of the testosterone they have

01:27:31.420 | to dihydrotestosterone.

01:27:33.000 | And dihydrotestosterone does two things

01:27:35.620 | that are bad for hair maintenance and hair growth.

01:27:37.980 | First of all, it shortens the antigen phase,

01:27:40.860 | that growth phase.

01:27:42.040 | So whatever hair is going to grow

01:27:43.380 | is going to occur over a shorter period of time.

01:27:46.340 | Second of all, because of the presence of androgen receptors

01:27:50.260 | on the stem cell niche area and around it,

01:27:53.780 | it actually miniaturizes the follicle

01:27:56.080 | and the stem cell niche.

01:27:57.700 | In other words, it makes the population of cells

01:27:59.700 | that give rise to more hair protein smaller

01:28:02.940 | and can eliminate it altogether.

01:28:04.980 | And that is why anything that reduces 5-alpha reductase

01:28:08.200 | is going to reduce DHT, is going to maintain

01:28:11.460 | or extend the growth phase,

01:28:13.660 | the antigen phase of hair growth,

01:28:15.340 | and is going to offset or prevent

01:28:17.640 | some of the telogen phase,

01:28:19.740 | the pinching off and the removal of that stem cell niche.

01:28:23.460 | Now, one substance that we know

01:28:24.780 | can inhibit 5-alpha reductase,

01:28:26.600 | although it does it pretty weakly, is solpalmetto,

01:28:29.980 | which is an extract of the solpalmetto berry.

01:28:32.740 | To be honest, I don't know how this was initially discovered.

01:28:35.180 | If anyone knows, please put it in the show note captions.

01:28:37.540 | When I looked online, I found a bunch of conflicting stories

01:28:40.040 | about who was the first person

01:28:41.900 | to start extracting the extract of the solpalmetto berries.

01:28:46.200 | So I have no idea which one of those is true.

01:28:48.500 | Maybe somebody can tell me.

01:28:50.460 | The good thing about solpalmetto treatment

01:28:52.300 | is that it is known to have very few, if any, side effects.

01:28:55.860 | There might be some side effects in about 1% of people,

01:28:58.300 | but it's not associated with a lot of side effects.

01:29:01.700 | It's also known that when taken

01:29:03.500 | at about 300 milligrams per day,

01:29:05.880 | and here it doesn't have to be that strict.

01:29:07.340 | Most of the studies that I explored

01:29:09.420 | involve taking anywhere from 200 to 500 milligrams

01:29:12.680 | of solpalmetto, but most of them focused

01:29:14.720 | on about 300 milligrams of solpalmetto per day,

01:29:17.480 | divided into two or three doses.

01:29:19.200 | Why?

01:29:20.040 | Well, it has a relatively short half-life,

01:29:22.440 | meaning it's going to get cleared from the bloodstream,

01:29:24.120 | and more importantly, its biological action

01:29:25.980 | is going to be very short-lived.

01:29:27.500 | So if you can get ahold of 50 or 100 milligram capsules

01:29:31.320 | or tablets of solpalmetto and divide those up,

01:29:34.200 | taking them in the morning, afternoon, and evening,

01:29:36.540 | or even just in the morning and evening

01:29:37.940 | to achieve a total of about 300 milligrams per day,

01:29:41.300 | that's going to very likely help you hold on

01:29:44.680 | to some of the hair that you would have otherwise lost,

01:29:47.620 | maybe even grow some new hair.

01:29:49.400 | And I say maybe give you some new hair growth

01:29:51.780 | because solpalmetto is not known

01:29:53.560 | to be a particularly robust treatment

01:29:56.220 | for the reversal of hair loss.

01:29:57.620 | It's known to have some effect,

01:29:59.280 | but it's generally taken in conjunction

01:30:01.140 | with a bunch of other things.

01:30:03.120 | And so it's really hard to tease out

01:30:04.660 | just what amount of hair growth

01:30:06.860 | or prevention of hair loss

01:30:08.700 | is due to solpalmetto specifically.

01:30:10.860 | But I mention it here because the mechanism of action

01:30:13.380 | is logical and fairly well-known,

01:30:15.300 | which is this weak effect in reducing 5-alpha reductase

01:30:19.100 | and thereby reducing DHT.

01:30:21.020 | So again, because it has relatively low side effects,

01:30:23.740 | even though it's not super effective,

01:30:25.620 | and because it's fairly low cost

01:30:27.040 | and it's available over the counter,

01:30:29.580 | I felt it was important to include.

01:30:32.040 | Now, as soon as people hear things like solpalmetto berry,

01:30:34.660 | they're probably also thinking,

01:30:35.860 | "Oh boy, here come all the herbals."

01:30:37.900 | Now, keep in mind that there are some herbal compounds

01:30:40.320 | that have pretty robust biological effects.

01:30:42.940 | And we talked before

01:30:43.780 | in our optimizing testosterone episodes

01:30:46.540 | about things like Tonga Ali and Fidogia agrestis,

01:30:49.620 | which taken in correct dosages and in the correct way

01:30:52.700 | can be pretty potent for increasing luteinizing hormone

01:30:55.260 | and free testosterone.

01:30:56.780 | Not going to have huge effects.

01:30:57.980 | It's not like taking exogenous anabolic steroids,

01:31:00.020 | but they can have real effects.

01:31:01.840 | And so herbal compounds can be potent.

01:31:04.660 | However, I do acknowledge that there's a vast market

01:31:07.540 | out there of herbal compounds and plant-based compounds

01:31:10.680 | that people are arguing,

01:31:12.200 | mostly the people who sell them are arguing,

01:31:14.420 | can increase hair growth.

01:31:15.740 | And there are some decent studies of these things.

01:31:18.300 | The hard part about studying these herbal compounds

01:31:21.460 | and these plant-derived compounds for increasing hair growth

01:31:24.180 | is that they are often taken in combination

01:31:26.440 | with one another.

01:31:27.460 | In fact, most of the hair growth supplements

01:31:30.620 | that involve these herbal compounds and plant compounds

01:31:33.560 | include five or 10, sometimes even more things altogether.

01:31:37.340 | So teasing out which ones are effective

01:31:39.080 | and which dosages are effective is nearly impossible.

01:31:41.800 | They're just too many variables.

01:31:43.280 | So you will hear, for instance, that green tea extract,

01:31:46.380 | Reisi mushroom, pumpkin oil, zinc, curcumin,

01:31:50.580 | that all of these things can increase hair growth.

01:31:53.980 | Perhaps the only thing on that list that makes logical sense

01:31:56.500 | with respect to the biochemistry is that curcumin

01:31:59.360 | is known to in some people be a potent inhibitor,

01:32:03.060 | a five alpha reductase and DHT.

01:32:04.940 | So much so that I can personally say for me,

01:32:07.320 | I once took curcumin, turmeric, it's also called,

01:32:11.540 | in high dosage.

01:32:12.700 | This is about a gram to two gram capsules.

01:32:14.860 | And I felt absolutely terrible.

01:32:17.020 | I mean, just dreadful.

01:32:18.280 | I don't care if it allowed me to keep my hair forever.

01:32:20.700 | I would rather lose all my hair three times over.

01:32:23.740 | Well, I guess that means it would have grown back.

01:32:25.380 | I'd rather lose all my hair, let's just put it that way,

01:32:28.720 | than ever take curcumin or turmeric in high dosages again.

01:32:31.860 | And in saying that, I know that many people

01:32:33.620 | take turmeric and curcumin

01:32:35.020 | and really like its anti-inflammatory properties

01:32:37.660 | and don't experience any side effects.

01:32:39.500 | I just happen to be particularly sensitive to curcumin

01:32:42.220 | by way of this DHT pathway.

01:32:44.060 | And I know this by way of blood work.

01:32:45.340 | So I'm never going near that stuff again.

01:32:47.400 | That said, a lot of these herbal compounds and cocktails

01:32:51.660 | probably will have some minor marginal infinitesimally small,

01:32:56.660 | somewhere in that range effect on maintaining hair growth

01:33:00.240 | or in stimulating new hair growth.

01:33:02.940 | It's just that there really aren't clinical studies

01:33:04.900 | to support any one of them.

01:33:06.060 | And that's why I singled out Saul Palmetto

01:33:07.980 | as one of the few for which the biochemical pathway

01:33:10.380 | of inhibiting foul for reductase

01:33:12.360 | and the low incidence of side effects

01:33:14.440 | and the fact that many people have used it

01:33:16.220 | with some degree of success makes it a standalone,

01:33:19.640 | I wouldn't say recommendation, but a consideration.

01:33:22.380 | Another commonly discussed and used commercial compound

01:33:25.880 | for offsetting hair loss and stimulating hair growth

01:33:28.280 | is ketoconazole.

01:33:30.140 | Sometimes this is known as nizoral,

01:33:32.220 | where nizoral is the brand name of a shampoo.

01:33:35.380 | Ketoconazole is an antifungal that was initially developed

01:33:38.920 | to treat dandruff and severe psoriasis.

01:33:42.140 | So ketoconazole has been shown to be effective

01:33:44.180 | in increasing hair number.

01:33:46.840 | It's also been shown to be effective

01:33:48.360 | in increasing hair diameter, which is somewhat surprising

01:33:51.720 | because one of the common side effects of ketoconazole

01:33:54.480 | is drying, shinning and brittle hair.

01:33:57.560 | So what's going on there is a little unclear.

01:33:59.520 | We'll return to that in a moment.

01:34:01.240 | The mechanism of action for ketoconazole

01:34:03.240 | is pretty interesting.

01:34:04.320 | Remember earlier we were talking about the sebaceous gland

01:34:06.600 | and the production of sebum, that oily stuff,

01:34:09.340 | whose very name seems to evoke disgust in certain people.

01:34:12.260 | Well, ketoconazole can disrupt some of the fungal growth

01:34:15.620 | that frankly we all have on our scalp all the time.

01:34:18.700 | I know this is a surprise to many of you,

01:34:20.340 | but you are constantly bombarded with viruses,

01:34:24.060 | bacteria and funguses all the time,

01:34:26.740 | but we managed to battle those off with our immune system

01:34:29.020 | either by physical barriers, such as an oil barrier,

01:34:31.520 | like the sebum or through antimicrobial action.

01:34:35.160 | So chemical approaches, our immune system,

01:34:37.560 | the sebum, et cetera.

01:34:38.980 | Ketoconazole acts as an antifungal that in some way

01:34:42.760 | seems to reinforce the properties of sebum

01:34:45.460 | at keeping out other fungal infections.

01:34:48.000 | And the net effect, at least as far as we know,

01:34:50.920 | is a mild reduction in DHT.

01:34:53.380 | Now exactly how this happens isn't really clear.

01:34:56.000 | What is clear is that the use of ketoconazole shampoos

01:34:59.660 | two to four times per week with a scalp contact time

01:35:04.460 | of about three to five minutes has been shown

01:35:06.920 | to give about an 80% response rate of maintaining hair

01:35:11.000 | that would otherwise be lost.

01:35:12.400 | So that's pretty dramatic, 80%.

01:35:14.480 | What is less clear is whether or not ketoconazole shampoo

01:35:17.060 | can actually stimulate new hair growth.

01:35:19.600 | But as you're probably starting to realize,

01:35:21.560 | this is always a bit of a tough thing to disentangle.

01:35:23.940 | Maintenance of hair that you would have lost

01:35:26.300 | versus new hair growth.

01:35:27.740 | Certainly that's an easy thing to disambiguate

01:35:30.060 | if you have a patch of scalp

01:35:31.440 | where there is absolutely no hair.

01:35:33.460 | These so-called dead zones that you can resurrect

01:35:36.900 | with certain treatments.

01:35:38.260 | But what about areas of your scalp where hair is thinning?

01:35:41.220 | So for instance, on the top of your head,

01:35:43.420 | this is where many women will first experience

01:35:45.540 | pattern hair loss.

01:35:46.780 | Alopecia is right at their midline.

01:35:50.480 | Especially if they have a part right there,

01:35:51.840 | they'll start to notice that under very bright light

01:35:53.780 | fluorescent lights in particular,

01:35:55.060 | they'll notice that thinning of their hair there

01:35:56.600 | or in the forehead region.

01:35:58.080 | They'll start using ketoconazole shampoo.

01:36:01.980 | Again, the typical recommendation

01:36:03.940 | is two to four times per week

01:36:05.300 | with a scalp contact time of three to five minutes

01:36:07.360 | and really rubbing it in and then rinsing it out.

01:36:09.500 | You don't need to be super vigorous,

01:36:10.800 | but you want to make sure that it gets down into the follicle

01:36:13.100 | and around the follicles,

01:36:14.580 | not just sitting on top of the hair,

01:36:16.580 | which is going to be especially important

01:36:18.480 | for people who have long hair to really massage it in.

01:36:21.640 | Well, they will experience a growth of hair

01:36:24.020 | in that particular region that almost certainly

01:36:26.580 | were due to miniaturization of the hair follicle

01:36:29.060 | and reduction of the total population of stem cells

01:36:31.960 | in that follicle,

01:36:33.040 | as opposed to complete loss of the stem cell population.

01:36:36.200 | The reason we say this is that there's no reason to think

01:36:37.960 | that ketoconazole can actually stimulate IGF-1

01:36:40.740 | or activate growth itself.

01:36:42.800 | It's probably offsetting some of the reductions

01:36:45.360 | in the antigen phase and some of the exacerbation

01:36:48.740 | of the telogen phase.

01:36:50.040 | Now, if you decide to use ketoconazole

01:36:51.800 | as an approach to offsetting hair loss,

01:36:53.300 | it's very important that you get a hold of a shampoo

01:36:55.900 | that's at least 2% concentration of ketoconazole.

01:36:59.540 | This is important because a lot of the ones

01:37:01.460 | that are available out there, especially online,

01:37:04.000 | are going to be 1% or lower.

01:37:05.980 | So you want to try and obtain a ketoconazole shampoo

01:37:08.140 | of 2% or higher concentration of ketoconazole

01:37:12.000 | 'cause it has other things in it, of course.

01:37:14.200 | I should mention that there are occasional side effects

01:37:16.620 | with ketoconazole.

01:37:17.640 | The rates of side effects from the meta-analyses

01:37:19.920 | and reviews that I read were somewhere between 1% and 8%

01:37:23.360 | of people will experience some side effects,

01:37:25.020 | but those side effects tend to be pretty mild.

01:37:27.440 | Things like irritation of the scalp,

01:37:29.600 | things like thinning and brittleness of the hair

01:37:32.480 | that sometimes can be offset by using shampoos

01:37:34.720 | that contain things like biotin.

01:37:36.240 | I know many people are probably curious about biotin,

01:37:38.320 | which is a protein that can be incorporated

01:37:40.200 | into the keratin.

01:37:41.380 | Whether or not different biotin-enriched shampoos

01:37:45.320 | can really enhance the total amount of biotin

01:37:48.000 | that gets incorporated into the hair

01:37:49.780 | isn't clear, but it is clear

01:37:51.520 | that having sufficient biotin around is important.

01:37:54.200 | So if you get a little bit extra from your shampoo,

01:37:56.660 | you can imagine how that would, quote unquote,

01:37:58.120 | tap off the amount of biotin in that hair.

01:38:00.560 | And there are people out there saying that biotin-enriched

01:38:03.100 | shampoos have done wonders for them, who knows?

01:38:05.880 | I'm not going to dispute their experience.

01:38:08.360 | So if you're going to use ketoconazole,

01:38:10.520 | keep in mind that the more typical brand names

01:38:13.700 | that are out there, you know which ones they are,

01:38:15.760 | oftentimes don't have 2%.

01:38:18.400 | Or if they do have 2%, they can be very drying

01:38:21.480 | and lead to brittle hair.

01:38:22.880 | There are newer and now fortunately a greater variety

01:38:27.760 | of ketoconazole-containing shampoos.

01:38:29.960 | We as a podcast and I don't have any affiliation

01:38:32.800 | to any of these, but I will provide a links

01:38:35.080 | to a couple of the more prominent ones

01:38:36.580 | that are known to have 2% concentration of ketoconazole,

01:38:40.280 | as well as some other things in them

01:38:41.620 | known to offset some of that dryness and brittleness

01:38:43.800 | that ketoconazole shampoos can trigger.

01:38:46.840 | So by now I think it will be abundantly clear

01:38:49.640 | why inhibiting 5-alpha reductase and thereby reducing DHT

01:38:54.000 | should increase hair growth because of the negative impact

01:38:58.320 | that DHT has on the hair follicle.

01:39:01.040 | The major player in this whole story

01:39:04.400 | around inhibiting 5-alpha reductase and reducing DHT

01:39:08.120 | to maintain or increase hair growth

01:39:10.980 | is going to be finasteride

01:39:12.800 | and its close cousin, dutasteride.

01:39:15.200 | Finasteride is effective in reducing DHT

01:39:17.640 | because of its actions in reducing the type II isoenzyme

01:39:21.640 | or isoform of 5-alpha reductase.

01:39:24.480 | It turns out there's three different isoforms

01:39:26.500 | or what are sometimes called isoenzymes

01:39:28.280 | of 5-alpha reductase.

01:39:29.760 | This is getting pretty far down in the weeds.

01:39:32.000 | What I think most of you just need to know

01:39:33.520 | is that finasteride reduces DHT.

01:39:36.220 | That's the net product of finasteride.

01:39:38.640 | And in doing so, it can increase hair count

01:39:40.660 | by as much as 20%.

01:39:42.320 | Pretty remarkable if you think about it.

01:39:44.320 | In addition, finasteride treatment done properly,

01:39:47.880 | which we'll define in a moment,

01:39:50.020 | can reduce hair loss in 90% of all people that take it.

01:39:54.320 | That is, I mean, near staggering.

01:39:56.500 | I mean, there aren't many pharmaceuticals out there

01:39:58.160 | that have that kind of efficacy, really dramatic.

01:40:00.600 | And in addition, it's known to increase hair thickness

01:40:03.280 | by about 20 to 30% overall.

01:40:05.660 | So not just create new growth of hairs and thicker hairs,

01:40:09.600 | but whatever hair you do happen to have on your head,

01:40:11.580 | it can further thicken those.

01:40:13.480 | So the finasteride story is one,

01:40:16.480 | I think, of general success.

01:40:18.440 | I mean, it really seems to improve hair growth

01:40:20.840 | and help you hold on to the hair that you have.

01:40:23.620 | The issue with finasteride is twofold.

01:40:25.680 | First of all, it is known to have

01:40:27.640 | some pretty significant side effects

01:40:29.320 | if it's not dosed properly

01:40:31.000 | and in particular populations of people.

01:40:34.280 | And this is because there is a wide variation

01:40:37.480 | in the amount of the different isoenzymes that people make.

01:40:42.120 | This is why I brought up the isoenzymes earlier.

01:40:44.340 | Some people make more of isoenzyme one and three.

01:40:47.600 | Some people make more of isoenzyme two and three

01:40:51.240 | and every variation thereof.

01:40:53.400 | So when people take finasteride,

01:40:55.540 | some people are very strong responders

01:40:57.940 | and they achieve really effective hair regrowth

01:41:00.500 | and maintenance of hair.

01:41:01.800 | Other people, less effective,

01:41:03.240 | although still pretty impressive,

01:41:05.280 | but the catalog of side effects that people experience

01:41:08.080 | at a given dose varies widely.

01:41:10.000 | So there's a lot of trial and error that has to take place.

01:41:13.320 | I also should point out that finasteride

01:41:15.640 | comes in two major forms.

01:41:17.120 | There's an oral form and there's a topical form.

01:41:20.000 | So this is not unlike our discussion of minoxidil earlier.

01:41:23.000 | Topical finasteride is typically taken in 1% solution

01:41:28.580 | or ointment and rubbed into the head.

01:41:30.520 | Sometimes it's now also incorporated into shampoos,

01:41:32.840 | but typically it's put into a solution

01:41:35.720 | that people rub into their head.

01:41:37.360 | And it is thought that the 1% solutions are equivalent

01:41:40.740 | to one milligram of systemic finasteride.

01:41:44.040 | Now we need to take a step back and ask

01:41:45.520 | why was finasteride developed in the first place?

01:41:47.720 | Well, finasteride as a fairly potent

01:41:50.000 | 5-alpha reductase inhibitor, it's great at lowering DHT.

01:41:53.880 | It was developed for treatment of prostate enlargement

01:41:56.840 | and various issues of the prostate

01:41:58.640 | that are associated with elevated DHT that occurs with age.

01:42:01.560 | The topical finasterides were designed with the hope

01:42:04.400 | that the finasteride would make it into the hair follicle

01:42:07.580 | and would inhibit DHT there

01:42:09.600 | and allow for more growth of the hair,

01:42:11.000 | which apparently it does,

01:42:12.060 | but not make it into the systemic circulation,

01:42:14.140 | or at least not at concentration sufficient enough

01:42:16.120 | to cause as many side effects as with the oral dosing.

01:42:19.280 | Now, the problem is it does make it

01:42:21.400 | into systemic circulation.

01:42:23.880 | The issue is also that topical application of finasteride

01:42:27.440 | is harder to dose than oral finasteride.

01:42:31.000 | I'm not saying you should be taking oral

01:42:32.600 | rather than topical finasteride,

01:42:34.460 | but keep in mind that the dosages of finasteride

01:42:37.400 | that have been shown to be effective

01:42:38.720 | for inducing hair growth cover an enormous range.

01:42:41.640 | So as low as 0.01 milligrams per day

01:42:45.120 | and as high as five milligrams per day,

01:42:47.860 | which is a just staggering range.

01:42:51.120 | Now, when trying to simplify the problem

01:42:52.860 | of how much finasteride to take,

01:42:54.680 | either by way of oral tablet or by way of topical solution,

01:42:59.080 | we can get a bit of leverage on this

01:43:01.120 | by thinking about how much DHT reduction occurs

01:43:04.280 | as a function of dose.

01:43:05.620 | And there, finasteride shows us this really interesting,

01:43:08.800 | what's called logarithmic distribution.

01:43:11.360 | What it means is that for a dosage

01:43:13.720 | of 0.01 milligrams of finasteride,

01:43:17.000 | you're going to achieve approximately 50% reduction in DHT,

01:43:21.200 | and that's systemic DHT.

01:43:22.680 | So this is a blood draw measuring your DHT,

01:43:24.880 | then taking 0.01 milligrams of finasteride,

01:43:28.320 | again, 0.01, very low dose of finasteride,

01:43:32.360 | or appeared a couple of weeks,

01:43:33.720 | measure people's DHT in their blood again,

01:43:35.840 | and you see that it's reduced by 50%.

01:43:38.660 | However, at increasing dosages of 0.2 milligrams,

01:43:43.620 | one milligrams, five milligrams of oral finasteride per day

01:43:48.620 | over the same period of time, the increase,

01:43:52.760 | or I should say the reduction in dihydrotestosterone

01:43:55.740 | doesn't increase linearly.

01:43:57.180 | It's not that you go from 50% to 60% to 75% to 100%

01:44:01.400 | with each increasing dose, it tapers off,

01:44:03.800 | it kind of flattens out.

01:44:04.900 | It tends to increase a little bit,

01:44:06.100 | but it's sort of a gradual slope increasing

01:44:09.360 | as you head from 0.2 milligrams out to five milligrams.

01:44:12.880 | So what this means is that given that reducing DHT

01:44:17.380 | can cause various side effects, sexual side effects,

01:44:20.300 | reductions in either sexual function or sexual drive,

01:44:24.540 | as well as overall drive and motivation,

01:44:26.940 | sometimes even some depressive symptoms,

01:44:29.380 | that everything points to taking the lowest effective dose

01:44:33.860 | of finasteride and starting with a very low dose

01:44:36.540 | of finasteride because low doses of finasteride,

01:44:39.740 | even at that 0.01 milligrams taken orally daily,

01:44:44.180 | are already leading to a 50% reduction

01:44:47.240 | in dihydrotestosterone and thereby taken

01:44:49.780 | for a long enough period of time should offset hair loss

01:44:52.540 | and stimulate hair growth.

01:44:54.220 | One of the problems, however,

01:44:55.540 | is that people will start taking finasteride at a low dose,

01:44:58.460 | 0.1 milligrams or 0.2 milligrams, maybe even 0.01 milligrams

01:45:02.900 | and there will be a reduction in their DHT,

01:45:06.180 | but because of the long duration of that antigen phase,

01:45:09.780 | they don't see a lot of change in hair growth

01:45:12.100 | in the first month or even two months.

01:45:14.380 | And so what they end up doing is increasing their dosage

01:45:16.900 | and then they start to see hair growth,

01:45:18.260 | but then they start to experience more side effects.

01:45:21.380 | Now, the side effects of oral finasteride

01:45:23.140 | are serious enough and common enough in people

01:45:25.620 | that take finasteride that the topical solutions

01:45:27.960 | were developed, but there too, one needs to exercise caution

01:45:30.980 | because if we are going to translate

01:45:33.040 | between topical finasteride and oral finasteride

01:45:36.140 | with the understanding that topical finasteride

01:45:38.140 | can actually make it into the systemic circulation,

01:45:40.880 | we need to look at what's been shown in clinical studies,

01:45:43.380 | which is that, for instance, taking one milliliter

01:45:46.460 | of 0.25% finasteride applied to the scalp,

01:45:49.180 | this is a very typical recommendation,

01:45:51.780 | translates to the same thing that would be achieved

01:45:55.240 | with 2.5 milligrams of oral finasteride.

01:45:59.740 | And when I say translates to the same thing,

01:46:01.340 | what I mean is it leads to the same concentrations

01:46:03.740 | in the blood.

01:46:05.140 | Now, consider that 0.2 milligrams,

01:46:08.740 | 0.2 milligrams of finasteride in the blood

01:46:11.820 | is known to be effective in generating new hair growth

01:46:15.020 | and maintaining hair that one already has

01:46:17.360 | when they start the treatment.

01:46:18.860 | So if you think that the topical finasterides are actually

01:46:22.700 | creating lower overall systemic concentrations

01:46:26.360 | of finasteride, that is not necessarily the case.

01:46:29.200 | Again, one milliliter of topical finasteride at 0.25%

01:46:32.940 | leads to a 2.5 milligram concentration in the blood

01:46:37.240 | when the effective dose within the bloodstream

01:46:40.140 | by taking it orally as a pill is 0.2 milligrams.

01:46:44.420 | That might not seem like a big deal to you,

01:46:46.720 | although it is a big deal, right?

01:46:47.900 | We're talking 2.5 milligrams versus 0.2,

01:46:51.180 | but it is a huge deal when you consider

01:46:53.440 | that the side effects of finasteride increase

01:46:56.420 | as you increase the concentration of finasteride

01:46:58.540 | in the bloodstream.

01:46:59.980 | So where does this leave us?

01:47:01.580 | Should people who are interested in taking finasteride

01:47:04.420 | take the oral form at low dose or take the topical form

01:47:08.140 | and simply try and apply it less often

01:47:10.500 | or guess at what their systemic concentration

01:47:12.420 | of finasteride is?

01:47:13.640 | Well, it's going to vary from person to person.

01:47:15.400 | Some people are very sensitive to finasteride

01:47:17.660 | and not in the good sense.

01:47:18.960 | The side effects just really show up quickly

01:47:21.100 | and they tend to be dramatic.

01:47:22.260 | Other people, not so much.

01:47:24.160 | The dosage recommendations that I was able to arrive at

01:47:27.920 | based on the clinical studies and frankly,

01:47:30.480 | in discussion with some doctors who prescribe finasteride

01:47:34.260 | were the following.

01:47:35.540 | 0.5 milligrams to one milligram of finasteride

01:47:38.860 | as a tablet per day seems to be an effective

01:47:42.820 | and pretty safe starting place for most people.

01:47:46.060 | Now, some people will find that even that 0.5 milligram

01:47:48.420 | dosage is just going to cause side effects

01:47:50.120 | that are not going to work for them.

01:47:52.220 | And they're going to either have to reduce their dosage

01:47:54.780 | of finasteride or move to the topical

01:47:57.220 | or maybe cease taking finasteride altogether.

01:47:59.700 | But for many people out there,

01:48:01.420 | that's going to be pretty well tolerated.

01:48:03.940 | The key thing here is that one is going to have to wait

01:48:06.460 | some period of time to see

01:48:07.700 | whether or not any hair growth occurs.

01:48:09.540 | It is a naive and frankly, foolish approach

01:48:12.540 | based on what we know about the duration

01:48:14.380 | of that antigen phase of the hair

01:48:16.300 | to do one of these treatments, wait a week or two

01:48:19.180 | and then decide to up your dose.

01:48:20.820 | Now, it is not foolish to reduce your dose

01:48:22.940 | if you're experiencing bad side effects,

01:48:25.400 | but to simply increase your dose

01:48:26.980 | because you're not getting results quickly enough,

01:48:29.240 | that's not going to be the best approach.

01:48:30.740 | I really encourage people who are going to explore

01:48:32.940 | the finasteride route to think of this as a long-term

01:48:35.420 | project and to really ratchet up slowly, if at all,

01:48:38.740 | starting initially with a low dose

01:48:40.220 | taken for a long period of time,

01:48:41.380 | maybe even as long as 25 weeks

01:48:43.940 | before considering going up any further.

01:48:46.020 | Certainly, as I mentioned before,

01:48:47.320 | if you need to go down further,

01:48:49.340 | that's not going to be a problem,

01:48:51.140 | at least not in terms of reducing side effects.

01:48:53.860 | I mean, you're not going to get additional hair growth,

01:48:55.300 | but you're certainly not going to increase your side effects

01:48:57.900 | if you reduce your dose.

01:48:58.960 | However, I will talk a little bit later

01:49:00.480 | about post-finasteride syndrome,

01:49:02.220 | which is something that's getting

01:49:03.060 | increasing attention nowadays.

01:49:04.620 | That's something that occurs

01:49:05.620 | after people have taken finasteride

01:49:07.220 | for an extended period of time.

01:49:08.940 | Now, some of you have perhaps heard,

01:49:10.500 | and I'll just tell you right here,

01:49:11.860 | that the topical forms of finasteride

01:49:14.280 | are associated with far less side effects.

01:49:17.260 | Now, that might come as surprising

01:49:18.820 | given that topical application of finasteride

01:49:21.340 | can lead to systemic distribution of finasteride,

01:49:24.020 | but the numbers that are out there right now

01:49:26.180 | are that topical finasteride is associated

01:49:28.340 | with 30 to 50% fewer side effects

01:49:31.260 | or 30 to 50% less severe side effects

01:49:34.280 | than oral finasteride.

01:49:35.840 | Now, there are several things

01:49:37.040 | probably responsible for that.

01:49:38.380 | One is that people tend to ratchet up

01:49:40.000 | their dose of oral finasteride pretty quickly,

01:49:42.180 | but keep in mind that the effective dose of finasteride

01:49:44.820 | in the blood is 0.2 milligrams.

01:49:47.840 | Now, earlier I said the typical topical finasteride

01:49:50.440 | solutions are 0.25%.

01:49:52.780 | People are taking one mil of it.

01:49:53.880 | That equates to 2.5 milligrams,

01:49:55.940 | and so it seems like a massive overdosing.

01:49:58.360 | Ah, but here's the discrepancy,

01:50:00.280 | and here's where we can arrive

01:50:01.240 | at some reasonable recommendations.

01:50:03.480 | If you decide that finasteride's right for you,

01:50:06.880 | you get a prescription,

01:50:08.560 | I would hope that you're monitoring your DHT levels

01:50:10.740 | and other hormone levels.

01:50:11.840 | That would be ideal in working with a doctor, please.

01:50:14.620 | 0.5 milligrams to one milligram per day

01:50:19.080 | of oral finasteride seems to be the best starting place.

01:50:22.700 | For topical finasteride,

01:50:26.520 | it's going to be that one milliliter of 0.25%

01:50:31.020 | that we talked about earlier,

01:50:32.240 | but that's taken only one time per week.

01:50:34.460 | And you can fully expect that right after the application,

01:50:36.680 | you will have higher levels of finasteride

01:50:38.960 | in your bloodstream and therefore lower levels of DHT,

01:50:41.680 | and that that will alter across the week.

01:50:44.480 | Most people are not going to be able to measure their DHT

01:50:47.100 | on a day-by-day or even weekly basis.

01:50:49.000 | It's just too expensive and labor intensive,

01:50:51.760 | but I think those dosing regimens ought to get people

01:50:54.000 | into more or less the same category

01:50:55.800 | of optimizing hair maintenance and hair growth

01:50:58.860 | while minimizing finasteride side effects.

01:51:01.280 | One point about finasteride taken either alone

01:51:04.400 | or in combination is that in recent years,

01:51:07.600 | really in the last five or so years,

01:51:10.100 | there's been increasing discussion

01:51:12.040 | about so-called post-finasteride syndrome.

01:51:15.200 | Now, post-finasteride syndrome is indeed a new phenomenon

01:51:18.940 | in the sense that finasteride has been prescribed

01:51:21.500 | for a very long period of time

01:51:23.700 | for treatment of the prostate

01:51:25.080 | at dosages of about five milligrams per day, right?

01:51:28.440 | That's a very high dose, sometimes lower,

01:51:31.160 | but as high as five milligrams per day.

01:51:33.600 | And for many years, there was no discussion

01:51:35.800 | about this post-finasteride syndrome.

01:51:37.640 | What is post-finasteride syndrome?

01:51:39.160 | Post-finasteride syndrome is when typically it's males,

01:51:42.760 | this is where it's been described,

01:51:44.360 | will take finasteride at any range of dosages

01:51:47.680 | from one milligram to five milligrams per day.

01:51:50.280 | They're either doing this for prostate

01:51:52.160 | or more likely they're doing it to offset hair loss

01:51:54.520 | and increase hair growth.

01:51:56.160 | And then they stop taking finasteride for whatever reason,

01:51:58.700 | financial, or it wasn't working for them,

01:52:00.400 | or the side effects were not to their liking.

01:52:03.360 | And they start to experience some very severe,

01:52:06.240 | what can only be called syndrome effects,

01:52:09.160 | such as very reduced libido,

01:52:12.200 | very reduced erectile function,

01:52:15.240 | very reduced mood to the point of depression,

01:52:17.960 | even suicidal depression.

01:52:19.600 | So this is pretty scary stuff,

01:52:21.120 | especially since it's occurring at an age

01:52:23.260 | when most of these things

01:52:24.380 | are not typically occurring in males.

01:52:26.300 | They can occur, but they're not typical of younger males

01:52:29.020 | in their 20s and 30s and early 40s.

01:52:31.500 | So we have to ask ourselves, what's going on here?

01:52:33.240 | After all, people have taken finasteride for the prostate

01:52:36.120 | at fairly high dosages

01:52:37.140 | without this post-finasteride syndrome when they've stopped.

01:52:40.040 | Now these young males are taking finasteride,

01:52:42.120 | they're coming off finasteride,

01:52:43.080 | and they're getting this very severe,

01:52:44.880 | very debilitating post-finasteride syndrome.

01:52:47.320 | This has become a kind of hot topic,

01:52:49.200 | enough so that medical doctors

01:52:50.800 | who have been prescribing finasteride for a very long time

01:52:53.320 | have been forced to address this.

01:52:54.820 | I think at first they were sort of perplexed and thought,

01:52:56.940 | I don't know, this might be psychosomatic,

01:52:58.680 | whatever that means.

01:52:59.520 | I mean, as a neuroscientist

01:53:00.560 | who works on mind-body connection,

01:53:01.740 | we know that nothing is truly psychosomatic.

01:53:04.260 | Everything is of the mind and body.

01:53:06.580 | But the point is that enough medical attention

01:53:09.100 | has been placed on post-finasteride syndrome

01:53:10.980 | and trying to unravel exactly what that is,

01:53:14.120 | where there are now a few general conclusions

01:53:17.160 | about what might be going on.

01:53:18.440 | First of all, it seems that younger males taking finasteride,

01:53:22.580 | in particular at high dosages to improve hair growth

01:53:25.440 | or offset hair loss, seems to be one of the key variables.

01:53:28.780 | We're not seeing this post-finasteride syndrome

01:53:31.460 | as much in older males.

01:53:32.960 | In fact, it seems to occur more in males in their 20s

01:53:36.480 | and 30s than males in their 40s and older.

01:53:39.200 | So that's one thing.

01:53:40.040 | And it may relate to the ways in which dihydrotestosterone

01:53:43.040 | we know has a very key role in early embryonic development.

01:53:47.180 | It's actually what's responsible for the male genitalia.

01:53:50.120 | It's also responsible for certain things

01:53:51.800 | in female development, but mainly in utero,

01:53:54.120 | it's responsible for male development

01:53:55.960 | and development of the penis in particular.

01:53:57.560 | And then around the time of puberty, dihydrotestosterone

01:54:01.520 | acts again in what's called its activating effects

01:54:05.540 | to further increase growth of the genitalia,

01:54:08.640 | increase the musculature, bone growth, et cetera,

01:54:11.080 | and increase libido and a number of other things.

01:54:13.200 | It's probably also involved in the activation of puberty.

01:54:16.020 | It's certainly not the only hormone involved

01:54:18.420 | in the activation of male puberty,

01:54:19.740 | but it's certainly one of the key players.

01:54:21.580 | So dihydrotestosterone has these known early roles

01:54:24.620 | in embryonic development and in puberty.

01:54:27.580 | But what post-phenasteride syndrome seems to indicate

01:54:30.220 | is that dihydrotestosterone is likely having further effects

01:54:34.220 | on male maturation, in particular maturation

01:54:36.980 | of the hypothalamus and areas of the brain

01:54:39.200 | that continue well into one's 20s

01:54:41.740 | and maybe even one's 30s.

01:54:43.300 | And here, I just want everyone to keep in mind

01:54:45.660 | that we tend to think about development as childhood,

01:54:49.780 | teenage years, young adulthood, adulthood,

01:54:52.720 | but really development never stops.

01:54:54.360 | Development is something that starts at conception

01:54:56.500 | and birth, of course, and then extends all the way out

01:54:59.500 | until the point when we die.

01:55:00.500 | So even if we live to be in our late 90s

01:55:02.780 | or achieve 100 years of age,

01:55:04.500 | development is occurring that entire time

01:55:06.700 | and these different hormones such as dihydrotestosterone

01:55:09.260 | are having different impact across the lifespan

01:55:12.580 | and in different ways across the lifespan.

01:55:15.080 | So there isn't a clear conclusion

01:55:16.860 | about what post-phenasteride syndrome is really all about,

01:55:19.880 | but it points to the fact that DHT is likely to be involved

01:55:23.100 | in development of the brain and the brain to genital axis,

01:55:27.700 | because I mentioned that because so many of the side effects

01:55:30.300 | that are associated with this post-phenasteride syndrome

01:55:32.340 | seem to center on sexual side effects,

01:55:34.860 | although they're also the depressive side effects.

01:55:36.580 | Of course, those can be related to one another

01:55:38.440 | in either direction.

01:55:39.660 | So while I do understand that loss of one's hair

01:55:42.540 | or potential loss of one's hair

01:55:44.480 | can be particularly troubling and anxiety provoking,

01:55:47.520 | even cause depression in some cases, I am sensitive to that.

01:55:50.740 | You also want to be sensitive to the fact

01:55:52.580 | that some of these treatments such as finasteride

01:55:54.960 | can carry very serious side effects,

01:55:56.780 | even if you come off them, AKA post-phenasteride syndrome.

01:56:00.940 | As long as we're talking about finasteride

01:56:02.620 | and this general pathway of 5-alpha reductase inhibition

01:56:05.580 | and thereby DHT inhibition and on and on,

01:56:08.320 | topics and themes and nomenclature you are now

01:56:11.340 | very familiar with, we have to talk about dutasteride.

01:56:15.040 | Dutasteride is yet another molecule similar to finasteride,

01:56:19.780 | but remember those three isoforms

01:56:21.620 | of the 5-alpha reductase enzyme?

01:56:23.860 | Well, it inhibits all three, mainly type one and type two,

01:56:27.460 | but also type three, and it does it very potently.

01:56:31.000 | So as a consequence, the typical dosage of oral dutasteride,

01:56:35.700 | get this, 0.5 milligrams to 2.5 milligrams taken orally,

01:56:40.240 | works two to five times faster than typical finasteride

01:56:44.900 | at inducing hair regrowth and reduces DHT by, get this,

01:56:50.680 | 95%, so it just near flatlines DHT.

01:56:55.320 | And that can occur at concentrations as low as 0.5 milligrams,

01:56:58.800 | although you will see prescriptions

01:57:00.400 | and people taking dutasteride anywhere from 0.5 milligrams

01:57:03.940 | all the way to 2.5 milligrams orally.

01:57:06.360 | Now, not surprisingly, dutasteride is associated

01:57:08.900 | with a lot of side effects related to the DHT pathway.

01:57:12.240 | So things like reduction in sex drive,

01:57:14.360 | reduction in overall drive.

01:57:17.480 | It also tends to impact other hormone pathways,

01:57:19.940 | so increases in estrogen prolactin.

01:57:21.760 | That's why gynecomastia,

01:57:23.520 | growth of male breast tissue sometimes occurs

01:57:25.660 | when people take dutasteride.

01:57:27.240 | And so you're probably asking,

01:57:28.580 | why would anyone take dutasteride?

01:57:30.280 | Why not just take finasteride and wait for that hair growth?

01:57:33.500 | Well, the answer is that people are often very impatient

01:57:37.160 | and it turns out that dutasteride

01:57:39.160 | works about two to five times faster than finasteride.

01:57:42.520 | So some people don't want to wait a full 30 weeks

01:57:45.520 | or 40 weeks or 50 weeks or more

01:57:47.520 | in order to grow their hair back.

01:57:49.020 | And they're very concerned about the hair loss

01:57:50.520 | that's occurring.

01:57:51.360 | So they will take what I hope would be a very low dose

01:57:54.620 | of dutasteride.

01:57:56.680 | I realize that there are ways to take dutasteride

01:57:59.100 | that can be safer, offset some of these side effects,

01:58:02.320 | but by my read of the literature,

01:58:04.740 | if one is going to try to mildly inhibit the DHT pathway,

01:58:08.380 | things like salt palmetto, things like topical caffeine,

01:58:12.020 | which has some effect on the androgen pathway,

01:58:14.160 | but as we talked about earlier, tickles other pathways,

01:58:17.140 | things like ketoconazole,

01:58:19.100 | mild reduction in androgen receptor pathways in the follicle

01:58:22.400 | and very direct because it's applied directly to the scalp.

01:58:24.580 | Things like that are going to be the best route

01:58:26.460 | for mild reductions in DHT

01:58:28.840 | as an attempt to maintain hair or grow hair.

01:58:31.620 | Whereas if one really wants a potent stimulus

01:58:33.900 | for increasing hair growth,

01:58:36.020 | that's very likely going to be finasteride

01:58:38.760 | and hopefully low enough dosages of finasteride

01:58:41.680 | and hopefully a patient enough, patient, person,

01:58:45.120 | that they are willing to wait the duration of time

01:58:48.220 | required for that hair growth to come back

01:58:50.500 | because they understand that that androgen phase

01:58:52.640 | takes some time.

01:58:53.740 | Now, the holy grail of all this hair stuff

01:58:55.520 | is in understanding that no one specific treatment is magic.

01:58:59.540 | And in fact, there are now a number of good meta-analyses

01:59:02.640 | comparing the various treatments we've talked about today

01:59:05.500 | alone or in combination.

01:59:06.880 | And we can summarize that pretty easily

01:59:08.720 | by saying that combination treatments

01:59:11.380 | that involve a mechanical stimulus

01:59:14.100 | and a chemical stimulus

01:59:15.760 | are always going to be better than either one alone.

01:59:18.160 | And within the mechanical category,

01:59:19.940 | the stimulus that seems to work best is microneedling.

01:59:23.460 | So the combination of microneedling and finasteride

01:59:26.420 | can lead to some pretty robust and impressive hair regrowth.

01:59:29.840 | So much so that people that were,

01:59:31.740 | I guess we'd only describe them as pretty bald or bald,

01:59:34.840 | can regrow significant amounts of hair.

01:59:37.100 | I've never seen examples of people who were completely bald,

01:59:40.380 | meaning lacking all scalp hair

01:59:42.200 | to grow back a full head of hair.

01:59:43.900 | But the combination of microneedling and finasteride

01:59:46.740 | is probably the most effective way to go.

01:59:48.940 | And if you're going to do that,

01:59:50.160 | there's no reason why you couldn't also use

01:59:52.020 | ketoconazole shampoo, couldn't also use salt palmetto.

01:59:55.580 | There's no reason to think that these things

01:59:56.860 | collide with one another.

01:59:58.080 | Although anytime you're inhibiting a DHT pathway

02:00:00.660 | or whether or not you're increasing or decreasing

02:00:03.020 | any hormone pathway for that matter,

02:00:04.820 | you want to be careful about layering

02:00:06.220 | in too many different treatments

02:00:07.600 | because you don't want your DHT level to go too low.

02:00:10.060 | I mean, let's keep in mind that

02:00:11.500 | even if you take a very low dose of finasteride

02:00:13.600 | and reduce your DHT and don't have side effects,

02:00:15.900 | maybe just the mere addition of salt palmetto,

02:00:17.920 | which leads to a slight reduction in DHT

02:00:21.380 | combined with some caffeine ointment

02:00:23.080 | would be sufficient enough to start inducing

02:00:24.720 | some of the low DHT associated side effects.

02:00:27.500 | So you really have to see for you.

02:00:29.340 | And that's one of the major issues in this whole field

02:00:31.800 | of hair growth and regrowth

02:00:33.580 | is that people are highly individual in their response

02:00:37.140 | and in their side effect profile to these various treatments.

02:00:39.940 | But there's an enormous range there.

02:00:41.120 | And unfortunately, there's no way to know a priori

02:00:44.560 | before doing these treatments,

02:00:45.960 | what your response is going to be in terms of side effects.

02:00:48.760 | So you're simply going to have to explore.

02:00:50.220 | And I would hope that you would explore

02:00:51.380 | starting with minimal possible effective dosages

02:00:54.700 | and to do that in coordination with a medical professional.

02:00:56.960 | So you could really evaluate these things

02:00:58.420 | at the level of blood and cosmetic changes.

02:01:01.140 | And in fact, that's a pretty good motivator

02:01:03.060 | for thinking about the different treatments

02:01:04.480 | that we talked about today.

02:01:05.860 | Everything from mechanical treatments,

02:01:08.280 | as simple as massage, which we've all heard about,

02:01:10.500 | but for which there really aren't a lot of data

02:01:12.700 | for supporting hair growth.

02:01:13.700 | But certainly things like microneedling,

02:01:16.120 | which is a mechanical stimulus

02:01:17.740 | for which there are pretty good data

02:01:19.580 | that it can improve hair growth.

02:01:21.540 | Also things like Saul Palmetto, a weak DHT antagonist.

02:01:26.000 | Also things like ketoconazole shampoo,

02:01:27.980 | which again is a weak DHT antagonist

02:01:30.660 | and operates through some other pathways as well

02:01:33.080 | to stimulate hair growth.

02:01:34.300 | My suggestion is that anyone, young, old, male, female,

02:01:37.860 | who's thinking about embarking on various treatments

02:01:40.400 | for offsetting hair loss and stimulating hair growth,

02:01:43.140 | consider both mechanical approaches

02:01:45.040 | and the approaches that attack the chemical pathways

02:01:48.120 | that can stimulate hair growth

02:01:49.820 | and can inhibit the inhibitors of hair growth.

02:01:53.460 | In fact, that's the reason why we spend so much time

02:01:55.500 | on the biology of hair growth

02:01:57.160 | and what shuts down hair growth early on in today's episode.

02:02:01.080 | And then systematically went through

02:02:03.180 | each of the various treatments that relies on,

02:02:05.900 | and in some cases hinges entirely on,

02:02:08.040 | either a mechanical stimulus or a chemical stimulus

02:02:11.060 | in order to exert its effects.

02:02:12.880 | My goal today was not to overwhelm you

02:02:14.540 | with a ton of biology about hair,

02:02:16.780 | although we did cover a lot of biology

02:02:18.480 | of hair and stem cells and hair growth.

02:02:20.820 | My goal in describing all that was really for you

02:02:23.060 | to be able to hear about various treatments,

02:02:25.460 | whether or not it's lasers or PRP or finasteride,

02:02:28.420 | dutasteride, or whatever is coming next

02:02:30.980 | that we're sure to hear about soon online

02:02:33.340 | and from the medical community,

02:02:34.580 | and to be able to place those into bins

02:02:37.160 | related to their known or potential mechanisms,

02:02:40.020 | and then to be able to step back and evaluate

02:02:42.760 | which, if any, of those treatments might be right for you.

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02:04:29.980 | Thank you for joining me for today's discussion.

02:04:31.740 | All about the biology of hair and hair growth,

02:04:34.400 | how to hold onto the hair you have,

02:04:36.220 | and to stimulate new hair growth.

02:04:38.660 | And last, but certainly not least,

02:04:40.900 | thank you for your interest in science.

02:04:42.620 | [upbeat music]

02:04:45.200 | (upbeat music)

The Science of Healthy Hair, Hair Loss and How to Regrow Hair | Huberman Lab Podcast

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