The Science of How to Optimize Testosterone & Estrogen

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

00:00:02.280 | where we discuss science and science-based tools

00:00:04.920 | for everyday life.

00:00:05.920 | I'm Andrew Huberman, and I'm a professor of neurobiology

00:00:12.160 | and ophthalmology at Stanford School of Medicine.

00:00:15.320 | This podcast is separate from my teaching

00:00:17.160 | and research roles at Stanford.

00:00:18.980 | It is, however, part of my desire and effort

00:00:21.020 | to bring zero cost to consumer information

00:00:23.100 | about science and science-related tools

00:00:25.100 | to the general public.

00:00:26.940 | Before we begin today, just want to acknowledge

00:00:29.160 | that if you're watching this on YouTube,

00:00:30.840 | yes, I have a bandage on the left side of my face.

00:00:33.840 | I was trying to cook something for Costello and I,

00:00:36.200 | and I got burned, burned myself.

00:00:38.260 | It was a cooking accident.

00:00:39.300 | I'm fine, no need to dwell on it, we can move on.

00:00:41.880 | But I just wanted to let you know,

00:00:43.000 | everybody's going to be okay.

00:00:44.000 | He got a great meal, I got a burn and a great meal.

00:00:47.480 | Today's episode is brought to us by Four Sigmatic.

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00:01:06.160 | I started using Four Sigmatic coffee a few years ago,

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00:04:26.380 | Theragun is a handheld percussive therapy device

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00:04:31.520 | I was introduced to Theragun on a dive expedition

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00:05:49.160 | This month on the Huberman Lab Podcast,

00:05:51.040 | we're talking all about hormones,

00:05:52.920 | these incredible chemicals that can impact our mood,

00:05:56.280 | our behavior, our feelings of optimism or pessimism.

00:06:00.160 | The amazing thing about hormones

00:06:01.700 | is that hormones impact all those things,

00:06:04.480 | but all those things, how we feel and what we do

00:06:07.000 | and what we think also can impact our hormones.

00:06:09.800 | And so it's a really fascinating area of biology

00:06:12.280 | that impacts every single one of us every day,

00:06:15.080 | both in wakefulness and in sleep and throughout the lifespan.

00:06:19.040 | Today, we're going to be talking about hormone optimization,

00:06:21.880 | and we're mainly going to be focusing on estrogen

00:06:24.600 | and testosterone and their derivatives.

00:06:27.000 | Last episode of the Huberman Lab Podcast,

00:06:29.480 | we talked about sexual development.

00:06:31.580 | That is how the chromosomes, the gonads and hormones

00:06:35.800 | impact what we call sexual development,

00:06:38.000 | leading all the way up to puberty.

00:06:39.880 | Today, we're mainly going to talk about processes

00:06:42.400 | that happen from puberty onward.

00:06:44.420 | Although we might talk a little bit

00:06:45.600 | about development as well.

00:06:47.000 | So today, we're going to talk a lot about basic biology,

00:06:49.900 | but we're going to weave in a lot of practical tools

00:06:52.560 | along the way for how to optimize

00:06:54.440 | these incredibly powerful things that we call hormones.

00:06:57.720 | Before we dive into our discussion

00:06:59.240 | about hormone optimization,

00:07:01.060 | I want to raise what I think is a very important point

00:07:03.520 | that at least I hadn't heard of until recently,

00:07:06.600 | which is the concept of salutogenesis.

00:07:09.580 | Many of us are familiar with the concept of pathogenesis,

00:07:12.760 | the idea that there are all these scary diseases

00:07:14.940 | like dementia and heart disease and stroke

00:07:18.040 | and all these things that await us

00:07:19.820 | if we don't take good care of ourselves

00:07:21.480 | and that might await us even if we do.

00:07:24.320 | That's the pathogenic model.

00:07:26.200 | Salutogenesis is something I learned about

00:07:28.100 | from one of my Stanford Medicine colleagues,

00:07:30.240 | which is a different orientation toward health and wellbeing

00:07:32.760 | where you're taking on particular behaviors,

00:07:35.520 | you're taking on a particular stance towards nutrition

00:07:38.360 | and exercise, supplementation, et cetera,

00:07:40.780 | in order to promote wellbeing above where you would be

00:07:44.300 | if you were not doing those behaviors.

00:07:46.640 | If you think about these two things,

00:07:48.460 | salutogenesis and the pathogenic model

00:07:50.820 | are really two sides of the same coin,

00:07:53.200 | but I'll just give an example

00:07:54.700 | of how this might affect you in a real way.

00:07:57.580 | If you like exercise because it feels good, great,

00:08:01.200 | but many people exercise or eat well for that matter

00:08:04.760 | in order to avoid heart disease or to avoid dementia,

00:08:08.220 | to avoid negative changes in body composition.

00:08:12.420 | And while that's powerful and certainly is the case,

00:08:15.220 | that exercise will help you move away from all those things,

00:08:18.100 | the salutogenesis model differs in that

00:08:20.920 | it involves a mindset and an orientation

00:08:22.760 | towards doing those things in order to feel good,

00:08:25.320 | in order to enhance your level of energy,

00:08:27.240 | in order to improve endocrine function

00:08:29.360 | and metabolic function.

00:08:30.900 | So it's really part of the pathogenic model

00:08:33.800 | and yet salutogenesis is really more of a mindset

00:08:36.420 | toward why you would do these particular behaviors.

00:08:38.740 | And really the most powerful mindset is going to be one

00:08:41.180 | where you are thinking about the pathogenic model,

00:08:43.820 | doing things so that you don't end up sick, et cetera,

00:08:46.660 | and to move away from sickness,

00:08:48.340 | as well as the salutogenic model

00:08:50.420 | where you're doing things

00:08:51.260 | in order to move towards health and wellbeing.

00:08:53.740 | We think of health and wellness nowadays

00:08:55.700 | or the wellness community or wellness practices,

00:08:58.700 | and in many ways that is the essence

00:09:01.300 | of the salutogenic model,

00:09:02.900 | but I found it very interesting to know

00:09:04.600 | that within the field of allopathic medicine,

00:09:06.820 | these two models exist,

00:09:07.880 | but we don't hear about the salutogenic model

00:09:09.860 | quite as often.

00:09:11.020 | So it's just something to keep in mind,

00:09:12.300 | especially because of some of the mindset effects

00:09:14.440 | that were discussed in previous episodes.

00:09:16.760 | I'm not going to go into these in detail again right now,

00:09:19.500 | but if you might recall from the episode on food and mood,

00:09:23.240 | we talked about some of these incredible studies

00:09:25.140 | that were done by Alia Crum's group at Stanford and others,

00:09:28.180 | showing that if you tell people

00:09:30.600 | that the behavior that they're about to do,

00:09:32.800 | in this case, it was people cleaning up hotel rooms

00:09:35.180 | 'cause that was their job.

00:09:36.340 | If you tell them that it's good for them,

00:09:38.400 | then you see much greater positive health effects

00:09:41.420 | than if they aren't aware of that information,

00:09:43.620 | that it's good for them.

00:09:44.660 | So we should really be thinking about

00:09:46.640 | not just moving away from disease and negative things,

00:09:49.100 | but also why certain things are good for us,

00:09:51.700 | because it's well-established now

00:09:53.540 | from really good scientific studies

00:09:55.660 | that keeping in mind the positive effects of things

00:09:58.440 | can really have an outsized effect on wellbeing

00:10:01.900 | right down to the level of our physiology.

00:10:04.980 | So let's talk about hormone optimization.

00:10:07.660 | Today, we're going to talk about hormone optimization

00:10:10.540 | in reference to estrogen and testosterone

00:10:13.340 | and their derivatives.

00:10:14.920 | Now, estrogen and testosterone and their derivatives

00:10:17.680 | are what we call sex steroids.

00:10:20.140 | Now, the sex steroids immediately call to mind sex,

00:10:24.580 | for obvious reasons, and steroids,

00:10:27.060 | meaning anabolic steroids.

00:10:28.740 | But I just want to emphasize that estrogen and testosterone

00:10:31.780 | are present in everybody.

00:10:33.500 | It's their ratios that determine their effects.

00:10:36.460 | So today, we're going to talk about

00:10:37.700 | how you can optimize their ratios

00:10:39.340 | depending on your particular life goals,

00:10:41.860 | because the ratio of estrogen and testosterone

00:10:44.720 | in every individual has profound influence

00:10:48.100 | on feelings of wellbeing, feelings of optimism,

00:10:52.260 | feelings of anxiety or lack of anxiety,

00:10:55.260 | on reproduction, on sexual behavior,

00:10:57.980 | independent of reproduction.

00:11:00.020 | They are profoundly powerful molecules,

00:11:03.220 | and we all make these molecules to some degree or another,

00:11:06.860 | but there are also important behavioral tools,

00:11:09.860 | supplementation tools, as well as prescription drugs

00:11:13.420 | that can impact the ratios of testosterone and estrogen

00:11:16.580 | in really powerful ways.

00:11:18.180 | So we're going to cover all of that.

00:11:20.340 | I want to emphasize that when you hear sex steroids

00:11:24.120 | or steroid hormones,

00:11:25.580 | most people think about anabolic steroids.

00:11:28.220 | And of course, anabolic steroids

00:11:30.540 | are derivatives of testosterone or testosterone itself,

00:11:34.860 | and they are heavily used and abused in the sports community

00:11:38.220 | as well as outside the sports community.

00:11:40.280 | But there of course are many steroids

00:11:42.260 | that are not anabolic steroids

00:11:43.700 | that are also abused in sports.

00:11:45.220 | Today, we're not talking about drugs and sports,

00:11:47.500 | but I think that it carries such a heavy weight

00:11:49.860 | when people hear the word steroids,

00:11:51.340 | they think about anabolic steroids.

00:11:54.020 | So while today's discussion will certainly be relevant

00:11:56.420 | to physical performance,

00:11:57.300 | in fact, we're going to talk about

00:11:58.300 | how specific types of exercise,

00:12:00.540 | particular patterns of cold exposure,

00:12:02.780 | as well as particular patterns,

00:12:04.260 | believe it or not, of breathing,

00:12:05.900 | can impact sex steroid hormones,

00:12:08.920 | both estrogen and testosterone.

00:12:11.100 | The discussion isn't really geared

00:12:12.620 | towards performance enhancement in sport,

00:12:14.560 | although we will do an entire episode,

00:12:16.580 | perhaps even an entire month

00:12:17.860 | related to performance enhancement in physical enterprises.

00:12:21.420 | So one of the first things to understand

00:12:23.340 | if you want to optimize your hormones

00:12:25.520 | is where they come from.

00:12:27.300 | There are a lot of different glands in the body

00:12:29.060 | that produce hormones.

00:12:30.060 | There's the pineal gland.

00:12:31.940 | Some hormones are made in the hypothalamus.

00:12:34.620 | Hormones are made by the gonads,

00:12:36.340 | the ovaries or the testes.

00:12:38.600 | You've got the thyroid gland.

00:12:40.380 | There are a bunch of different glands

00:12:41.580 | that make these different hormones,

00:12:43.100 | but when we're talking about the sex steroid hormones,

00:12:45.100 | estrogen and testosterone,

00:12:46.460 | the major sources are ovaries for estrogen

00:12:49.700 | and the testes for testosterone,

00:12:51.300 | although the adrenals can also make testosterone.

00:12:55.080 | Now, there are also some enzymes.

00:12:57.380 | Enzymes are things that can change chemical composition,

00:13:01.740 | and the enzymes that we're going to talk about today

00:13:03.780 | are the aromatases mainly.

00:13:05.900 | The aromatases convert testosterone into estrogen.

00:13:09.440 | So in a male, for instance, that has very high testosterone,

00:13:13.300 | some of that is going to be converted

00:13:15.100 | into estrogen by aromatase,

00:13:16.660 | and aromatase is made by body fat.

00:13:18.760 | It's also made in the testes themselves.

00:13:21.100 | A lot of people don't realize this,

00:13:22.200 | but the testes actually have the capacity

00:13:24.240 | to manufacture estrogen and aromatase, albeit at low levels,

00:13:28.500 | but this turns out to be important

00:13:30.180 | for optimizing hormone levels in males at later points,

00:13:34.900 | and we'll discuss that.

00:13:36.300 | It's important to note that there's a huge range

00:13:38.260 | in terms of the levels of hormones,

00:13:40.100 | testosterone and estrogen, between individuals,

00:13:43.500 | and it actually occurs

00:13:45.100 | within individuals across the lifespan.

00:13:47.100 | I'm not going to throw out specific numbers

00:13:48.780 | of X picograms per deciliter, et cetera, today,

00:13:51.580 | because that's going to vary a lot.

00:13:53.540 | It's going to depend on whether or not

00:13:54.500 | you're measuring in picograms or nanograms

00:13:56.480 | and that sort of thing.

00:13:57.320 | If you want to examine your hormones,

00:13:58.860 | you should do that in conjunction with a medical doctor,

00:14:02.020 | ideally an endocrinologist,

00:14:03.260 | can help you sort out that information,

00:14:05.160 | but the important thing to know

00:14:07.040 | is that prepubescent females make very little estrogen,

00:14:10.660 | and when we talk about estrogen,

00:14:11.660 | we mainly talk about estradiol,

00:14:13.320 | which is the most active form of estrogen

00:14:15.520 | in both males and females.

00:14:17.320 | So prepubescent females, very low levels of estrogen.

00:14:20.860 | During puberty, levels of estrogen,

00:14:23.740 | AKA estradiol, basically skyrocket,

00:14:26.740 | and then across the lifespan,

00:14:29.220 | estrogen is going to vary

00:14:30.380 | depending on the stage of the menstrual cycle,

00:14:32.320 | but as one heads into menopause,

00:14:34.180 | which typically takes place nowadays,

00:14:36.060 | somewhere between age 45 and 60,

00:14:38.800 | levels of estrogen are going to drop,

00:14:40.300 | and then post-menopause levels of estrogen are very low.

00:14:43.100 | As well, testosterone will fluctuate across the lifespan.

00:14:46.840 | Testosterone is going to be relatively low pre-puberty,

00:14:50.580 | in males during puberty, it's going to skyrocket,

00:14:53.860 | and then the current numbers are that it drops off

00:14:57.160 | at about a rate of 1% per year,

00:14:59.380 | although we're going to talk about some data

00:15:00.980 | that show that there's actually

00:15:01.900 | tremendous variation in testosterone levels.

00:15:04.420 | There's actually a lot of examples of men in their 90s,

00:15:08.020 | their 90s, who still have testosterone levels

00:15:10.540 | that mimic pubertal levels, which is remarkable,

00:15:13.300 | and speaks to the huge variation in testosterone levels

00:15:15.780 | across individuals.

00:15:17.540 | So let's talk about other sources of these hormones,

00:15:20.900 | and then it will make clear what avenues

00:15:24.260 | you might want to take in order to optimize these hormones.

00:15:27.540 | The other glands and tissues in the body

00:15:29.680 | that make these hormones, testosterone and estrogen,

00:15:32.620 | as I mentioned briefly, are the adrenals,

00:15:34.860 | so the adrenals right up top the kidneys,

00:15:37.140 | and the release of these steroid hormones from the adrenals,

00:15:41.180 | in particular testosterone

00:15:42.480 | and some of its related derivatives,

00:15:45.280 | are mainly activated by competition.

00:15:48.860 | So let's talk about competition,

00:15:50.900 | because it turns out that competition

00:15:53.480 | is a powerful influence on the sex steroid hormones,

00:15:57.960 | and the sex steroid hormones

00:15:59.280 | powerfully influence competition.

00:16:02.160 | So most people don't realize this,

00:16:03.760 | but most males of a given mammalian species

00:16:07.560 | never get to reproduce.

00:16:08.840 | In fact, they never even get to have sex at all.

00:16:11.900 | And we don't often think about that,

00:16:13.560 | but testosterone plays a powerful role

00:16:16.900 | in determining which members of a given species

00:16:19.340 | will get to reproduce,

00:16:20.640 | which ones of that species

00:16:22.800 | will actually get access to females.

00:16:25.320 | And so here I'm not talking about humans specifically,

00:16:28.600 | but it's well-known in species like elephant seals,

00:16:33.160 | in species like antlered animals and rams, for instance,

00:16:37.980 | that the higher levels of testosterone

00:16:39.800 | correlate with access to females.

00:16:42.280 | Now, one interpretation of this

00:16:44.440 | is that the females are detecting

00:16:46.720 | which males have high testosterone and selecting them.

00:16:49.320 | They're more receptive to them.

00:16:50.540 | We're going to talk about receptivity

00:16:52.520 | for mating in a moment.

00:16:54.840 | But it's actually more so

00:16:57.840 | that the males that have higher testosterone

00:17:00.400 | forage further and will fight harder for the females.

00:17:05.160 | And this is really interesting

00:17:06.400 | because there's very good evidence now

00:17:08.360 | that testosterone can reduce anxiety,

00:17:11.920 | promote novelty seeking,

00:17:13.840 | and promote competitive interactions.

00:17:17.240 | And so before you leap too far with this in your mind

00:17:19.640 | and think about all these human behaviors,

00:17:21.480 | just stay with me

00:17:22.320 | 'cause there's a little bit of biology here

00:17:23.560 | that makes it all make sense.

00:17:24.880 | And it turns out to be pretty simple.

00:17:27.100 | We have a brain region called the amygdala.

00:17:31.120 | In Latin, that just means almond.

00:17:32.540 | But the amygdala is most famous for its role in fear.

00:17:35.080 | We hear a lot about fear and the amygdala.

00:17:37.640 | But the amygdala is really involved in threat detection.

00:17:40.700 | It sets our thresholds for anxiety

00:17:43.420 | and what we consider scary or too much.

00:17:46.920 | Testosterone, secreted from the gonads

00:17:49.560 | and elsewhere in the body,

00:17:50.860 | binds to the amygdala

00:17:52.840 | and changes the threshold for stress.

00:17:55.660 | So I've said before on previous versions of this podcast

00:17:59.120 | and on other podcasts,

00:18:00.500 | that testosterone has this incredible effect

00:18:03.200 | of making effort feel good.

00:18:05.900 | But what I was really referring to

00:18:07.300 | is the fact that testosterone lowers stress and anxiety,

00:18:10.520 | in particular, in males of a given species.

00:18:14.280 | Now, this is important

00:18:15.340 | because we often think of testosterone

00:18:17.840 | as creating whatever, masculinization

00:18:20.900 | or it's virilization

00:18:23.460 | or all these terms are thrown around.

00:18:25.200 | But what's it really doing

00:18:26.260 | when it comes to mate choice and competition?

00:18:28.380 | What it's doing is it's reducing the threshold for anxiety.

00:18:31.760 | And in doing so,

00:18:32.880 | it selects individuals of a given species to push further,

00:18:36.860 | being willing to suffer more,

00:18:40.040 | although it also reduces pain,

00:18:41.340 | so maybe they also suffer less,

00:18:42.820 | in pursuit of reproduction in females.

00:18:45.780 | Now, it's well-known in humans

00:18:47.660 | that both males and females

00:18:49.620 | who have elevated levels of testosterone

00:18:51.940 | will engage in more novelty seeking.

00:18:54.080 | And I do want to point out

00:18:55.420 | that even individuals without testes have testosterone

00:18:59.460 | and peaks in testosterone have similar effects,

00:19:02.420 | regardless of whether or not someone has ovaries or testes.

00:19:06.180 | Testosterone increases generally lead to more foraging,

00:19:10.820 | more novelty seeking, increases in libido

00:19:13.780 | and increases in desire to mate.

00:19:16.240 | So it is the case that increases in testosterone

00:19:18.900 | promote competitive and foraging type behaviors

00:19:22.420 | in humans and in non-human mammals.

00:19:26.160 | But it's also true that competition itself

00:19:30.240 | can increase androgens such as testosterone.

00:19:33.280 | I want to repeat that.

00:19:34.180 | Competitive environments themselves

00:19:36.440 | can increase testosterone.

00:19:38.660 | Now, some people have come to the conclusion

00:19:41.560 | that if you win, your testosterone goes up,

00:19:43.900 | and if you lose, your testosterone goes down.

00:19:46.880 | And to some extent, that's true,

00:19:48.440 | but that's not a direct effect on the gonads.

00:19:50.540 | That's actually mediated by the neuromodulator dopamine.

00:19:53.320 | We talked about dopamine in the episode

00:19:55.020 | on motivation and drive.

00:19:56.660 | And dopamine and testosterone

00:19:58.260 | have a remarkable interplay in the body.

00:20:01.140 | Dopamine is actually released in the brain

00:20:03.260 | in ways that has the pituitary,

00:20:05.440 | this gland that sits over the roof of your mouth,

00:20:07.720 | release certain hormones that then go on

00:20:09.720 | to promote the release of more testosterone.

00:20:12.220 | And indeed, winning promotes more dopamine

00:20:15.980 | and later more testosterone.

00:20:18.700 | However, in the short term,

00:20:20.600 | just competing increases testosterone

00:20:23.180 | independent of whether or not you win or lose.

00:20:26.020 | So the short version of this

00:20:28.340 | is that competition increases testosterone.

00:20:32.180 | And this may be an ancient mechanism

00:20:34.120 | whereby the androgens, such as testosterone,

00:20:37.380 | are feeding back to encourage

00:20:38.860 | more competitive-type behaviors.

00:20:41.380 | Because every species,

00:20:42.780 | whether or not you're talking about reproduction

00:20:44.380 | or other resource allocation, is involved in competition.

00:20:47.620 | Not every individual of a species

00:20:49.540 | gets access to the same number of mates

00:20:51.620 | or the same quality of mates.

00:20:53.500 | And this is true in both directions,

00:20:54.980 | for males and females and everything in between.

00:20:57.180 | So I just want to emphasize once more,

00:20:59.260 | in case I went through it too quickly,

00:21:01.080 | that increases in testosterone in females

00:21:04.340 | are also going to lead to increase in reproductive behavior

00:21:08.560 | or seeking out reproductive behavior.

00:21:10.660 | They increase libido.

00:21:11.680 | In fact, there's a particular phase of the menstrual cycle

00:21:13.860 | where testosterone peaks just before ovulation

00:21:17.600 | that, on average, leads female humans to seek out sex

00:21:22.600 | more than they would otherwise during their cycle.

00:21:24.880 | And this is all by self-report,

00:21:26.460 | but this is also while measuring things like testosterone,

00:21:29.440 | estrogen ratios, and so forth.

00:21:31.160 | So it's really interesting that a single molecule,

00:21:33.440 | regardless of chromosomal or gonadal background,

00:21:36.160 | is increasing seeking of mates across individuals,

00:21:41.160 | increasing desire to compete or willingness to compete,

00:21:44.860 | and lowering the threshold for stress and anxiety.

00:21:48.220 | It's important to point out

00:21:49.440 | that while increases in testosterone

00:21:51.600 | promote seeking of mates and reproduction

00:21:55.620 | in both males and females,

00:21:57.740 | in females, it's actually increases in estrogen

00:22:01.100 | that promote receptivity to mating.

00:22:03.820 | So testosterone is driving the seeking of sex,

00:22:06.540 | and estrogen is promoting the actual act of sex from females,

00:22:11.540 | so-called receptivity, consensual receptivity.

00:22:14.860 | In males, it's interesting to point out

00:22:16.860 | that testosterone is promoting seeking of sex,

00:22:20.100 | but it's also estrogen in males that's important for libido.

00:22:24.780 | If estrogen levels are brought too low,

00:22:27.460 | then men will completely lose their libido.

00:22:29.580 | This is often not discussed or overlooked

00:22:31.960 | in the discussion about testosterone therapy

00:22:34.620 | and performance-enhancing drugs.

00:22:36.300 | People think that hyperandrogenized individuals,

00:22:38.980 | meaning people that have very high levels of androgen,

00:22:41.480 | will have very high levels of libido,

00:22:43.520 | and they will provided estrogen is available

00:22:46.900 | in sufficient ratios to match that testosterone.

00:22:49.840 | So it's not simply the case

00:22:51.180 | that high levels of testosterone

00:22:53.200 | produce a lot of sex and mating behavior,

00:22:56.180 | and low levels of estrogen are good across the board.

00:22:58.460 | You actually need both in both males and females.

00:23:01.300 | It's just that in females,

00:23:02.840 | the testosterone levels are always going to be lower

00:23:05.560 | than the estrogen levels,

00:23:06.580 | and in males, the estrogen levels

00:23:08.360 | are always going to be lower than testosterone levels.

00:23:10.740 | So testosterone promotes sex-seeking behavior,

00:23:14.340 | and the real question then is,

00:23:16.000 | does sex itself promote testosterone?

00:23:18.760 | And the answer is somewhat complicated,

00:23:21.540 | but the short version is yes.

00:23:24.720 | And as you recall, sex has multiple stages.

00:23:28.220 | So there's the physical act of sex,

00:23:30.180 | there's the seeking of sex,

00:23:31.560 | and then there's orgasm and ejaculation.

00:23:34.740 | Now, it's important to distinguish between these

00:23:37.760 | because whether or not sex itself increases testosterone

00:23:41.580 | depends on whether or not the male ejaculates.

00:23:44.820 | And this is very important to understand

00:23:46.820 | because on a previous episode,

00:23:48.540 | I mentioned how dopamine increases with sexual activity.

00:23:51.760 | Remember, dopamine and testosterone

00:23:53.520 | tend to increase linearly with one another,

00:23:56.860 | but then after ejaculation, there's a release of prolactin,

00:23:59.700 | and prolactin actually sets the refractory period in males

00:24:02.740 | during which he can't have sex again.

00:24:05.260 | And the duration of the refractory period

00:24:07.160 | will vary tremendously depending on how much

00:24:09.380 | and how long that prolactin release occurs.

00:24:12.260 | I also described in a previous episode

00:24:14.360 | how some people take vitamin B6,

00:24:16.980 | I'm not suggesting anyone do this,

00:24:18.100 | but take vitamin B6 in order to reduce prolactin levels

00:24:21.540 | and thereby reduce the duration of the refractory period.

00:24:24.640 | But getting at this question about testosterone

00:24:27.360 | and sexual behavior, it's important to distinguish

00:24:29.820 | between these different phases of reproduction

00:24:31.740 | or reproductive behaviors.

00:24:33.640 | So there are studies showing that sexual behavior itself

00:24:38.640 | can increase testosterone.

00:24:40.040 | There was a study published in 2011 from Escasa et al.,

00:24:43.360 | E-S-C-A-S-A, this is the stuff of textbooks,

00:24:46.420 | this is on PubMed, these are quality studies,

00:24:49.880 | showing that men who observe sex,

00:24:53.980 | so I guess this would be observing pornography,

00:24:56.920 | will have slight increases in testosterone

00:24:59.700 | during the observation.

00:25:01.080 | These people actually were willing to have blood draws taken

00:25:03.880 | while watching pornography.

00:25:05.740 | They had increases in testosterone

00:25:07.480 | that were very modest of about 10%.

00:25:10.640 | Whereas when people participated in sex,

00:25:13.560 | they actually did this study where people had blood draws

00:25:15.680 | and they had real sex with their partners,

00:25:18.320 | and they had 70% increases in testosterone.

00:25:22.240 | So there are increases in testosterone

00:25:24.400 | that are quite significant during the physical act of sex

00:25:29.040 | and far less so during observing sex.

00:25:32.480 | Now, the question that I often get,

00:25:34.260 | in fact, it's one of the questions I get most often

00:25:36.160 | in the comments on YouTube, I don't know why that is,

00:25:38.680 | is whether or not ejaculation adjusts testosterone levels.

00:25:43.680 | And it turns out there are two studies that I could find

00:25:47.120 | that were quality studies on PubMed that addressed this,

00:25:50.000 | that sex and ejaculation itself

00:25:52.200 | does not reduce testosterone levels,

00:25:54.800 | although it will increase prolactin levels

00:25:57.340 | for the reasons I described a moment ago.

00:25:59.400 | However, abstinence or sex without ejaculation

00:26:04.400 | for a week or more will increase testosterone levels

00:26:09.000 | up to 400%.

00:26:11.440 | So the answer is actually complicated.

00:26:13.920 | It's not straightforward.

00:26:15.440 | What it means is that sex itself increases testosterone.

00:26:18.600 | However, abstinence also increases testosterone even further.

00:26:22.560 | So it's a nuanced answer.

00:26:24.660 | And I hope this is satisfactory, no pun intended,

00:26:27.560 | to those of you that have been asking me

00:26:29.560 | what is the relationship between sex and ejaculation

00:26:33.020 | and testosterone and dopamine?

00:26:34.760 | It is nuanced.

00:26:36.200 | And you have to understand that nuance

00:26:38.360 | if you want to understand how certain behaviors

00:26:40.960 | impact hormones and how hormones impact those behaviors.

00:26:44.160 | As I mentioned before, in females,

00:26:46.080 | testosterone also primes the motivation to seek out sex.

00:26:51.020 | And sex itself also increases testosterone,

00:26:55.880 | but it also increases prolactin.

00:26:58.040 | So in both men and women, sex increases prolactin post sex.

00:27:03.040 | It's just the way that the system works.

00:27:06.320 | It's that testosterone and dopamine increase

00:27:08.560 | in the seeking out and the behavior of sex.

00:27:12.160 | And then after sex, prolactin levels go up.

00:27:15.920 | There's kind of a quiescence.

00:27:17.080 | The whole nervous system is promoted towards calm.

00:27:19.220 | And this may actually have something to do with pair bonding

00:27:21.440 | and the encouragement of individuals

00:27:23.780 | to spend more time together to exchange different smells

00:27:26.260 | and hormones and maybe even pheromones.

00:27:27.880 | And we're going to talk about pheromones in a moment.

00:27:29.880 | A few years ago, there was a lot of excitement

00:27:31.900 | about the hormone DHEA,

00:27:33.840 | which is mainly made by the adrenals.

00:27:35.960 | DHEA has been promoted as kind of a catchall

00:27:40.240 | for increasing testosterone and estrogen

00:27:42.600 | in males and females.

00:27:43.600 | And indeed DHEA will increase both testosterone and estrogen.

00:27:48.140 | This is something to be mindful of

00:27:49.720 | if you're thinking about taking DHEA

00:27:51.400 | or you're taking DHEA already.

00:27:54.600 | DHEA will increase both testosterone and estrogen.

00:27:57.800 | And the extent to which it increases one or the other

00:28:00.800 | will depend on whether or not you're starting off

00:28:02.720 | with more estrogen than testosterone,

00:28:04.680 | or whether or not you're starting off

00:28:05.520 | with more testosterone than estrogen,

00:28:07.080 | and whether or not you have a lot of aromatase.

00:28:09.360 | So for individuals that have a lot of aromatase

00:28:11.400 | being made by the testes or by body fat,

00:28:13.760 | if you take DHEA, there's a good chance

00:28:15.560 | that a fair portion of that is going to be shuttled

00:28:17.560 | towards estrogen production

00:28:19.000 | and not towards testosterone production.

00:28:21.400 | Whereas in individuals that have low levels of testosterone

00:28:24.140 | to begin with, high levels of estrogen,

00:28:25.920 | there's a good chance that the DHEA

00:28:27.240 | is going to promote mainly estrogen production.

00:28:29.360 | At least that's what I could find

00:28:30.880 | from the research studies that I examined.

00:28:33.080 | So the way to think about DHEA,

00:28:34.560 | it's a kind of global promoter of the sex steroid hormones,

00:28:39.520 | and its specific effects are going to depend

00:28:41.640 | a little bit on where you started

00:28:43.040 | and whether or not you have ovaries or testes.

00:28:45.200 | So just as there are behaviors

00:28:46.460 | that can increase testosterone,

00:28:48.580 | there are behaviors that can decrease testosterone.

00:28:51.840 | And one of the most well-characterized ones in humans

00:28:55.600 | is becoming a parent.

00:28:58.320 | So expecting fathers have an almost 50% decrease

00:29:03.580 | in testosterone levels, both free and bound testosterone.

00:29:08.020 | As well, their cortisol levels, a stress hormone,

00:29:12.180 | drop by almost threefold, which is incredible.

00:29:15.640 | And their estradiol levels double,

00:29:18.340 | so their estrogen levels double.

00:29:20.200 | So expecting fathers, many people have known,

00:29:23.160 | put on additional body weight.

00:29:24.880 | Everyone always thought that it's because they're eating

00:29:26.940 | in parallel with their pregnant wife,

00:29:29.360 | but it turns out that these effects of reduced testosterone,

00:29:32.740 | increased estradiol, and reduced cortisol

00:29:35.080 | can all be explained by an increase in prolactin.

00:29:38.880 | So not just in humans, but in other species as well.

00:29:43.000 | When the male and female of that species

00:29:45.760 | are expecting young, they lay down more body fat.

00:29:49.380 | The assumption is that this is to prepare

00:29:51.120 | for long nights of no sleep,

00:29:53.200 | which occurs in many species, not just in humans.

00:29:56.460 | So it's really interesting that this hormone prolactin

00:29:59.840 | can start suppressing whole categories of hormones,

00:30:03.640 | sex steroid hormones,

00:30:04.780 | and can start increasing whole categories of other ones.

00:30:08.040 | So we hear about the dad bod.

00:30:09.580 | There are a lot of explanations for the dad bod

00:30:12.180 | that extend well beyond this podcast episode,

00:30:14.580 | but it is a well-known phenomenon

00:30:17.180 | that testosterone is going to drop,

00:30:18.820 | prolactin is going to increase,

00:30:20.380 | estradiol is going to increase in males and females

00:30:23.900 | that are expecting children.

00:30:25.940 | Now, how long that lasts is very interesting.

00:30:28.460 | It actually has to do with how much contact

00:30:31.820 | and how much contact with the smells of the baby,

00:30:35.100 | of the offspring the father happens to have.

00:30:37.380 | So how available or unavailable he is

00:30:39.860 | will actually impact his level of hormones.

00:30:41.900 | Now, I am definitely not promoting the idea

00:30:43.680 | that fathers or mothers take time away from their offspring

00:30:47.020 | in order to keep their testosterone levels high

00:30:48.900 | or to restore them.

00:30:50.180 | That's not what I'm saying at all.

00:30:51.660 | It's just interesting to point out

00:30:53.020 | that these evolutionary mechanisms push us toward

00:30:55.700 | or bias us toward particular categories of behaviors

00:30:59.360 | by influencing our hormones,

00:31:00.940 | which then feed back and promote more

00:31:02.780 | of that particular behavior.

00:31:04.160 | Because as I mentioned before,

00:31:05.900 | peaks in testosterone in males and females

00:31:08.680 | cause individuals to seek sex, not promote parenting.

00:31:12.300 | Whereas reductions in testosterone, increases in prolactin,

00:31:16.140 | and decreases in cortisol move individuals of both sexes

00:31:20.280 | toward parenting behavior

00:31:21.780 | and less toward reproductive behavior.

00:31:23.780 | The other behavior that markedly reduces testosterone

00:31:27.440 | in both males and females,

00:31:29.100 | and markedly reduces the desire for seeking sex

00:31:32.260 | and sex itself is illness.

00:31:35.240 | And many of you might say, well, duh,

00:31:37.500 | when people don't feel sick,

00:31:38.600 | they don't feel like seeking out mates

00:31:40.140 | and they don't feel like having sex.

00:31:41.620 | But have you ever wondered why that actually is?

00:31:44.140 | Well, it turns out that it can be explained by the release

00:31:47.260 | of what are called inflammatory cytokines.

00:31:49.760 | So cytokines are related to the immune system.

00:31:52.300 | They travel in the lymph and in the blood,

00:31:54.260 | and they attack invader cells like bacteria and viruses.

00:31:57.940 | And under conditions of illness,

00:31:59.940 | we make a lot of different cytokines.

00:32:01.700 | Some of them are anti-inflammatory,

00:32:03.660 | but some of them are pro-inflammatory.

00:32:05.780 | And the best known example of a pro-inflammatory cytokine

00:32:08.900 | is IL-6.

00:32:10.940 | And it's known that IL-6, when injected into individuals,

00:32:15.220 | will decrease the desire for sex,

00:32:17.700 | and eventually will reduce levels of testosterone

00:32:20.380 | and estrogen, independent of feeling lousy.

00:32:23.620 | So the reason why people don't want sex when they're sick

00:32:27.740 | is because levels of IL-6 are increased.

00:32:30.040 | Now, this is important because as we start to think about

00:32:32.620 | the different ways to modulate the sex steroid hormones,

00:32:35.500 | so-called optimize the hormones,

00:32:37.240 | keeping levels of IL-6 low is going to be important

00:32:42.020 | for them to exert their effects.

00:32:44.100 | Now, IL-6 doesn't just travel to the gonads

00:32:46.460 | and shut down the gonads.

00:32:47.460 | It actually has ways to interact

00:32:50.000 | with some of the receptors that the steroid hormones,

00:32:52.360 | estrogen and testosterone bind to,

00:32:54.460 | and impact those receptors

00:32:55.860 | so that the sex steroid hormones can't have their effect.

00:32:58.600 | In short, and put simply,

00:33:00.660 | inflammatory cytokines like IL-6

00:33:02.900 | are bad for sex steroid hormones.

00:33:04.740 | And so we're going to talk about how to modulate IL-6

00:33:07.200 | in the direction that you would want,

00:33:08.980 | and how to increase another cytokine called IL-10,

00:33:13.300 | which is anti-inflammatory,

00:33:15.060 | in ways that can help promote

00:33:16.620 | or at least support the sex steroid hormones.

00:33:19.180 | So as we move forward,

00:33:20.360 | we're going to now start to consider

00:33:22.180 | what sorts of behavioral practices,

00:33:24.420 | as well as other things,

00:33:26.040 | can modulate the sex steroid hormones

00:33:28.140 | in the directions that you want them to go.

00:33:30.340 | But before we do that,

00:33:32.740 | and in order to set the stage for that,

00:33:35.440 | you should be asking yourself,

00:33:37.180 | how is it or why is it at a mechanistic level

00:33:41.080 | that behaviors can modulate hormones at all?

00:33:44.040 | If you think about it,

00:33:44.980 | it's kind of strange that just the mere act

00:33:47.240 | of being a parent or parenting

00:33:49.480 | can change testosterone levels so dramatically

00:33:52.000 | or estradiol levels so dramatically.

00:33:54.560 | What is it?

00:33:55.400 | Is it the sweat of the baby?

00:33:56.840 | Is it their saliva?

00:33:58.360 | Is it the sight of the baby?

00:33:59.720 | Is it holding the baby?

00:34:01.000 | Or is it all those things?

00:34:02.700 | It turns out that many of those effects

00:34:05.060 | are because of smell,

00:34:06.780 | or in some cases, even possibly pheromones.

00:34:11.020 | Now I talked about hormones.

00:34:12.240 | Hormones, again, are a chemical,

00:34:13.720 | travels in the body,

00:34:14.560 | impacts tissues and cells elsewhere in the body.

00:34:17.040 | A pheromone is a chemical that's released

00:34:19.180 | by one member of a species

00:34:20.720 | that goes and impacts members elsewhere,

00:34:24.080 | but of the same species or even of other species.

00:34:26.920 | Now pheromone effects are absolutely well-established

00:34:30.780 | in lots of animal species,

00:34:32.340 | but they are very controversial in humans.

00:34:34.760 | Today, I'm going to talk about

00:34:36.140 | some of the well-established ones in animals.

00:34:38.400 | I've mentioned one or two of these before

00:34:40.400 | on previous podcasts,

00:34:41.760 | but I haven't mentioned several of them.

00:34:44.420 | And I'm going to talk about the evidence

00:34:47.420 | for pheromones in humans that are well-established.

00:34:51.740 | So the main ones in animals that are discussed

00:34:54.720 | are called the Lie-Bute effect,

00:34:56.060 | the Witten effect, the Bruce effect,

00:34:57.500 | and the Vandenberg effect,

00:34:58.460 | named after the people that discovered them.

00:35:00.660 | The Lie-Bute effect is when you house females

00:35:04.120 | of a given species together with no males,

00:35:07.360 | they start displaying longer,

00:35:08.900 | what are called estrous cycles.

00:35:10.320 | In many species, they don't have menstrual cycles,

00:35:12.700 | which are 28 days.

00:35:13.820 | They have estrous cycles,

00:35:15.140 | which tend to be four days or some variant thereof.

00:35:18.100 | It's an interesting phenomenon

00:35:21.460 | because what it means is that the presence of the male itself

00:35:24.480 | is changing the ovulation cycle.

00:35:28.120 | Now, many people out there,

00:35:30.000 | imagine mostly the people that are ovulating out there,

00:35:33.200 | will say, "Of course, I notice I ovulate differently

00:35:35.480 | or my cycle changes when I'm in the presence of my partner

00:35:38.400 | or I'm not."

00:35:39.380 | But the pheromone effect

00:35:40.560 | that mirrors this Lie-Bute effect in humans

00:35:43.800 | has still not really been identified.

00:35:45.400 | Nobody knows what the exact chemical is,

00:35:47.320 | but nonetheless, this is a strong effect in some animals.

00:35:50.240 | The other one is the Bruce effect,

00:35:52.320 | and this is a very dramatic effect

00:35:53.800 | whereby a pregnant animal will abort or reabsorb her fetus

00:35:58.800 | if the dad of those animals,

00:36:01.320 | the father that sired the litter,

00:36:03.800 | 'cause these are animals, they're litters,

00:36:06.360 | is removed and a novel male is placed in her vicinity

00:36:11.360 | for about 48 hours.

00:36:12.800 | And what's interesting is the way that this happens

00:36:15.480 | is a pheromone that comes from male urine

00:36:18.800 | activates the gonadotropin-releasing hormone system

00:36:23.820 | and causes a reintroduction of the estrous cycle

00:36:28.480 | and a spontaneous abortion of the fetus.

00:36:30.920 | Now, a lot of people have taken the Bruce effect

00:36:33.220 | kind of to its extreme and asked

00:36:34.840 | whether or not in humans, miscarriages are caused

00:36:37.240 | by detecting the pheromones or odors of novel males,

00:36:40.400 | meaning the non-dad male, and that's still an open question.

00:36:43.600 | Nobody knows if that's true or not,

00:36:45.320 | so I want to emphasize that.

00:36:47.480 | The other one is the Vandenberg effect,

00:36:49.100 | and this is one I alluded to

00:36:50.120 | in a previous episode of the podcast,

00:36:51.740 | which is that puberty in females can be accelerated

00:36:55.420 | by placing a novel sexually competent male

00:36:58.260 | in with a young female who has not undergone puberty.

00:37:01.420 | There's also a version of this, which I haven't described,

00:37:04.640 | which is delay of puberty,

00:37:06.480 | where you take juvenile female animals

00:37:09.240 | that have not undergone puberty,

00:37:11.080 | and you put them with more mature females

00:37:13.800 | of the same species,

00:37:15.780 | and that introduction of more females will cause a delay,

00:37:20.640 | a significant delay in the onset of puberty.

00:37:23.240 | So these are all pheromone effects,

00:37:24.880 | and we know they're pheromone effects

00:37:26.320 | because they're not conscious.

00:37:28.460 | They also don't require actual contact

00:37:31.060 | with the other members of a given species.

00:37:33.680 | These are all effects that can be mediated

00:37:35.420 | by the urine from a given species

00:37:38.200 | or by the sweat of a given species.

00:37:40.080 | And speaking of sweat, the one pheromone effect

00:37:43.320 | that I'm very aware of from the published literature

00:37:47.580 | is a paper that was published in 1998

00:37:50.920 | by Stern and McClintock,

00:37:52.720 | which was getting at this question

00:37:53.880 | of synchronization of menstrual cycles.

00:37:55.640 | Now, the whole idea of synchronization of menstrual cycles

00:37:59.340 | is pretty controversial.

00:38:01.320 | For a long time, people said,

00:38:02.480 | "Oh, this is absolutely a well-characterized phenomenon."

00:38:06.000 | People living in dormitories,

00:38:07.440 | their menstrual cycles would synchronize.

00:38:09.980 | People living in environments together,

00:38:11.840 | their menstrual cycles would synchronize.

00:38:14.420 | And then some studies came out

00:38:16.040 | that kind of undercut those data

00:38:18.520 | and said, "No, this actually doesn't happen,"

00:38:20.320 | and it was kind of controversial.

00:38:21.800 | But there is a very clear effect

00:38:24.400 | that was described by Stern and McClintock.

00:38:26.720 | What they did actually was they took females,

00:38:30.440 | they charted their cycles,

00:38:32.520 | and then they had other females wear pads in their armpits,

00:38:37.520 | and they collected sweat from those females.

00:38:40.800 | And then they took the sweat from those pads

00:38:43.600 | in those females' armpits,

00:38:45.200 | and they introduced them to women

00:38:46.520 | who had never had contact with the people who had sweated.

00:38:50.600 | They only had contact with their sweat.

00:38:52.200 | In fact, they swabbed it underneath their nose.

00:38:54.080 | But if that sounds gross, they dilute it in alcohol,

00:38:57.600 | so much so that they can't actually detect

00:38:59.600 | the odor of the sweat.

00:39:01.120 | That's actually very important because it's not the smell,

00:39:03.760 | it's the pheromone chemical itself.

00:39:06.560 | And it turns out the pheromone chemical itself

00:39:08.620 | can modulate the menstrual cycle,

00:39:12.400 | although it doesn't necessarily synchronize it

00:39:14.800 | with the sweater.

00:39:16.240 | What it does is it changes the duration

00:39:20.640 | and the pattern of ovulation

00:39:22.340 | relative to so-called follicular phase.

00:39:24.740 | Long and short of this is that the sweat and pheromones

00:39:29.580 | of females can modulate the menstrual cycle patterns

00:39:34.060 | of other adult females.

00:39:35.800 | It's just a question of whether or not they synchronize.

00:39:38.140 | And if you're kind of rolling your eyes now and saying,

00:39:39.980 | well, of course they do, and this is really detailed,

00:39:42.260 | this is how the science is done.

00:39:44.100 | And the reason why people are so skeptical

00:39:47.680 | about the presence of pheromone effects in humans

00:39:50.620 | is that there's no well-identified pheromone organ.

00:39:54.780 | We have an area of our nose that's responsible for smelling,

00:39:57.200 | that's well-established, it's been observed in MRIs

00:40:00.700 | many, many times in cadavers, many, many times

00:40:02.880 | in pretty much all individuals.

00:40:04.700 | But the vomeronasal organ,

00:40:06.960 | which is the pheromone detecting organ,

00:40:08.700 | hasn't really been found in humans.

00:40:10.600 | There's something called Jacobson's organ,

00:40:12.220 | which is thought to be the organ in the nose.

00:40:14.620 | It's actually on the top of the roof of the mouth

00:40:17.020 | and in the kind of back of the nose.

00:40:18.620 | This is for a few wine tasters, I never can pronounce this.

00:40:21.620 | What are they called?

00:40:22.460 | Sommelier, whatever, it's the people that are excellent

00:40:25.580 | at drinking and detecting the essences of wine

00:40:29.460 | that you have to go through all these tests

00:40:30.780 | in order to get certified as one of them.

00:40:32.800 | Somebody tell me.

00:40:33.700 | They are using probably a similar mechanism

00:40:38.140 | of mixing taste and smell.

00:40:39.820 | And Jacobson's organ, if it exists,

00:40:42.900 | the vomeronasal equivalent in humans

00:40:45.940 | is thought to be a combination of smell and taste.

00:40:49.280 | Now, it gets even weirder and cooler

00:40:52.720 | when you think about a given study that was done in humans

00:40:55.400 | where if you take hundreds of t-shirts from boyfriends,

00:41:00.400 | keep them separate, you take those t-shirts,

00:41:03.160 | you wash them many times separately,

00:41:05.940 | and then you offer them to the girlfriends,

00:41:08.660 | the longtime partners of those guys.

00:41:11.980 | And what you'll find is that the girlfriend

00:41:15.820 | can pick out her boyfriend's t-shirt

00:41:18.580 | among hundreds of other t-shirts,

00:41:21.220 | not because it smells different,

00:41:22.720 | but because something about it seems different.

00:41:25.340 | It might smell different to her

00:41:27.460 | in some way that's kind of imperceptible even to her.

00:41:30.500 | And the level of accuracy in detecting that t-shirt,

00:41:34.420 | her partner's t-shirt,

00:41:35.520 | is way above statistical significant thresholds,

00:41:39.120 | so much so that you almost have to say

00:41:41.020 | there's something about these effects

00:41:42.740 | that are real pheromone effects.

00:41:44.740 | Although people still argue

00:41:45.980 | that there are no pheromone effects in humans,

00:41:47.560 | that it's all through olfaction,

00:41:49.100 | I think these are interesting and important to understand

00:41:51.060 | because it means that a lot of things

00:41:52.260 | coming through our nose,

00:41:53.500 | whether or not it's pheromones or smells,

00:41:55.780 | are impacting hormones and our ability to attach memories

00:41:59.500 | and kind of recognition of mates and other people,

00:42:02.260 | including our children, not just our mates.

00:42:04.380 | And of course, perfume manufacturers

00:42:06.420 | have really picked up on the idea of pheromones

00:42:08.700 | and have entire laboratories set up

00:42:10.900 | to build chemical compounds into perfumes

00:42:13.620 | that are designed to attract other mates.

00:42:15.360 | This is a well-established and well-documented phenomenon.

00:42:18.820 | And the last point I'll make about pheromones

00:42:21.180 | is that this combination of taste and smell

00:42:24.220 | is such a real thing in the animal world

00:42:27.260 | that there's something called the flemming response.

00:42:30.040 | During the mating season for different animals,

00:42:33.460 | you can actually even see this in horses,

00:42:35.060 | but for animals that are seasonal maters,

00:42:36.980 | they'll do something called the flemming response

00:42:38.740 | where they actually open their lips and their mouth

00:42:41.660 | and they expose their gums

00:42:43.820 | so that they can capture pheromones

00:42:46.700 | that are floating in the wind and the environment.

00:42:48.420 | They actually are looking for mates using their mouth

00:42:51.140 | and kind of sniffing around.

00:42:52.220 | If you own a dog and you watch the way

00:42:53.620 | that the dog will sniff around,

00:42:55.120 | selecting where they want to urinate, males and females,

00:42:58.020 | there's often, they're bringing molecules into their nose.

00:43:01.980 | I know it sounds kind of gross sniffing urine,

00:43:03.660 | but there are a lot of pheromones in urine of animals.

00:43:06.120 | A lot of pheromones are traveling in the wind.

00:43:08.700 | Again, whether or not this is happening in humans,

00:43:10.660 | I don't know, but then you think about the perfume thing

00:43:12.940 | and here people are putting these scents on themselves

00:43:15.700 | that contain putative pheromones, human pheromones,

00:43:19.300 | and walking around hoping that their scents

00:43:21.020 | are going to evoke mate-seeking behavior

00:43:24.140 | from other individuals of the same human species.

00:43:26.900 | So we are among the animals in this behavior

00:43:30.060 | independent of whether or not

00:43:31.100 | you believe pheromone effects exist.

00:43:32.860 | So let's get back to behaviors

00:43:34.460 | that can help optimize hormone levels.

00:43:37.820 | One of the main behaviors that's been shown to be associated

00:43:41.860 | with poor levels of estrogen

00:43:45.660 | relative to age-match controls for people with ovaries

00:43:48.980 | or lower levels of testosterone

00:43:51.700 | compared to age-match controls for people with testes

00:43:55.060 | is apnea.

00:43:58.040 | Apnea has everything to do with underbreathing

00:44:02.980 | and the buildup of too much carbon dioxide in the body.

00:44:06.280 | There are other effects of apnea as well.

00:44:08.900 | But if there's a consistent literature in this whole story

00:44:13.540 | about aging and reductions in hormones and general health

00:44:17.340 | and reductions in hormones, it's apnea.

00:44:20.520 | I went deep into the literature on advanced menopause

00:44:23.820 | or when menopausal symptoms are exacerbated.

00:44:27.420 | And I went into the literature on andropause

00:44:29.860 | or early onset andropause.

00:44:31.740 | So levels of testosterone that are far lower

00:44:34.260 | than they should be for a given age.

00:44:36.820 | And in every case, you could find multiple papers

00:44:41.040 | that showed that apnea or poor efficiency of breathing

00:44:45.780 | and buildup of too much carbon dioxide in the body

00:44:48.880 | was a problem.

00:44:49.720 | Mostly sleep apnea, although apnea in general

00:44:53.640 | was shown to be an issue negatively impacting hormones.

00:44:56.780 | Now, the directionality of this effect isn't entirely clear.

00:45:00.580 | It could be that reductions in estrogen cause apnea.

00:45:04.380 | And actually there's some reason to believe

00:45:06.180 | that might be the case.

00:45:07.020 | I found at least one paper showing

00:45:09.440 | that there are estrogen receptors on some of the neurons

00:45:13.180 | that actually innervate the lungs

00:45:15.740 | and allow for the perception of how full

00:45:18.140 | or empty the lungs are.

00:45:19.420 | In other words, reductions in estrogen may adjust breathing

00:45:23.340 | by changing our sensitivity to our own lungs.

00:45:26.840 | Now, that was true for males and females.

00:45:29.420 | Remember, estrogen in both males and females.

00:45:31.900 | But as well, I found papers in which testosterone reductions

00:45:36.540 | were associated with apnea and testosterone receptors

00:45:40.140 | are also found on a lot of cells in the so-called viscera,

00:45:44.860 | including the lungs.

00:45:46.300 | So again, the directionality of the effect isn't clear.

00:45:49.180 | But what's really interesting is that

00:45:51.140 | there are very clear ways in which patterns of breathing,

00:45:54.300 | especially patterns of breathing in sleep

00:45:56.580 | can modulate hormones in ways that are immediately

00:45:59.620 | actionable and can serve to optimize

00:46:01.920 | both estrogen and testosterone,

00:46:03.780 | regardless of whether or not you have ovaries or testes.

00:46:06.580 | So what is apnea?

00:46:08.060 | Apnea is under-breathing

00:46:09.780 | or mainly cessation of breathing during sleep.

00:46:13.300 | So people are holding their breath

00:46:14.540 | and then they'll suddenly wake up.

00:46:16.500 | Actually, I've talked about the physiological sigh

00:46:18.700 | on previous episodes of this podcast

00:46:20.880 | of this pattern of double inhales followed by exhales

00:46:24.180 | that one can do consciously to reduce stress

00:46:26.420 | and anxiety and offload carbon dioxide.

00:46:28.780 | That pattern of breathing is actually

00:46:30.340 | what kicks in spontaneously

00:46:32.340 | anytime we have an apnea episode in sleep.

00:46:35.160 | Although in many people who have apnea,

00:46:36.860 | they don't engage the physiological sigh.

00:46:39.600 | People who are dramatically overweight

00:46:42.820 | also suffer a lot from apnea during sleep.

00:46:45.500 | There's actually a lot of buildup of carbon dioxide

00:46:47.640 | in the body, and that can lead to excessive sleepiness

00:46:50.440 | during the day, inability to access

00:46:52.500 | the deeper phases of sleep.

00:46:54.220 | And it's well-established that going into deep sleep

00:46:59.060 | and getting the proper patterns of slow wave sleep

00:47:01.140 | and REM sleep are important for hormone optimization.

00:47:04.160 | I talked about how to modulate sleep and optimize sleep

00:47:07.720 | in the first month of the Huberman Lab Podcast.

00:47:09.820 | So please check out those episodes

00:47:11.020 | if you have sleep issues or you want to work on your sleep.

00:47:13.900 | Also check out Matt Walker's terrific book, "While We Sleep,"

00:47:17.040 | and that will help you find various protocols

00:47:20.140 | to help you optimize your sleep.

00:47:22.220 | But the issue of breathing itself

00:47:25.300 | can be adjusted in the daytime waking hours

00:47:28.340 | in ways that can powerfully impact both sleep,

00:47:31.140 | reduce incidents of sleep apnea,

00:47:33.340 | and apparently from some emerging literature

00:47:36.620 | can also help to optimize various hormones

00:47:39.500 | even just by breathing in particular ways while awake.

00:47:42.500 | So here's how this works.

00:47:43.780 | There's now a lot of literature showing

00:47:46.660 | that breathing through the nose, not through the mouth,

00:47:48.940 | is powerful for improving lots of things.

00:47:51.980 | First of all, it improves cosmetic features

00:47:54.540 | of the jaw and face.

00:47:55.500 | This was first well-established by my colleagues at Stanford

00:47:59.080 | in a book called "Jaws," the story of a hidden epidemic.

00:48:02.460 | This is by Sandra Kahn and Paul Ehrlich,

00:48:04.700 | who are both faculty at Stanford,

00:48:06.680 | has a foreword by Robert Sapolsky,

00:48:08.620 | the great Robert Sapolsky,

00:48:10.180 | and it also has a heavy endorsement up front

00:48:13.700 | by Jared Diamond, the author of "Guns, Germs, and Steel,"

00:48:16.520 | the Pulitzer winner.

00:48:17.500 | So a lot of heavy hitters on this book, "Jaws."

00:48:19.460 | It's not a book that a lot of people know about unfortunately

00:48:22.220 | but it really describes the benefits of nasal breathing

00:48:26.020 | and the terrible things that happen

00:48:28.900 | when people, in particular children but adults also,

00:48:31.460 | are heavy mouth breathers.

00:48:33.260 | So mouth breathers have changes in the cosmetics

00:48:35.740 | of their face and jaw that are really bad

00:48:39.000 | in terms of attractiveness,

00:48:40.560 | and this was done in twin studies.

00:48:41.900 | You can look in the book and see some of this.

00:48:43.240 | It's really dramatic how being a mouth breather

00:48:46.180 | tends to make the chin drop back behind the upper mandible.

00:48:49.540 | There's a lengthening in the face, a drooping of the eyes.

00:48:51.840 | It can be quite dramatic or modest

00:48:53.460 | depending on how much mouth breathing.

00:48:55.380 | Now, sometimes we have to breathe with our mouths,

00:48:57.200 | but there's also a lot of data and studies

00:48:59.420 | described in this book, "Jaws,"

00:49:01.300 | that describe how nose breathing in wakefulness

00:49:05.020 | and in sleep promotes all sorts of positive things

00:49:08.780 | related to not just cosmetics

00:49:11.500 | but also the improvement of gas exchange of carbon dioxide

00:49:15.260 | and oxygen in the body.

00:49:17.140 | And as well, it can modify levels

00:49:20.260 | of different neurotransmitters and neuromodulators

00:49:22.580 | in ways that positively can impact hormones.

00:49:25.660 | So believe it or not, being a nasal breather

00:49:28.780 | and avoiding being a mouth breather

00:49:30.520 | can actually positively impact hormones,

00:49:33.420 | and in particular, the hormones testosterone and estrogen,

00:49:36.460 | although the way that it does that

00:49:38.700 | is by making you a better sleeper,

00:49:41.260 | which allows you to produce more testosterone

00:49:43.940 | and the appropriate amounts of testosterone and estrogen.

00:49:47.300 | But it does that in part through indirect mechanisms

00:49:52.200 | because deep sleep supports the gonads,

00:49:54.180 | the ovaries and the testicles,

00:49:55.860 | and the turnover of cells and the production of cells.

00:49:58.600 | Remember, in the ovary, particular cells

00:50:01.340 | and the egg follicles themselves make estrogen,

00:50:03.780 | and in the testicle that the sertoli cells

00:50:08.780 | and the lytic cells are important

00:50:10.800 | for the formation of sperm and for testosterone respectively.

00:50:14.360 | So what does this all mean?

00:50:16.620 | This means we have to be breathing properly.

00:50:19.060 | It almost sounds kind of like kind of new agey,

00:50:22.300 | like, oh, you have to breathe properly,

00:50:23.560 | get your hormones right,

00:50:24.480 | but no, you have to breathe properly

00:50:26.520 | to get your breathing and sleep right

00:50:28.100 | so that your sleep can actually be deep enough

00:50:30.120 | and you're not entering apnea states,

00:50:32.320 | and then that will support gonad function.

00:50:35.240 | And I wouldn't be putting this out

00:50:36.800 | as one of the main behavioral tools upfront

00:50:39.440 | if it weren't for the fact that the effects of apnea

00:50:42.120 | on these hormones are dramatic and terrible,

00:50:44.800 | and the positive effects of getting breathing right

00:50:47.160 | on these hormones, testosterone and estrogen,

00:50:49.080 | are dramatic and wonderful.

00:50:50.880 | So let's talk about a few of those studies briefly

00:50:52.860 | so I can underscore the value of proper breathing

00:50:56.120 | in order to optimize hormones.

00:50:57.980 | So I was able to find at least four quality studies

00:51:01.180 | showing that when apnea is reduced in sleep or eliminated,

00:51:06.000 | there are significant increases in testosterone in males

00:51:09.860 | and in proper estrogen to testosterone ratios in females.

00:51:13.900 | And the way that it works is very interesting.

00:51:17.000 | Apparently, it works by reductions in cortisol.

00:51:21.240 | Now, cortisol is a stress hormone

00:51:22.900 | that is released early in the day as we wake up

00:51:25.000 | and serves healthy roles in protecting us against infection,

00:51:27.920 | reducing inflammation, et cetera,

00:51:29.880 | but you don't want cortisol to be too high

00:51:31.800 | and you certainly don't want to elevate it too long

00:51:34.080 | throughout the day and night.

00:51:36.100 | And so we all know, because now we've been told a lot

00:51:39.480 | in the last decade or so, that getting proper sleep

00:51:42.540 | is important for all these aspects of health.

00:51:44.240 | Getting proper sleep can really offset all the reductions

00:51:47.480 | in testosterone and estrogen and reductions in fertility

00:51:50.320 | that occur if we don't get enough sleep,

00:51:52.020 | but seldom is it discussed how sleep actually adjusts

00:51:55.840 | things like testosterone and estrogen,

00:51:57.720 | and it does it by modifying cortisol.

00:52:01.000 | So the molecule cholesterol can be converted

00:52:04.920 | into testosterone or estrogen,

00:52:06.920 | but there's a competition whereby the cholesterol

00:52:10.600 | will turn into cortisol and not testosterone,

00:52:13.920 | or it'll turn into cortisol and not estrogen

00:52:17.680 | if stress levels are too high.

00:52:19.660 | So the simple version of this is getting your breathing

00:52:22.600 | right during the waking hours, meaning primarily,

00:52:26.040 | unless you're working out really hard

00:52:27.840 | or there's some other reason why you're maybe eating

00:52:30.100 | or speaking that you need to be breathing through your mouth,

00:52:32.080 | you should be a nose breather.

00:52:33.600 | There's really good evidence for that now.

00:52:36.080 | And in sleep, you also want to be a nose breather

00:52:38.960 | because that's going to increase the amount of oxygen

00:52:41.620 | that you're bringing into your system

00:52:42.620 | and the amount of carbon dioxide that you're offloading.

00:52:45.460 | There are other positive effects of it as well,

00:52:47.280 | but you're basically reducing apnea.

00:52:49.420 | Breath holding in sleep leads to buildup of carbon dioxide

00:52:52.080 | and leads to increases in cortisol,

00:52:54.020 | which then decrease testosterone and decrease estrogen

00:52:58.000 | in negative ways across all sexes, okay?

00:53:01.340 | So the simple version of this is get your breathing right.

00:53:04.000 | So how do you do that?

00:53:04.840 | How do you get your breathing right?

00:53:05.820 | Well, for some people that have severe sleep apnea,

00:53:08.800 | they're going to need the CPAP machine.

00:53:10.560 | This is a machine that you actually put on your face

00:53:12.260 | and it helps you breathe properly in sleep.

00:53:14.580 | Many people, however, are starting to do this thing

00:53:16.740 | of taping their mouth shut.

00:53:17.820 | Now, this sounds a little bit extreme

00:53:20.000 | and you certainly don't want to do this

00:53:21.560 | in any way that's dangerous.

00:53:22.620 | James Nestor talked about this in his book,

00:53:25.340 | "Breath, The New Science of a Lost Art,"

00:53:27.480 | that simply taping shut the mouth with some tape

00:53:30.380 | that will allow you to open your mouth if you really need to

00:53:33.960 | during sleep can allow people to shift over

00:53:36.060 | from being mouth breathers and snorers to nose breathers.

00:53:40.540 | In the daytime, the best way to get good at nasal breathing

00:53:44.420 | is to dilate the nasal passages

00:53:46.140 | 'cause a lot of people have a hard time

00:53:47.500 | breathing through their nose.

00:53:49.220 | And one way to do this

00:53:50.560 | is to just breathe through your nose more.

00:53:52.340 | And one way to do that is that when you exercise,

00:53:54.660 | in particular cardiovascular exercise,

00:53:56.820 | most of the time, provided you're not in maximum effort,

00:53:59.560 | you should be nasal breathing.

00:54:01.260 | Now, for a lot of people,

00:54:02.840 | nasal breathing during exercise is hard at first,

00:54:05.420 | but as you do it,

00:54:06.440 | because the sinuses have a capacity to dilate over time,

00:54:10.320 | you'll get better at it.

00:54:11.880 | The sinuses, if you haven't ever held a skull,

00:54:14.920 | because of my job as a neuroscientist,

00:54:17.640 | I've held a lot of skulls,

00:54:18.640 | taken a lot of brains out of a lot of skulls,

00:54:21.180 | teach neuroanatomy and have done that for, goodness,

00:54:23.760 | God knows how many species I've done that for,

00:54:26.420 | including human.

00:54:27.260 | But what the sinuses are is they're actually,

00:54:30.120 | what you've got are you've got these little portals

00:54:32.440 | in the bone that run up here and down here

00:54:35.640 | behind the nose and into the jaw.

00:54:37.760 | If you ever had a cold and your sinuses are stuffed up,

00:54:39.780 | you feel like you have congestion here and here

00:54:42.280 | and around your ears and in your cheeks and in your face.

00:54:44.560 | And that's because the sinuses are actually portals

00:54:47.780 | where the bones are fused together,

00:54:50.860 | kind of interdigitate like this,

00:54:52.760 | but they're lined, of course, with mucus membranes.

00:54:54.960 | And as you start to nasal breathe more,

00:54:57.060 | the nasal passages will start to dilate more.

00:54:59.220 | Don't worry, you're not going to get giant nostrils.

00:55:01.240 | But what's going to end up happening

00:55:02.680 | is you're going to have an easier time breathing

00:55:04.100 | through your nose just from waking.

00:55:06.180 | So my advice would be breathe through your nose

00:55:10.660 | while exercising, unless you're in maximum effort.

00:55:13.800 | Pretty soon, what you'll find is you actually can

00:55:16.240 | create more output than you would

00:55:18.020 | if you were breathing through your mouth.

00:55:19.520 | And of course, there are exceptions to this.

00:55:21.060 | If you're swimming, follow that breath protocol.

00:55:23.460 | For fighters and martial artists,

00:55:24.880 | there's reason to do the kind of exhale breathing

00:55:27.720 | through the mouth, the shh kind of thing.

00:55:29.600 | There are reasons to do that sort of thing

00:55:31.480 | for particular sports, but for most people

00:55:33.160 | who are kind of recreational athletes or exercisers,

00:55:36.060 | learn to be a nasal breather.

00:55:37.480 | It has positive cosmetic effects, it reduces apnea,

00:55:40.760 | it offloads more carbon dioxide, it increases lung capacity,

00:55:44.040 | it dilates the sinuses, and it prevents apnea in sleep.

00:55:48.440 | So unless you have severe apnea and you need the CPAP,

00:55:51.640 | becoming a nasal breather can have all sorts

00:55:53.740 | of positive effects by reducing cortisol,

00:55:55.880 | reducing apnea, and indirectly,

00:55:59.120 | raising testosterone and estrogen in the proper ratios.

00:56:02.720 | So this might seem kind of foundational and indirect,

00:56:05.080 | but when you go into the scientific literature,

00:56:07.260 | it comes through as one of the most powerful things

00:56:10.100 | that you can do that is zero cost,

00:56:13.320 | takes a little effort, but at zero cost,

00:56:15.560 | and it has all these positive effects across the board,

00:56:19.760 | both cosmetic and in sleep and hormonal, et cetera.

00:56:22.780 | So that's the first piece of behavioral advice.

00:56:25.680 | The second piece of behavioral advice

00:56:27.440 | relates to the viewing of light.

00:56:30.540 | And many of you have heard me talk about this before,

00:56:33.160 | and I'm not going to belabor the point

00:56:35.040 | that viewing bright light within the first hour of waking,

00:56:38.360 | whether or not it's from artificial light

00:56:39.680 | or ideally from sunlight,

00:56:40.960 | has these powerful effects on sleep and wakefulness.

00:56:44.060 | But we have to return to this if you want to understand

00:56:46.960 | how light can impact hormones,

00:56:49.000 | because hormones, light and dopamine

00:56:52.200 | have a very close-knit relationship,

00:56:54.020 | so much so that your light viewing behavior

00:56:57.400 | can actually have a direct effect

00:56:59.520 | on hormone levels and fertility.

00:57:01.720 | It can have a direct effect on hormone levels and libido.

00:57:05.360 | It can have a direct effect on hormone levels

00:57:07.980 | and your ability to heal quickly.

00:57:09.800 | And I'm not talking about shining light

00:57:11.320 | on particular injuries,

00:57:12.420 | that may or may not have positive effects.

00:57:14.520 | We can argue about that on a subsequent episode, it may,

00:57:18.820 | but what I'm talking about is viewing light with your eyes.

00:57:21.320 | So let's talk about that now

00:57:22.560 | because the scientific literature on this are robust

00:57:26.440 | and they extend back several decades,

00:57:28.400 | and yet I think most people don't really understand

00:57:30.920 | how powerful this relationship is

00:57:32.400 | between light, dopamine, hormones,

00:57:35.160 | and all the great things that the sex steroid hormones do

00:57:37.680 | when they're available in your body in the proper ratios.

00:57:40.980 | In order to understand the powerful effects

00:57:42.920 | that light can have on the sex steroid hormones,

00:57:45.740 | we need to understand seasonal breeding animals.

00:57:49.020 | Now, humans are not seasonal breeders,

00:57:51.160 | but if you understand the biology

00:57:52.800 | of how light impacts various neurotransmitters and hormones,

00:57:56.360 | you'll set yourself up for a deep understanding

00:57:58.280 | of what you should do with your light viewing behavior.

00:58:01.000 | So several species of animals,

00:58:03.640 | many species of animals, in fact,

00:58:05.600 | like rabbits and fox and various mustelids,

00:58:09.880 | like ferrets and ermines,

00:58:11.360 | change their pelage color across the seasons.

00:58:14.960 | This might be kind of a duh,

00:58:16.800 | but fox in winter are often white or light gray,

00:58:20.660 | and those same animals will be brown or darker colored

00:58:25.140 | in the summertime and spring months.

00:58:27.340 | Now, those same animals breed in the spring,

00:58:29.700 | and they shut down breeding.

00:58:31.380 | They actually shut down ovulation.

00:58:33.860 | They often shut down testosterone production

00:58:36.320 | in the winter months.

00:58:37.900 | So right now I'm just correlating color of fur

00:58:41.180 | with tendency to breed.

00:58:43.140 | Tendency to breed, as we know,

00:58:44.460 | is going to be related to the levels of sex steroid hormones,

00:58:47.920 | estrogen and testosterone.

00:58:50.620 | Now, why would these two things be linked?

00:58:53.280 | Well, it turns out that dopamine is the link between them.

00:58:57.880 | So dopamine has a precursor.

00:58:59.520 | That precursor is tyrosine,

00:59:01.640 | which is an amino acid, comes from food.

00:59:04.600 | And when dopamine levels are high, as I mentioned before,

00:59:06.960 | there's a tendency for more gonadotropin-releasing hormone,

00:59:10.240 | luteinizing hormone, follicle-stimulating hormone,

00:59:12.280 | all the hormones that come

00:59:13.240 | from the hypothalamic-pituitary axis

00:59:15.600 | and stimulate estrogen and testosterone release

00:59:18.360 | from the ovary and testes.

00:59:20.960 | Dopamine basically increases all of that.

00:59:24.500 | The precursor to dopamine is tyrosine,

00:59:28.660 | but the precursor to a lot

00:59:30.460 | of the melanin-producing elements of cells

00:59:33.300 | that give pigmentation, including for the hair,

00:59:36.500 | is tyrosine and tyrosinase, an enzyme.

00:59:41.280 | So yes, the same amino acid-based pathway

00:59:45.440 | and many of the same enzymes

00:59:47.760 | that are devoted to dopamine

00:59:50.420 | and dopamine-increasing the sex steroid hormones are devoted

00:59:54.480 | to giving pigmentation to the hair and skin.

00:59:57.420 | And this is why in the summer months, when days are longer,

01:00:02.940 | animals are breeding more.

01:00:05.280 | And this is also why in the winter months,

01:00:07.560 | when days are shorter, animals are breeding less.

01:00:11.640 | This is also why in humans, many people, not all,

01:00:15.720 | feel an elevation and mood in the spring and summer months

01:00:18.800 | because of the amount of sunlight they're getting

01:00:21.160 | is increased relative to the winter months.

01:00:24.380 | Now, some of you may be saying,

01:00:25.360 | "I love the fall, I love the winter."

01:00:27.400 | Sensitivity to light in these dopamine systems

01:00:29.860 | has a strong genetic component.

01:00:32.160 | So you go to some areas of the world,

01:00:33.440 | I have relatives who are Scandinavian,

01:00:36.080 | and in some areas of Scandinavia,

01:00:38.320 | people know that there's a kind of seasonal affective disorder

01:00:41.000 | that's kind of a seasonal depression,

01:00:42.720 | and people get sadder and more quiescent in the winter.

01:00:45.460 | There's actually less going out,

01:00:47.620 | and therefore there's less sexual behavior,

01:00:49.780 | there's less partying and things of that sort.

01:00:52.560 | But other people will say,

01:00:53.880 | "No, during the winter months, I feel great,

01:00:56.040 | and I love the holidays around winter," et cetera.

01:00:57.960 | So there's a lot of variation.

01:00:59.560 | But in general, the pathway is the following.

01:01:02.400 | Increased viewing of sunlight,

01:01:04.300 | and it has to be to the eyes, it's not to the skin,

01:01:06.900 | increased viewing of sunlight,

01:01:08.780 | increases dopamine levels in the brain,

01:01:11.180 | increased dopamine levels in animals and humans,

01:01:13.840 | increases the amount of these melanocytes

01:01:17.320 | and the activity of these melanin-producing cells,

01:01:20.780 | which give pigmentation to the skin and hair,

01:01:23.700 | and indirectly increase the amount

01:01:27.760 | of testosterone and estrogen

01:01:29.720 | and thereby reproductive behavior, feelings of wellbeing,

01:01:33.240 | social interactions, reductions, anxiety, et cetera,

01:01:36.360 | all of which should make sense

01:01:37.420 | based on what we've talked about already

01:01:39.540 | in terms of the biology

01:01:41.140 | and the impact of these steroid hormones

01:01:43.900 | on various aspects of the mind and body.

01:01:46.420 | So how does this translate to a protocol?

01:01:49.000 | This translates to the protocol of,

01:01:51.020 | if you want to optimize testosterone and estrogen,

01:01:54.380 | you need to get your light viewing behavior correct.

01:01:57.020 | It's not just about optimizing your sleep,

01:01:59.960 | which is also important,

01:02:01.000 | it's about getting sufficient amount of light in your eyes

01:02:03.740 | so you have sufficient levels of dopamine.

01:02:06.100 | So the simple protocols for that I've reviewed before,

01:02:09.100 | but it means getting anywhere from two to 10 minutes

01:02:11.220 | of bright light exposure in your eyes early in the day.

01:02:13.980 | It is not sufficient to do this with sunglasses

01:02:16.700 | unless you have to do that for safety reasons.

01:02:18.500 | It's fine to wear prescription lenses and contacts.

01:02:21.140 | If you can't get sunlight for whatever reason,

01:02:23.100 | you want to use bright artificial light,

01:02:24.900 | but that is absolutely critical

01:02:26.900 | for timing the cortisol release properly,

01:02:29.300 | limiting cortisol release to the early part of the day,

01:02:31.860 | getting increases in dopamine

01:02:33.380 | that are going to promote the production

01:02:35.460 | of testosterone and estrogen to healthy levels.

01:02:38.100 | The other aspect of light viewing behavior

01:02:39.800 | that's extremely important

01:02:41.340 | is to avoid bright light exposure to your eyes

01:02:45.500 | in the middle of the night.

01:02:46.620 | If you're viewing bright light in the middle of the night,

01:02:48.460 | you are suppressing dopamine release.

01:02:50.440 | If you're suppressing dopamine release,

01:02:52.180 | you are suppressing testosterone levels.

01:02:55.020 | So much so that I would wager

01:02:57.100 | that a major effect of sleep deprivation

01:03:00.820 | on reducing testosterone and estrogen

01:03:04.040 | is not necessarily because of the lack of sleep per se,

01:03:06.700 | it's because usually when people

01:03:08.140 | are not getting enough sleep,

01:03:09.440 | they're getting too much light in their eyes

01:03:11.560 | in the middle of the night as well.

01:03:13.620 | A study on this has not been completed yet,

01:03:16.660 | but there are two studies published in Cell and Neuron,

01:03:19.420 | both cell press journals, excellent journals,

01:03:21.540 | showing that viewing bright light with the eyes

01:03:23.780 | in the middle of the circadian night

01:03:26.380 | has a detrimental effect on dopamine

01:03:28.820 | and therefore has a detrimental effect

01:03:31.460 | on things like testosterone and estrogen.

01:03:33.740 | So you can't even begin to talk about supplements

01:03:36.160 | and other ways to optimize testosterone diet

01:03:38.460 | and its effects on testosterone and estrogen

01:03:40.180 | and fertility and reproductive behavior, et cetera,

01:03:43.020 | until you get your breathing right,

01:03:44.880 | until you get things like your light viewing behavior right.

01:03:48.420 | So bright light early in the day

01:03:49.940 | and throughout the day is great.

01:03:52.080 | View as much bright light, ideally sunlight, as you can,

01:03:55.140 | as much as you safely can.

01:03:56.600 | You obviously don't want to burn your retinas

01:03:58.740 | or damage your retinas,

01:03:59.580 | so never look at any light that's so bright

01:04:01.360 | it's painful to look at.

01:04:02.640 | But getting a lot of light in your eyes

01:04:04.260 | is not just about adjusting your sleep-wake rhythms,

01:04:06.600 | it's also about optimizing your sex steroid hormones.

01:04:09.560 | And avoiding bright light in the middle of the night

01:04:11.360 | is not just about not disrupting your sleep,

01:04:14.180 | it's also about optimizing the sex steroid hormones.

01:04:17.440 | And now that you understand a bit

01:04:19.220 | of how the sex steroid hormones work

01:04:20.540 | and how powerful they are for reducing anxiety

01:04:22.940 | and all these other effects,

01:04:24.720 | this should be straightforward to do,

01:04:26.680 | or hopefully it's inspired you

01:04:28.040 | to get your light viewing behavior

01:04:29.580 | and your breathing behavior correct.

01:04:31.560 | In fact, in thinking about tools,

01:04:33.880 | for many people that are suffering

01:04:35.340 | from low levels of estrogen if they want higher levels,

01:04:38.420 | or low levels of testosterone if they want higher levels,

01:04:41.340 | just getting the breathing and light viewing behavior,

01:04:44.520 | which will indirectly support sleep behavior,

01:04:48.360 | can be a huge and positive effect

01:04:51.500 | on levels of sex steroid hormones.

01:04:53.720 | I can already anticipate that in hearing this,

01:04:56.600 | you might wonder whether or not viewing light

01:04:59.000 | is going to, for instance, increase your testosterone a lot

01:05:02.480 | when in fact you want your estrogen increased,

01:05:04.720 | or it's going to increase your estrogen a lot

01:05:06.680 | when you want your testosterone increased.

01:05:09.420 | Everything I'm describing here is for people,

01:05:12.520 | regardless of chromosomal or gonadal background.

01:05:15.180 | So I'm trying to basically offer all this information

01:05:17.880 | in one swoop.

01:05:19.820 | But basically, if you're somebody who naturally has ovaries

01:05:23.960 | and has higher levels of estrogen than testosterone,

01:05:26.560 | then viewing bright light early in the day

01:05:28.920 | because of dopamine's effects

01:05:30.920 | is going to promote more estrogen

01:05:33.960 | and subtle increases in testosterone.

01:05:35.960 | Whereas if you're somebody who starts off

01:05:37.600 | with more testosterone and lower estrogen,

01:05:40.200 | so somebody presumably who has testes,

01:05:42.440 | or maybe you're supplementing with testosterone

01:05:44.360 | through other sources for whatever reason,

01:05:46.360 | bright light viewing is going to increase testosterone

01:05:49.440 | and estrogen in parallel,

01:05:51.320 | but you're still going to maintain

01:05:52.720 | the ratio of testosterone to estrogen.

01:05:54.600 | In short, you don't have to worry

01:05:56.060 | that you're going to increase the wrong hormone.

01:05:57.840 | This is all about optimizing the ratios of hormones

01:06:00.040 | that you already have.

01:06:01.800 | Okay, so we've talked about breathing.

01:06:03.380 | We've talked about light.

01:06:04.920 | Let's talk about a third element

01:06:07.280 | that there seems to be some excitement about lately

01:06:09.840 | for other reasons,

01:06:11.940 | but that can actually have some pretty profound influences

01:06:15.420 | on hormone levels, and that's heat and cold.

01:06:19.160 | So as always, rather than just offer a tool,

01:06:21.800 | I'm going to tell you the underlying science

01:06:24.040 | as it relates to naturally occurring phenomenon,

01:06:26.340 | because in understanding that

01:06:27.680 | and understanding the mechanism,

01:06:29.160 | you're going to be in a far better position

01:06:31.480 | to understand the tools and mechanisms

01:06:33.680 | and how you might want to adjust them for your own life.

01:06:36.720 | So now you understand the relationship

01:06:39.120 | between light, day length, dopamine, and hormone levels,

01:06:43.120 | and everyone should realize

01:06:45.520 | that temperature and day length are linked,

01:06:48.000 | and I'm sure as I say that,

01:06:49.060 | you're probably thinking, oh, of course.

01:06:51.120 | In summer, when there's more sunlight,

01:06:53.880 | days are longer, nights are shorter,

01:06:55.480 | in general, it tends to be warmer out,

01:06:57.400 | and in winter, when nights are longer, days are shorter,

01:06:59.760 | it tends to be colder out.

01:07:01.780 | And in the winter months,

01:07:03.760 | testosterone and estrogen tend to be lower in many animals

01:07:07.680 | and in humans, and in the summer months,

01:07:11.880 | because of the role of dopamine

01:07:13.360 | in promoting the sex steroid hormones,

01:07:15.960 | when days are longer and it's warmer,

01:07:18.800 | humans tend to make more estrogen and testosterone

01:07:21.800 | relative to the other months of the year.

01:07:24.220 | Now, these effects can be somewhat weak and modulated,

01:07:27.360 | as opposed to in seasonally breathing animals

01:07:29.800 | where they're really dramatic, okay?

01:07:32.120 | But the point is that temperature and day length

01:07:37.120 | and sunlight, those are all intimately related

01:07:40.180 | because of the systems that we evolved in, right?

01:07:42.780 | So before we had artificial light

01:07:44.280 | and artificial heating and artificial cooling,

01:07:46.720 | our biology evolved under systems where temperature,

01:07:49.840 | day length, and the hormones

01:07:52.080 | were correlated with one another.

01:07:54.120 | So nowadays, there's a lot of interest

01:07:56.060 | in using cold as a way to stimulate testosterone.

01:07:59.940 | This is mainly because in the sports community,

01:08:03.280 | in particular in the bodybuilding community,

01:08:05.520 | they are always seeking ways to maximize testosterone,

01:08:08.580 | dihydrotestosterone, keep estrogen to its minimum required

01:08:12.000 | to still have libido and still have skin elasticity,

01:08:15.060 | but also walk around with saran wrap skin,

01:08:17.480 | then all this kind of extreme stuff that happens there

01:08:20.520 | has led to a recent movement where, believe it or not,

01:08:23.640 | I heard this and I couldn't believe I went and checked,

01:08:25.800 | although I didn't buy them,

01:08:26.840 | that on Amazon, you can actually find,

01:08:30.000 | people have their literally underwear that have ice packs,

01:08:34.200 | or I think they're ice pack underwear,

01:08:35.800 | so that people are making themselves cold

01:08:38.280 | at the level of the gonads

01:08:39.620 | in order to try and increase testosterone and libido.

01:08:42.600 | Sounds pretty crazy, but believe it or not,

01:08:46.040 | that and things like ice baths and cold showers

01:08:48.760 | can have positive effects on the sex steroid hormones,

01:08:53.160 | both testosterone, mainly in males,

01:08:55.200 | and estrogen, mainly in females.

01:08:57.880 | And you might say, wait,

01:08:59.560 | I thought cold makes the reproductive axis

01:09:03.960 | kind of shut down a bit or reduces testosterone and estrogen,

01:09:07.260 | but it turns out it's not actually the cold

01:09:09.720 | that's having these effects in people.

01:09:11.720 | Things like the ice bath, cold showers, cold water swims,

01:09:15.160 | these ice underwear, whatever they are,

01:09:17.900 | can't believe that these actually exist, but they do exist.

01:09:21.880 | What happens is there's a rebound in vasodilation

01:09:25.240 | after cooling, so cooling causes vasoconstriction,

01:09:29.200 | and then after the cooling,

01:09:30.840 | there's a rebound vasodilation,

01:09:33.260 | and there's more infusion of blood into the gonads.

01:09:36.700 | There's also an effect that's neural.

01:09:39.440 | So let me explain how this works,

01:09:41.340 | because there are only a few studies on this,

01:09:43.480 | none of which looking at the frozen underwear,

01:09:45.180 | but that have looked at cold exposure

01:09:46.820 | and levels of androgens and estrogens,

01:09:49.040 | and it's kind of interesting.

01:09:50.600 | So you have to remember that the gonad,

01:09:53.840 | the ovaries and the testes are heavily vascularized.

01:09:57.540 | Remember, even at the level of the brain,

01:09:59.520 | GnRH, gonadotropin-releasing hormone,

01:10:01.760 | comes from neurons that, believe it or not,

01:10:03.960 | start off in your nose early in development,

01:10:06.120 | migrate into the hypothalamus, I'm not making that up,

01:10:08.360 | they started off in your nose, migrate into the hypothalamus.

01:10:10.920 | Those neurons extend processes,

01:10:13.660 | we call them axons, into the pituitary

01:10:16.600 | and release GnRH into the pituitary.

01:10:19.720 | There's a lot of vascularization within the pituitary,

01:10:22.380 | so now those hormones, or GnRH,

01:10:24.680 | can stimulate follicle-stimulating hormone,

01:10:27.820 | luteinizing hormone, which then are released

01:10:29.660 | and travel into the bloodstream.

01:10:31.660 | Then those hormones reach the ovary or testes,

01:10:36.480 | and they have to get into the ovary and testes.

01:10:39.480 | And the way they do that is through the vascular system.

01:10:43.120 | And people forget, but the vascular system

01:10:45.880 | and how constricted or dilated vessels are

01:10:49.800 | is controlled by neurons, right?

01:10:52.880 | This is, we discussed this during the discussion

01:10:54.960 | about stress in the stress episode,

01:10:57.260 | but it's well-known to neuroscientists

01:11:00.400 | that the best way to shut down neurons is to cool them.

01:11:04.300 | So there are a lot of examples of this

01:11:06.440 | in the scientific literature,

01:11:07.520 | but most people aren't aware of it

01:11:08.580 | 'cause you're not digging around

01:11:09.720 | in the methods section of these papers,

01:11:11.300 | but when we want to shut down neurons,

01:11:14.200 | we can do things like inject drugs

01:11:15.920 | that will do that, like lidocaine,

01:11:17.640 | the stuff that makes you numb at the dentist,

01:11:19.180 | or you can use different inhibitors.

01:11:20.800 | But one of the best ways to do it experimentally

01:11:22.960 | is to just cool neurons.

01:11:24.320 | When you make neurons cold,

01:11:26.600 | because there's a temperature dependence

01:11:28.280 | of when neurons can be active and when they can't,

01:11:30.600 | the neurons shut down.

01:11:32.320 | So the most plausible explanation for why cold exposure,

01:11:36.300 | either through one to 10-minute ice bath or cold shower

01:11:40.120 | or the ice underpants thing, would increase testosterone

01:11:43.640 | or increase estrogen, is that you're cooling the neurons

01:11:47.160 | that control vasoconstriction and vasodilation

01:11:50.440 | and shutting down the entry of blood,

01:11:55.240 | or at least reducing it, and hormones into the gonad.

01:11:58.960 | And then when the gonad and the surrounding area

01:12:02.200 | heats up again, you're getting a rebound hypervasodilation

01:12:06.320 | that delivers excessive levels of, not excessive,

01:12:09.760 | but increased levels of GnRH and other hormones

01:12:13.360 | and carriers and carrier proteins and so forth

01:12:16.300 | that would then stimulate the gonad

01:12:18.280 | to release more testosterone,

01:12:20.080 | or would stimulate the gonad to release more estrogen.

01:12:22.840 | That's the most plausible explanation I can come up with.

01:12:25.680 | There aren't a lot of studies looking at direct effects

01:12:28.220 | of temperature on the gonad,

01:12:29.760 | and it's going to be a difficult study

01:12:31.800 | to carry out in any case,

01:12:33.520 | because unless they were done in vitro in a dish,

01:12:35.940 | it's very hard to eliminate all the other things

01:12:38.040 | like vasoconstriction and vasodilation.

01:12:40.260 | Put simply, we don't know whether or not cold and heat

01:12:42.920 | directly affect the production of testosterone and estrogen.

01:12:47.640 | We only know that cold and heat can modulate those,

01:12:51.320 | probably through indirect mechanisms

01:12:53.060 | like controlling the amount of blood flow

01:12:54.980 | by way of shutting down or activating the neurons.

01:12:57.880 | Now, there's a lot of lore

01:12:59.340 | around heating up the gonads too much.

01:13:02.120 | There's actually a whole set of pseudoscience web pages

01:13:07.120 | out there saying, "Well, if you want a girl,

01:13:09.840 | "you should conceive the child at this room temperature,

01:13:12.580 | "and if you want a boy,

01:13:13.420 | "you should conceive the child at this room temperature."

01:13:15.640 | I don't think there's really

01:13:16.920 | any firm scientific evidence for that, for either one,

01:13:20.440 | but there's some interesting literature

01:13:22.980 | about temperature dependence of production of hormones,

01:13:26.280 | and I think that it probably relates to these mechanisms

01:13:28.720 | of vasodilation and neural control over vasodilation.

01:13:32.300 | And of course, excessively high heat is not good

01:13:35.400 | for the testes, for sperm production, or for sperm health.

01:13:39.000 | Sperm have all sorts of proteins in the cap,

01:13:41.140 | things like pentraxins and other things

01:13:43.080 | that cause them to swim faster

01:13:44.540 | when they're expressed properly and in the right locations,

01:13:47.240 | and heat actually alters the location

01:13:49.720 | and the function of a lot of those proteins.

01:13:51.480 | They're very heat sensitive,

01:13:52.960 | and so that's why excessive heat

01:13:54.360 | is truly not good for fertility,

01:13:56.780 | which may be independent of heat's roles

01:13:59.320 | in promoting estrogen or testosterone.

01:14:02.760 | Okay, so now we've talked about breathing,

01:14:04.640 | light, and temperature.

01:14:06.200 | We talked about parenthood.

01:14:07.520 | We talked about competition,

01:14:09.560 | and we talked about some pheromone effects.

01:14:11.900 | Now let's talk about particular forms of exercise

01:14:15.140 | and how they modulate the steroid hormones,

01:14:18.500 | and then we're going to talk about various supplements,

01:14:22.100 | both in reference to testosterone

01:14:24.140 | and in reference to estrogen.

01:14:26.040 | So now let's talk about how exercise in its various forms,

01:14:29.640 | weight training, endurance work, weight training to failure,

01:14:32.280 | or less intense weight training,

01:14:34.320 | can impact testosterone levels.

01:14:36.820 | But I want to remind you

01:14:37.960 | that we're talking about testosterone,

01:14:39.520 | both in males and females.

01:14:41.520 | And based on what you know from earlier in the episode,

01:14:44.480 | testosterone can have numerous positive effects

01:14:46.960 | in both males and females,

01:14:48.240 | provided they're in optimal range.

01:14:50.180 | So if you look on the web, people will say,

01:14:53.400 | oh, you know, testosterone is increased by weight training.

01:14:57.200 | You want to do big, heavy compound movements,

01:14:58.980 | squats and deadlifts and chins and things of that sort.

01:15:01.280 | But what about the scientific studies?

01:15:02.720 | Like what's the actual basis for this?

01:15:04.340 | 'Cause if you just take a step back

01:15:05.560 | and look at this from the perspective of a scientist,

01:15:07.640 | you'd say, okay, what is a squat?

01:15:09.640 | A squat is loading up a bunch of weights on a bar

01:15:12.240 | and then, you know, sitting down essentially

01:15:14.280 | and standing up over and over again.

01:15:16.120 | What's a deadlift?

01:15:17.840 | It's lifting heavy weights from the ground.

01:15:19.520 | Why would that increase testosterone, right?

01:15:22.000 | This is what's often not discussed in the weight training

01:15:24.540 | or even the exercise science community.

01:15:26.240 | What would actually stimulate the release of testosterone

01:15:30.000 | from the adrenals and/or testes?

01:15:31.840 | And which one is it, adrenals or testes or both?

01:15:34.480 | And that's often not discussed, but as a neuroscientist,

01:15:37.460 | this is the kinds of things we think about

01:15:38.740 | 'cause we think always that genes don't create behavior,

01:15:43.160 | immune systems don't know when to be activated,

01:15:45.320 | lungs don't know when to inhale or exhale,

01:15:48.220 | hearts don't know when to beat

01:15:49.520 | except for the information that it gets from neurons.

01:15:52.460 | The nervous system controls all of that.

01:15:55.040 | And so really the answer has to be in the neural system

01:15:59.720 | that's related to these particular types

01:16:02.200 | of weight-bearing exercises.

01:16:04.220 | So when you go into this literature,

01:16:07.020 | it's kind of hard to find real mechanism.

01:16:09.480 | You see a lot of effects.

01:16:10.720 | You'll hear things like androgen receptor content,

01:16:13.360 | meaning testosterone and its derivatives,

01:16:15.560 | receptor content following heavy resistance exercise.

01:16:18.360 | And you'll find some examples that, for instance,

01:16:20.760 | you know, they do muscle biopsies.

01:16:23.300 | They can actually see receptor increases

01:16:26.120 | looking at either high volume or low volume,

01:16:29.220 | really intense exercise.

01:16:30.560 | And you can find a lot of that,

01:16:31.960 | but not a lot of mechanism

01:16:33.520 | about how the nervous system would do this.

01:16:36.040 | And the reason you'd want to know how it can do it

01:16:38.240 | is that you could potentially build better protocols

01:16:41.880 | or figure out exactly what about these movements

01:16:45.400 | is triggering increases in androgen receptors

01:16:48.280 | and testosterone.

01:16:50.080 | So what's interesting is when you start digging

01:16:52.920 | into the more mechanistic studies,

01:16:55.320 | what you find is that heavy weight training,

01:16:58.360 | so this is weight training where the sets are done

01:17:02.200 | with anywhere from, you know, kind of one to eight rep range.

01:17:05.680 | So this translates differently

01:17:07.280 | depending on ratio of muscle fiber type and so forth,

01:17:10.000 | but where basically people are working at anywhere

01:17:12.240 | from like 70% to 95% of their maximum

01:17:15.360 | or sometimes even going right down

01:17:16.760 | to their one repetition maximum,

01:17:18.400 | really kind of, you know, max effort.

01:17:21.160 | What you find is that using the nervous system

01:17:25.440 | in a way in which they're moving heavy loads,

01:17:27.740 | so that I would translate to recruitment

01:17:30.020 | of high threshold motor units for you muscle physiologists.

01:17:33.320 | And there's a rule in muscle physiology

01:17:36.560 | about the neuron recruitment for moving muscles

01:17:39.360 | where you basically use the minimum number of motor units

01:17:42.200 | of neurons to activate muscle as you possibly can.

01:17:45.160 | As loads increase, you have to recruit more and more neurons.

01:17:48.440 | You always hear about recruiting muscle fibers,

01:17:50.520 | but really it's recruiting more neurons

01:17:52.240 | to recruit more muscle fibers.

01:17:55.040 | And what you find is that heavy weight training,

01:17:58.240 | but not weight training to failure

01:18:00.460 | where completion of a repetition is impossible

01:18:03.740 | leads to the greatest increases in testosterone.

01:18:06.520 | Now, I'm sure there are a bunch of exercise jockeys out there

01:18:08.940 | that are going to come at me with a bunch of things

01:18:10.880 | where, oh yeah, but high volume and this

01:18:13.140 | and training to failure and that, sure.

01:18:16.600 | If you're willing to kind of put things side by side,

01:18:19.360 | adjust for exogenous testosterone treatment

01:18:22.480 | and all the rest, which was done in these studies,

01:18:25.040 | what you find in general is that weight training

01:18:28.880 | with heavy loads, so anywhere from one rep maximum

01:18:32.100 | to somewhere in the six to eight repetition range

01:18:35.860 | in males or females increases testosterone significantly.

01:18:39.840 | And it does it for about a day, sometimes up to 48 hours.

01:18:44.100 | And the studies that I found,

01:18:45.580 | which seem to hold the most rigor or weight

01:18:48.780 | based on where they're published

01:18:49.920 | as opposed to being published in the journal,

01:18:51.240 | never heard of it.

01:18:52.080 | They're published in good quality

01:18:53.580 | exercise physiology journals.

01:18:57.280 | For instance, the paper by Ratames, R-A-T-A-M-E-S-S, et al,

01:19:02.280 | which was published in 2005,

01:19:06.420 | which talks about modulations in androgen receptor content

01:19:09.420 | after heavy resistance exercise,

01:19:10.920 | looks at going to failure, not to failure.

01:19:13.560 | The work of Sciardo et al, published in 2006,

01:19:18.560 | differential effects of strength training

01:19:20.300 | leading to failure versus not failure

01:19:21.880 | on hormonal responses, strength, and power gains.

01:19:24.760 | There are a lot of studies here,

01:19:25.960 | and I will certainly put the links to these in the caption.

01:19:29.500 | Many of these actually include Duncan French,

01:19:31.800 | who runs the UFC Training Center,

01:19:34.160 | who I've had the privilege of meeting

01:19:35.680 | and discussing some of this with before,

01:19:38.180 | as well as other authors, of course.

01:19:39.880 | But they all point to the fact that there's something

01:19:41.920 | about the engagement of the neurons

01:19:44.520 | that recruit high threshold motor units in muscle

01:19:48.520 | when moving heavy loads, but not to failure,

01:19:51.320 | that has to provide some sort of feedback signal

01:19:54.280 | either to the gonad to produce more testosterone

01:19:56.720 | or is increasing the activity of receptors in the body.

01:20:01.600 | Now, why do I say that?

01:20:03.200 | Well, this is the puzzle, right?

01:20:05.360 | How is it that a particular movement,

01:20:06.880 | just like how is it that interacting with your child

01:20:09.300 | is increasing or decreasing testosterone?

01:20:11.740 | This is the kind of fundamental question

01:20:13.240 | at the mechanistic level.

01:20:14.720 | And we answered the question for child rearing.

01:20:17.080 | It has probably something to do with smell and pheromones,

01:20:19.660 | although I'm sure there are other cues as well.

01:20:21.760 | But there's clearly a influence of hard work

01:20:26.760 | at the neural level and then at the muscular level

01:20:31.120 | for increasing testosterone.

01:20:33.120 | And there's also clearly an effect of working too hard

01:20:37.400 | and presumably increasing cortisol too much,

01:20:40.280 | although I'm speculating there,

01:20:41.800 | in terms of reducing testosterone.

01:20:44.320 | And so the reason we're getting nitty gritty about this

01:20:46.880 | is because ultimately we'd really like to understand

01:20:48.840 | what are the optimal protocols?

01:20:50.240 | You know, out there in the literature you hear,

01:20:52.100 | move heavy objects to increase testosterone.

01:20:54.480 | Some of that will be converted

01:20:55.560 | to the more powerful androgen, DHT,

01:20:57.500 | by 5-alpha reductase, et cetera.

01:20:59.680 | But we really don't understand yet

01:21:01.980 | how these particular behaviors increase testosterone

01:21:04.720 | and whether or not it's doing that

01:21:06.060 | by modulating the receptors

01:21:07.620 | or it's modulating testosterone release directly,

01:21:09.760 | presumably testosterone release directly

01:21:11.600 | and sensitivity of the receptors.

01:21:13.640 | That's what most of the muscle physiology studies

01:21:15.680 | that I was able to find point to.

01:21:17.480 | But this basically boils down

01:21:18.800 | to a particular set of protocols

01:21:20.500 | where if you want to increase testosterone

01:21:22.640 | for whatever reason,

01:21:24.200 | that weight training with heavy loads,

01:21:26.800 | but not to failure seems to be the best supported,

01:21:30.340 | at least scientifically supported solution to that.

01:21:33.380 | Now, it may not raise your testosterone levels

01:21:35.320 | as high as you want,

01:21:36.400 | but it's definitely taking things in the correct direction.

01:21:39.660 | Now, many of you might be endurance athletes

01:21:42.020 | or also enjoy exercise besides heavy weight-bearing exercise.

01:21:46.880 | And there are several studies exploring

01:21:49.280 | whether or not endurance activity

01:21:52.460 | can increase or decrease androgen levels,

01:21:55.800 | and whether or not you combine

01:21:57.240 | endurance activity and weight training,

01:21:59.120 | whether or not that has any effect

01:22:00.680 | if you do the endurance activity first or second.

01:22:03.760 | And the takeaway from all of this

01:22:06.040 | was that endurance activity, if performed first,

01:22:09.880 | leads to decreases in testosterone

01:22:12.660 | during the weight training session,

01:22:14.520 | as compared to the same weight training session done first,

01:22:17.180 | followed by endurance activity.

01:22:18.520 | In other words, if you want to optimize testosterone levels,

01:22:21.420 | it seems to be the case that weight training first

01:22:23.900 | and doing cardio type endurance activity afterward

01:22:27.380 | is the right order of business.

01:22:29.320 | Now, when these are done on separate days,

01:22:30.960 | it doesn't seem to have an effect.

01:22:32.800 | They showed no statistical interaction.

01:22:35.120 | But it seems that if you're going to do these

01:22:37.020 | in the same workout episode,

01:22:39.200 | that it's move heavy loads first,

01:22:41.420 | then do cardiovascular exercise.

01:22:43.880 | So there's a little bit of data looking specifically

01:22:46.400 | at how endurance exercise impacts testosterone

01:22:49.560 | and its derivatives.

01:22:50.560 | And it's very clear that high-intensity interval training,

01:22:53.160 | sprinting, et cetera,

01:22:54.360 | which somewhat mimics the neural activity

01:22:57.160 | that occurs while moving heavy weight loads,

01:23:00.060 | is going to increase testosterone.

01:23:02.120 | There's ample evidence for that in the literature.

01:23:04.800 | And that endurance exercise that extends beyond 75 minutes

01:23:09.560 | is going to start to lead to reductions in testosterone,

01:23:12.000 | presumably by increases in cortisol.

01:23:14.240 | But of course, the intensity of the exercise

01:23:17.800 | is going to be important too.

01:23:19.560 | No one ever, I don't think anyone really believes

01:23:21.860 | that hiking for the three hours

01:23:23.160 | is going to reduce your testosterone.

01:23:25.240 | Whereas I think if one were to go out

01:23:27.400 | and run hard for three hours,

01:23:29.320 | that you can imagine there'd be reductions in testosterone

01:23:31.660 | by way of increases in cortisol.

01:23:34.560 | And so while this area certainly needs more research,

01:23:37.600 | it's pretty clear that limiting the endurance exercise

01:23:40.140 | to 75 minutes or less, not making it too intense,

01:23:43.100 | is one way to keep cortisol from going through the roof.

01:23:46.660 | But I've talked on previous episodes,

01:23:48.240 | and there are a lot of others who have talked out there

01:23:50.020 | about how to clamp cortisol,

01:23:51.380 | how to keep cortisol more reduced.

01:23:53.540 | This is also one of the reasons why you can imagine

01:23:56.460 | that various individuals, either for competition

01:23:59.080 | or just for their own purposes,

01:24:00.860 | rely on testosterone therapy, exogenous testosterone,

01:24:03.980 | not just for weight training, but for endurance exercise.

01:24:07.500 | So this is one of the reasons why every once in a while,

01:24:09.740 | professional cyclists will get popped

01:24:11.260 | for performance in hectic drugs, I mean, they'll get caught.

01:24:14.020 | And it's not just that they're increasing red blood cells

01:24:16.620 | through EPO and things of that sort.

01:24:18.500 | Oftentimes they're also taking testosterone,

01:24:20.540 | not because they want to be large

01:24:22.540 | or have massively hypertrophied muscles,

01:24:24.960 | but because they're injecting testosterone,

01:24:28.060 | they don't have to worry about

01:24:29.220 | cortisol-induced reductions in testosterone.

01:24:31.780 | They can just clamp or keep their testosterone levels high.

01:24:34.380 | Not something I'm recommending,

01:24:35.780 | but I'm just justifying the rationale

01:24:38.020 | for why an endurance athlete would want to do that at all.

01:24:41.180 | So now let's switch over to talking about estrogen.

01:24:45.060 | So there are many people who are trying

01:24:46.580 | to optimize their estrogen levels.

01:24:48.760 | And one of the places where this shows up a lot,

01:24:50.780 | and I get a lot of questions about, is menopause.

01:24:53.580 | So menopause, as I mentioned earlier,

01:24:55.440 | is this fairly massive reduction in the amount of estrogen

01:24:59.860 | that is circulating in one's blood,

01:25:01.900 | mainly because the ovary is now depleted

01:25:05.900 | of some estrogen production of its own,

01:25:08.020 | the eggs are not being produced,

01:25:09.720 | they've been depleted, et cetera.

01:25:11.980 | So menopause is characterized by a variety of symptoms.

01:25:15.620 | And it's multifaceted,

01:25:17.780 | probably deserves an entire episode on its own,

01:25:20.060 | but things like hot flashes, things like mood swings,

01:25:23.300 | things like headaches, in particular, migraine headaches.

01:25:26.600 | There can be a lot of brain fog.

01:25:28.300 | It can be very, very disruptive for people.

01:25:30.500 | Now you sometimes hear about andropause,

01:25:32.260 | which is thought to be the kind of analog to menopause,

01:25:35.120 | but menopause has certain characteristics

01:25:37.400 | that make it a very robust phenomenon for most women.

01:25:42.400 | Whereas for men,

01:25:44.620 | andropause is going to sometimes happen, sometimes won't.

01:25:47.540 | In fact, without going into the details

01:25:49.580 | of the graphs and the data,

01:25:51.860 | it's very clear, as I mentioned earlier,

01:25:53.580 | that some men maintain levels of circulating androgens

01:25:57.780 | that are quite high, even as similar as they were in puberty

01:26:00.900 | and their teen years and 20s,

01:26:02.600 | well into their 60s, 70s, and 80s,

01:26:04.660 | if they're optimizing a lot of other things,

01:26:06.540 | and probably genetics plays a role as well,

01:26:09.180 | whereas some males won't,

01:26:10.920 | but within the female population

01:26:13.660 | or population of individuals that have ovaries,

01:26:16.320 | there's a very stereotyped and characteristic reduction

01:26:20.060 | in estrogen levels as the number of eggs becomes depleted,

01:26:23.880 | and that's what we think of as menopause.

01:26:26.440 | So what are the various things

01:26:28.420 | that one can do for menopause?

01:26:30.000 | Well, one of the most common ones

01:26:32.620 | is that physicians will prescribe supplemental estrogen.

01:26:36.020 | So this is hormone therapy

01:26:37.780 | where somebody takes either their oral estrogen

01:26:39.860 | or they'll use a patch or a pellet,

01:26:42.060 | some way to secrete estradiol into the system,

01:26:45.460 | and that has varying success depending on the individual.

01:26:49.320 | Some people respond very well to it.

01:26:51.000 | Other people really have challenges with it,

01:26:53.260 | and there are a lot of side effects associated with it

01:26:55.340 | for some people, not others.

01:26:57.620 | In addition,

01:26:58.860 | there's a concern always about supplementing estrogen

01:27:01.860 | when there's a breast cancer background in the family,

01:27:06.160 | or there's concern about breast cancer for any reason,

01:27:08.220 | because a lot of those cancers are estrogen dependent,

01:27:11.100 | and that's why drugs like tamoxifen and anastrozole

01:27:15.180 | and drugs that block either aromatase

01:27:18.040 | or block, excuse me, estrogen receptors directly

01:27:21.260 | were initially developed.

01:27:23.020 | You see them a lot on the internet,

01:27:24.560 | again, for all the sports folks

01:27:27.380 | who are trying to increase testosterone and reduce estrogen,

01:27:30.260 | but remember, those drugs were initially developed

01:27:32.400 | as ways to prevent estrogen binding

01:27:36.040 | to the estrogen receptor as cancer treatments.

01:27:39.140 | So I want to be very clear, and I've said this many times,

01:27:41.700 | we always put in the caption of each episode, of course,

01:27:44.780 | that I'm not a physician, I'm not an MD,

01:27:47.220 | I don't prescribe anything, I'm a professor,

01:27:48.820 | I profess things, I'm here to translate

01:27:50.300 | the scientific literature and point to

01:27:51.900 | what might be some useful avenues for exploration,

01:27:54.720 | but this is just for information purposes.

01:27:56.300 | You should definitely talk to your doctor

01:27:58.300 | about anything that I'm talking about now,

01:28:00.120 | or in any episode for that matter.

01:28:02.380 | So if you look at the literature on menopause

01:28:06.220 | outside of just standard estrogen therapy,

01:28:10.120 | there are some very interesting compounds out there

01:28:12.900 | that have been used and that are supported

01:28:15.180 | by quality peer-reviewed studies.

01:28:17.420 | And again, I'll refer you once again

01:28:19.420 | to this amazing website, examine.com,

01:28:21.700 | where you can put in essentially any condition

01:28:24.300 | or any supplement and it will point you

01:28:25.720 | to the human effect matrix, not animal studies,

01:28:29.420 | but human studies that have explored these things.

01:28:32.180 | Now, there are a huge variety of them here,

01:28:34.340 | so I won't go into all of them,

01:28:35.840 | but some of the pro-estrogenic compounds

01:28:38.840 | that have been shown to be powerful

01:28:42.200 | in the context of menopause, as well as other conditions

01:28:46.300 | where estrogen is lower than one would like,

01:28:48.960 | include a description and some of the literature,

01:28:51.320 | I'll get into this in a moment,

01:28:52.380 | of something like black cohosh,

01:28:54.920 | I think that's the correct pronunciation,

01:28:56.560 | it's literally the word black and then C-O-H-O-S-H.

01:29:00.960 | And it's very interesting,

01:29:02.640 | there are 13 peer-reviewed studies

01:29:05.820 | that have reached prominence

01:29:08.380 | in the kind of commercial landscape

01:29:10.060 | where this substance, black cohosh,

01:29:12.540 | has been promoted as a way to increase estrogen.

01:29:15.120 | Turns out that the effects are consistent,

01:29:18.320 | but are fairly minor, fairly minor increases in estrogen.

01:29:22.260 | So it does seem to be a real effect,

01:29:25.080 | it is significant over the placebo effect,

01:29:27.980 | but there's also a significant placebo effect

01:29:30.920 | in some of these studies as well.

01:29:32.700 | So what's interesting when you look at these studies

01:29:35.700 | is that many of them were carried out

01:29:38.040 | over a period of six plus months,

01:29:40.400 | they're double-blind studies, et cetera,

01:29:42.440 | and almost all of them led to modest increases in estrogen

01:29:46.820 | and modest decreases in menopause-related symptoms.

01:29:52.240 | Now, a few additional details about these studies,

01:29:56.240 | they were generally carried out on women age 45 to 64.

01:30:00.580 | In some cases, they look specifically at women

01:30:03.320 | that were clinically obese or overweight,

01:30:05.160 | although not always.

01:30:07.040 | The subject size pools are pretty big,

01:30:09.500 | anywhere from 50 to 87,

01:30:12.080 | these are decent size, 132 subjects, et cetera.

01:30:16.080 | So these look to be like quality studies,

01:30:18.180 | and they basically point to the fact

01:30:19.360 | that black cohosh can have a modest effect

01:30:22.560 | in improving menopause symptoms.

01:30:25.040 | The other one is Panax ginseng, so P-N-A-X, ginseng,

01:30:30.040 | has been shown to decrease some symptoms

01:30:33.360 | associated with menopause, mostly related to libido,

01:30:37.080 | although the other effects were unreliable.

01:30:40.240 | Other things like maca,

01:30:41.720 | which is known to increase dopamine actually,

01:30:43.780 | had minor effects,

01:30:45.400 | things like, the names here are a little hard to pronounce,

01:30:48.000 | so forgive me, things like Valeriana officionalis

01:30:52.980 | has shown that there can be some improvement

01:30:55.820 | in the hot flash symptoms

01:30:57.440 | and some of the insomnia associated with that,

01:30:59.360 | so that might be worth exploring,

01:31:01.200 | again, discuss with your doctor,

01:31:02.720 | but these were both 100 subject plus,

01:31:05.980 | age 45 to 64 individuals,

01:31:09.400 | double-blind placebo-controlled studies

01:31:11.520 | that showed significant but modest effects.

01:31:14.640 | There was one substance in the gallery of the compounds

01:31:19.640 | that was looked at

01:31:21.840 | that turns out to be particularly interesting,

01:31:24.480 | and this one is also particularly difficult to pronounce,

01:31:27.560 | and it's Puraria mirifica,

01:31:32.000 | so I'm going to spell this out for you.

01:31:33.780 | It's P-U-E-R-A-R-I-A,

01:31:38.780 | Puraria mirifica,

01:31:42.640 | M-I-R-I-F-I-C-A,

01:31:46.340 | and there are four studies on this compound

01:31:49.100 | that show in every case it to be very potent,

01:31:53.260 | in fact, comparable to estrogen therapy,

01:31:56.080 | estrogen replacement therapy,

01:31:57.920 | in reducing the symptoms of menopause,

01:31:59.760 | so this was pretty striking

01:32:01.240 | because when you go through these studies

01:32:02.600 | and you look again that they seem to be

01:32:04.600 | pretty well-controlled as far as I could tell,

01:32:08.740 | and they explored a pretty wide subject pool,

01:32:12.560 | and it seems that every single one of these studies,

01:32:16.140 | when looking side-by-side at Puraria mirifica,

01:32:21.140 | which is also called,

01:32:22.840 | now this is really hard to pronounce,

01:32:24.120 | quaocuracao,

01:32:26.360 | I guess that's the name that they use in various countries,

01:32:30.360 | that it was comparable to estrogen replacement therapy,

01:32:33.920 | so I mention this because a lot of people contacted me

01:32:36.900 | and said, "What about the insomnia in menopause?

01:32:39.080 | "What about the headaches in menopause?"

01:32:41.120 | Now, I'm not suggesting you run out

01:32:42.600 | and immediately start taking any of these compounds.

01:32:44.340 | Please talk to your doctor.

01:32:46.180 | Any hormone-related compound is a serious consideration

01:32:50.640 | because of the relationship to breast cancers,

01:32:53.160 | but just in general, these compounds are,

01:32:55.420 | estrogen and testosterone are exceedingly powerful

01:32:57.760 | in terms of controlling our mental and physical states,

01:33:01.200 | and so you want to approach them with caution,

01:33:03.520 | but I thought that that one in particular was interesting

01:33:06.400 | and for which there are quite a few PubMed-documented,

01:33:10.640 | peer-reviewed studies in quality journals.

01:33:13.320 | Okay, so now let's talk about

01:33:14.520 | the role of specific compounds,

01:33:16.320 | some of which, many of which,

01:33:17.840 | can be taken in supplementation form

01:33:20.040 | or extracted from diet and nutrition

01:33:22.520 | in order to optimize sex steroid hormones,

01:33:25.600 | and again, I just want to emphasize

01:33:27.640 | that I'm not suggesting anyone take anything

01:33:29.680 | or stop taking anything.

01:33:31.000 | This is purely for informational purposes,

01:33:33.040 | but some of the data on these

01:33:34.440 | is quite striking and impressive.

01:33:39.240 | It's very clear that certain collections of nutrients

01:33:44.120 | are useful for promoting testosterone

01:33:47.400 | and estrogen production in their proper ratios,

01:33:50.560 | and those things are what I would call

01:33:52.880 | the sort of usual suspects.

01:33:54.780 | Vitamin D, which is important

01:33:56.600 | for so many biological functions,

01:33:58.760 | including endocrine functions,

01:34:00.480 | zinc, magnesium, et cetera,

01:34:04.000 | and if you want to look into this more deeply

01:34:06.320 | and you want to understand exactly

01:34:07.600 | what the negative effects are of not having sufficient zinc,

01:34:10.240 | magnesium, and what those levels might actually be,

01:34:13.320 | there's a paper that's available.

01:34:14.680 | You can go on PubMed.

01:34:16.560 | I can't pronounce this last name.

01:34:18.000 | I'm sorry.

01:34:19.240 | It looks to me like Wrozosek,

01:34:21.200 | but it's W-R-Z-O-S-E-K.

01:34:25.060 | I hope I didn't butcher that too badly.

01:34:27.820 | Wrozosek et al., 2020,

01:34:30.440 | in "Endocrinology and Metabolism Review."

01:34:33.040 | So there's a recent paper in a good peer-reviewed journal.

01:34:35.940 | It talks mainly about how

01:34:38.120 | the hypothalamic-pituitary-adrenal axis

01:34:41.480 | and the sex steroid hormones are negatively impacted

01:34:44.880 | by deficiencies in magnesium,

01:34:47.400 | deficiencies in vitamin D, and deficiencies in zinc.

01:34:50.080 | However, that doesn't point to the levels

01:34:53.280 | that one should take in order to optimize.

01:34:56.580 | So it doesn't say take X amount of zinc

01:34:58.760 | or X amount of magnesium or X amount of vitamin D.

01:35:01.180 | For that information,

01:35:02.920 | because it's so context-dependent

01:35:05.800 | and individual-dependent,

01:35:07.200 | I highly recommend you go to examine.com.

01:35:09.460 | You can put in zinc or magnesium or vitamin D,

01:35:11.660 | and they will give you ranges of dosages

01:35:14.060 | that are supported by specific studies.

01:35:15.880 | Again, that information is completely free to you,

01:35:18.780 | and it's very useful in figuring that out.

01:35:22.100 | I personally have supplemented

01:35:23.880 | with zinc, magnesium, and vitamin D for years,

01:35:26.880 | but many other people do that as well.

01:35:28.360 | And the question is always how much?

01:35:29.660 | And that's why I'm a proponent of getting blood work done,

01:35:32.220 | because that's how you know whether or not

01:35:33.440 | your androgen levels, as well as things

01:35:35.920 | like vitamin D levels, et cetera, are sufficiently high.

01:35:39.240 | So the takeaway from these studies,

01:35:40.760 | looking at what deficiencies cause

01:35:43.260 | in terms of deficits in testosterone and estrogen,

01:35:45.820 | really point in the direction of,

01:35:47.700 | make sure you're getting adequate zinc, magnesium, and D3,

01:35:50.580 | unless you want these steroid hormone levels

01:35:53.360 | to be reduced for whatever reason.

01:35:55.260 | One of the things that's been shown time and time again

01:35:57.680 | to have very negative effects on sex steroid hormones,

01:36:00.920 | testosterone mainly in men, estrogen mainly in women,

01:36:04.360 | is opioids.

01:36:06.520 | There's this whole issue, of course, of the opioid epidemic.

01:36:10.480 | It's deserving of an entire episode

01:36:11.920 | where you're going to talk about that

01:36:13.580 | with experts in addiction

01:36:15.880 | and people that treat pain and so forth.

01:36:19.160 | But the opioids dramatically reduce levels

01:36:23.500 | of testosterone and estrogen,

01:36:25.480 | and they do that mainly by disrupting the receptors

01:36:29.500 | on gonadotropin-releasing hormone neurons,

01:36:31.780 | these neurons within the hypothalamus

01:36:33.320 | that communicate to the pituitary.

01:36:34.960 | And in fact, people that take large amounts of opioids

01:36:38.240 | or even take low levels of opioids for long periods of time

01:36:41.440 | will develop all sorts of endocrine syndromes.

01:36:44.000 | That's been shown over and over again.

01:36:45.860 | Gynecomastia or male breast development in males,

01:36:48.720 | disruptions to the ovary in females,

01:36:51.120 | it's really a quite terrible situation.

01:36:53.660 | So excessive opioids are very problematic

01:36:58.160 | for sex steroid hormones.

01:36:59.540 | I don't think anyone will have any trouble

01:37:02.020 | finding any literature on that.

01:37:03.140 | You can just go into PubMed,

01:37:04.100 | you can put opioids, testosterone or opioids, estrogen,

01:37:09.060 | but the major effect is actually way up in the hypothalamus

01:37:11.840 | to shut down the production of GnRH,

01:37:14.000 | the very hormone that stimulates

01:37:15.760 | testosterone and estrogen release.

01:37:17.960 | Now there's an entire industry devoted to supplements

01:37:21.480 | and various things that people can take

01:37:22.880 | to increase testosterone,

01:37:24.220 | some of which have scientific data to support them,

01:37:27.580 | some of which do not,

01:37:29.140 | and some of which have anecdotal support

01:37:31.600 | and some of which do not.

01:37:33.300 | This ranges so broadly.

01:37:35.020 | I mean, things like the material off deer antlers,

01:37:38.760 | which is high in supposedly IGF-1,

01:37:41.340 | which is in the growth hormone pathway,

01:37:43.740 | all the way to actual consumption of bull testes.

01:37:48.640 | You can go on Amazon right now,

01:37:50.160 | I certainly don't suggest that you do this,

01:37:51.000 | and you can actually buy ground up testes from cows.

01:37:56.500 | And you can consume those.

01:37:59.420 | Now, a lot of that's going to be broken down in the gut.

01:38:01.260 | I'm certainly not suggesting you do that,

01:38:02.900 | but just to point out, this is a huge and vast literature,

01:38:06.080 | and it actually dates back hundreds of years,

01:38:08.040 | even though testosterone wasn't discovered that long ago

01:38:12.260 | as a specific hormone molecule

01:38:14.580 | and characterized and then resynthesized,

01:38:18.020 | it has a huge industry

01:38:20.100 | because of the powerful effects that it has.

01:38:22.400 | Likewise with estrogen,

01:38:23.760 | the development of the birth control pill

01:38:25.540 | was only made possible by understanding the structure

01:38:28.140 | of estrogen and estradiol,

01:38:29.980 | and we're going to talk all about birth control

01:38:31.660 | and how it works and its influence on various other pathways

01:38:35.020 | in a future episode.

01:38:36.460 | But there are these supplement compounds

01:38:38.780 | that are supported by the scientific literature

01:38:41.800 | in terms of their ability to adjust androgens,

01:38:45.380 | things like testosterone and dihydrotestosterone.

01:38:48.340 | One of the ones that has really good evidence for it

01:38:50.940 | is creatine.

01:38:53.000 | It's very clear that something about creatine,

01:38:55.900 | although the mechanism isn't exactly clear,

01:38:58.520 | either increases 5-alpha reductase

01:39:01.300 | or makes the testosterone molecule more susceptible

01:39:04.460 | to certain enzymatic reactions

01:39:07.220 | that leads to increases in DHT.

01:39:09.300 | DHT, dihydrotestosterone, as I mentioned,

01:39:12.220 | the previous episode has this dramatic role

01:39:14.660 | in creating a kind of masculinization

01:39:17.700 | of the brain prenatally.

01:39:19.100 | It also defines the primary sex characteristic

01:39:22.640 | of the growth of the penis, et cetera,

01:39:24.540 | and beyond infancy and early childhood and later in life,

01:39:29.160 | it has powerful effects in creating balding

01:39:31.860 | and beard growth, et cetera,

01:39:33.020 | and it has a much higher affinity for the androgen receptor

01:39:36.740 | than does testosterone.

01:39:39.180 | So creatine can increase DHT,

01:39:42.040 | which means that if you take creatine

01:39:45.020 | and you're very DHT susceptible,

01:39:47.500 | then you might experience some hair loss.

01:39:49.660 | This has been heavily debated.

01:39:50.820 | Does creatine cause baldness?

01:39:52.260 | It's going to depend.

01:39:53.100 | It's going to depend on how much 5-alpha reductase you have

01:39:55.560 | and how prone to hair loss you are.

01:39:58.020 | Some people can take creatine without any problem

01:40:00.840 | in terms of hair loss.

01:40:01.680 | Some people cannot.

01:40:02.700 | They start losing their hair to levels

01:40:05.080 | that at least for them aren't comfortable.

01:40:07.960 | There are a few other things that can increase testosterone,

01:40:10.520 | and it has to do with the way that testosterone exists

01:40:13.780 | in its free and its bound form.

01:40:16.040 | So testosterone, the molecule is kind of total testosterone.

01:40:20.840 | That's usually what's measured.

01:40:21.840 | This is the kind of levels

01:40:23.160 | that are typically thrown around

01:40:24.260 | of anywhere from 300 to 900 being the kind of natural range,

01:40:27.600 | and then super physiological getting up into 1200, 1600 range.

01:40:32.020 | But testosterone isn't just roaming around free in the blood,

01:40:36.400 | at least most of it isn't.

01:40:37.960 | Most of it is bound to either sex hormone-binding globulin,

01:40:41.520 | SHBG, or to albumin.

01:40:44.480 | They're needed as transporters to get testosterone

01:40:47.440 | into cells so that testosterone can have its effects

01:40:49.920 | on gene expression as well as other pathways

01:40:53.280 | within the cells.

01:40:54.620 | So people talk about that the level of free testosterone

01:40:58.400 | is really what's important,

01:40:59.540 | and that you want to optimize free testosterone.

01:41:01.900 | That's a little bit of a tricky statement.

01:41:03.800 | That's kind of like, it's true,

01:41:07.520 | and yet it's not really reflective

01:41:10.560 | of a thorough understanding

01:41:11.800 | of how these binding globulins work.

01:41:14.400 | Remember, these binding globulins aren't there

01:41:16.040 | to soak up all your testosterone just to make it hard

01:41:18.200 | for you to free up testosterone and make gains in the gym

01:41:21.880 | or whatever it is, or have increases in libido.

01:41:24.160 | They're there to actually transport testosterone

01:41:26.440 | to specific tissues, to shuttle them to specific tissues,

01:41:30.000 | and to set the rate of bound and unbound testosterone

01:41:34.000 | so that it's not all unbound at once.

01:41:36.520 | And it's always interesting to look in the literature

01:41:39.280 | and see how everyone wants to free up their testosterone

01:41:41.940 | so that it can work.

01:41:42.780 | But sex hormone-binding globulin can bind up

01:41:46.840 | too much testosterone to the point

01:41:48.360 | where it's having negative effects on libido

01:41:50.360 | or on muscle growth and fat loss and things of that sort.

01:41:53.300 | This is true in males and females.

01:41:55.160 | Or it can be doing exactly what it's supposed to do,

01:41:58.520 | which is shuttling testosterone to the proper tissues

01:42:01.320 | and organs where it has all these effects,

01:42:02.880 | including the brain.

01:42:04.280 | So there are supplements, in particular, Tonga Ali,

01:42:09.280 | which has this other name.

01:42:11.520 | It's something I've called Tonga Ali.

01:42:13.440 | Sometimes it's called, and forgive me,

01:42:15.560 | that it's hard to pronounce, but Uricoma longifolia jack.

01:42:20.560 | They always seem to have these names

01:42:22.760 | that kind of allude to androgenic features.

01:42:27.120 | Like, I don't know why longifolia jack.

01:42:29.280 | I don't know.

01:42:30.240 | I think it's kind of obvious

01:42:31.400 | why that sounds sort of androgenic.

01:42:34.000 | This has been shown in several studies,

01:42:37.600 | and you can find these on examine.com

01:42:39.160 | or you can go to PubMed if you like.

01:42:40.420 | I've looked at these.

01:42:41.260 | That it does seem to have some pro-fertility,

01:42:43.780 | pro-free testosterone and subtle aphrodisiac effects.

01:42:48.780 | It does also seem to be a slight anti-estrogen.

01:42:52.560 | So the reports of this are people take this anywhere

01:42:56.420 | from 400 to 800 milligrams a day.

01:42:58.440 | Again, I'm not suggesting you do that,

01:42:59.880 | but that's kind of what's out there.

01:43:01.260 | And there is some decent scientific literature

01:43:03.860 | to support the fact that it liberates

01:43:05.680 | some of the bound testosterone

01:43:07.800 | and allows more free testosterone to be available.

01:43:10.540 | Some of the reported quote-unquote side effects

01:43:12.880 | are things like excessive alertness and insomnia

01:43:15.880 | if it's taken too late in the day and so forth.

01:43:17.660 | But I encourage you to explore that further

01:43:19.820 | if increasing free testosterone

01:43:22.580 | is something that you're interested in doing.

01:43:25.440 | examine.com includes a lot of other things

01:43:29.580 | that can increase testosterone.

01:43:31.920 | One of the things that's been purported

01:43:34.260 | to free up testosterone in the blood

01:43:36.920 | are things like nettles, stinging nettles.

01:43:39.820 | Although I should point out

01:43:40.880 | that the literature points to stinging nettle

01:43:42.480 | also having some fairly potent effects

01:43:45.120 | on the prostate and on the liver.

01:43:47.280 | And so it might be a tricky molecule,

01:43:49.040 | maybe not an attractive one for people to take.

01:43:52.280 | So we talked about creatine, we talked about Tonga Ali.

01:43:54.440 | It's clear that boron, which is really interesting,

01:43:57.360 | believe it or not, I think boron comes from,

01:44:00.200 | I think these were like meteors that landed on earth

01:44:02.440 | that now they extract boron.

01:44:03.880 | It's one of these crazy stories that when you look at it,

01:44:07.400 | you go, how could that possibly be?

01:44:08.680 | But there's actually, that's how it works.

01:44:11.020 | That boron, there's some scientific support

01:44:14.760 | for it freeing up more testosterone.

01:44:16.480 | And again, freeing up testosterone

01:44:17.720 | may be exactly what you want.

01:44:19.280 | I just don't think that we should demonize

01:44:21.140 | these carrier proteins like albumin and SHBG.

01:44:23.860 | In fact, albumin is very important for testosterone

01:44:26.640 | to be able to make it into the brain

01:44:28.280 | to have some of the proandrogenic effects

01:44:31.420 | on the cognitive effects of testosterone.

01:44:33.600 | Because in both males and females,

01:44:35.200 | testosterone can shift these behaviors

01:44:38.140 | like mate seeking, reductions in anxiety and so forth

01:44:43.140 | that we talked about before,

01:44:44.760 | only by making it into the brain.

01:44:46.200 | And there is this thing called the blood brain barrier,

01:44:48.460 | which is fascinating and deserving of an entire episode also.

01:44:51.840 | And getting molecules across the blood brain barrier,

01:44:54.840 | even if they're sex steroid hormones,

01:44:56.720 | which are lipophilic and can pass through cell membranes,

01:44:59.400 | requires carriers.

01:45:00.800 | And those carriers often are bound to or include albumin.

01:45:05.600 | And so it's not the goal to free up all your testosterone,

01:45:10.600 | but getting free testosterone into a range

01:45:13.140 | that works for your particular goals and needs

01:45:15.580 | is an attractive one.

01:45:17.180 | And that's why we're discussing these particular tools.

01:45:19.700 | The amounts of boron that people take,

01:45:21.660 | and you can find this again on PubMed or Examine,

01:45:24.300 | but people take a couple of grams of it a day.

01:45:26.400 | I'm not aware of any specific side effects,

01:45:28.120 | but you always, always, always want to examine

01:45:30.240 | for the particular side effects.

01:45:31.960 | And people with different backgrounds and conditions,

01:45:34.580 | as we talked about for menopause and estrogen,

01:45:37.100 | have to be careful,

01:45:38.100 | because when you're starting to modulate hormones,

01:45:40.900 | you're starting to modulate not just the tissues

01:45:44.020 | that thrive on binding of those hormones,

01:45:46.900 | but remember, the reason why there's so much breast cancer,

01:45:51.220 | and there's a reason why there's so much testicular cancer

01:45:53.340 | is that any tissue that undergoes rapid reproduction

01:45:57.220 | of particular cells,

01:45:58.240 | so there's a lot of reproduction of cells

01:46:00.660 | and shedding of uterine lining

01:46:01.900 | and the reproduction of cells and eggs in the ovary,

01:46:04.540 | and in the testes, there's the production

01:46:06.260 | of Leydig and Sertoli cells,

01:46:09.220 | and there's this kind of ongoing production of sperm.

01:46:12.660 | That's why those tissues are particularly vulnerable

01:46:15.460 | to the development of cancers,

01:46:16.640 | and many of those cancers are androgen-sensitive.

01:46:18.860 | That's why one of the major treatments

01:46:21.240 | for prostate overgrowth or prostate cancer

01:46:23.740 | is to give antiandrogenic drugs, okay?

01:46:26.740 | It's not just to shut down all things

01:46:29.780 | related to being androgenized.

01:46:33.020 | It's really about trying to prevent testosterone

01:46:35.720 | from encouraging growth of tumors.

01:46:37.660 | So I want to really emphasize the caution there,

01:46:41.540 | because it is easy when thinking about optimizing estrogen

01:46:44.900 | and testosterone to just think, oh, more is better.

01:46:47.480 | More is definitely not better,

01:46:48.940 | and it's not just because they can aromatize

01:46:50.740 | or convert into other things.

01:46:52.420 | It's because cancers or any tissue

01:46:54.920 | that has a lot of turnover of cells

01:46:57.780 | is going to thrive on androgen,

01:47:00.340 | anything that promotes growth.

01:47:01.580 | It's going to thrive on estrogen.

01:47:03.520 | Remember, brain tissue doesn't turn over that much.

01:47:05.740 | There isn't really much production of new neurons.

01:47:07.660 | Brain cancers happen, but they're kind of rare,

01:47:09.580 | and when they do happen, they tend to be glial cells,

01:47:11.900 | which have a lot of proliferation.

01:47:13.520 | Glial cells can proliferate.

01:47:14.940 | Adult neurons don't create more of themselves.

01:47:17.060 | They don't create more neurons in general,

01:47:19.420 | except in a few places in the brain and body.

01:47:21.860 | So any tissue that recycles itself is prone to cancers,

01:47:26.860 | and those tissues thrive on androgens and estrogens

01:47:31.260 | to create more tumors.

01:47:32.640 | So you have to be careful

01:47:34.060 | anytime you're modulating hormones,

01:47:35.580 | especially androgens and estrogens.

01:47:38.420 | And in my scouring of the literature

01:47:40.020 | and looking at kind of what's out there

01:47:41.820 | and what people are talking about,

01:47:43.860 | and I also mean in the scientific literature,

01:47:46.700 | one of the things that is new to me anyway,

01:47:49.860 | probably not new to a lot of the gym rats out there,

01:47:54.380 | or the people that spend a lot of time on YouTube videos

01:47:56.460 | talking about androgens are these,

01:47:59.740 | forgive me for butchering the name again,

01:48:01.540 | are these ectosteroids.

01:48:03.620 | So ectosteroids are molecules

01:48:08.360 | that come from things like spinach, believe it or not,

01:48:12.100 | that have a lot of similarity to the cholesterol molecule.

01:48:16.420 | The one that's being discussed a lot out there right now

01:48:19.220 | is something called turkisterone.

01:48:21.860 | I wish I knew why it was called turkisterone.

01:48:23.520 | Someone tell me why it's called turkisterone.

01:48:25.020 | Does it have anything to do with turkeys?

01:48:27.380 | I don't know why it's called turkisterone.

01:48:30.300 | Perhaps someone will know.

01:48:32.300 | In any case, these ectosteroids

01:48:35.020 | are similar enough to cholesterol.

01:48:36.820 | Remember cholesterol is the precursor

01:48:39.300 | to testosterone, cortisol, and estrogen.

01:48:42.060 | And it appears that some of these ectosteroids

01:48:45.800 | do have bioavailability

01:48:48.060 | or their metabolites are bioavailable.

01:48:49.980 | And this was something that for many years

01:48:52.620 | people talked about whether or not

01:48:53.980 | insect hormones or hormones from other species

01:48:56.740 | could actually be used by humans

01:48:58.940 | or whether or not it would have any effect at all.

01:49:01.320 | And it's pretty clear based on a study

01:49:03.480 | that I was able to find.

01:49:04.400 | There's a paper that came out in 2019.

01:49:06.980 | It's a comparative study in the archives of toxicology.

01:49:11.100 | This is Isenman et al., I-S-E-N-M-A-N-N et al.,

01:49:15.900 | that talks about the ectosteroids

01:49:17.820 | and was given in conjunction with strength training

01:49:21.960 | or no strength training.

01:49:22.880 | This is a 10-week intervention.

01:49:24.300 | And their conclusion is that these ectosteroids

01:49:27.540 | had a fairly significant, above placebo controls,

01:49:31.360 | increases in muscle mass, strength, hypertrophy effects,

01:49:34.940 | all the sorts of things that one would expect

01:49:37.020 | with increases in androgen.

01:49:39.540 | Their conclusion of this study is not my conclusion,

01:49:43.540 | although I may or may not agree with them.

01:49:45.300 | This isn't about my opinions.

01:49:46.540 | It's just, I want to be clear.

01:49:47.480 | These are their words, not mine.

01:49:48.940 | But they say that in their words,

01:49:52.940 | our results strongly suggest the inclusion of ectosteroid

01:49:55.460 | in the list of prohibitive substances.

01:49:56.920 | So they're saying these things are so powerful

01:49:58.580 | that they should be on the list of banned substances,

01:50:00.240 | which might be upsetting to some,

01:50:04.340 | or some of you might be thinking, well, who cares?

01:50:07.400 | The whole issue of augmenting hormones in sport

01:50:12.400 | is a very interesting issue.

01:50:14.600 | In fact, if you just want a little anecdote about that,

01:50:16.900 | I can't reveal names here, of course,

01:50:18.860 | but what I learned recently was very surprising to me,

01:50:21.860 | which is that many athletes in pro sports

01:50:24.860 | are taking testosterone,

01:50:27.020 | and they are able to do that legally,

01:50:30.540 | not just because it's available by prescription,

01:50:32.500 | but they are allowed to do that

01:50:33.860 | under the rules of their sport,

01:50:35.860 | in the fine print that no one, including me, had ever seen,

01:50:38.860 | if they've had an injury.

01:50:41.140 | So if athletes are injured,

01:50:42.800 | then it opens up the door for certain forms

01:50:45.660 | of testosterone augmentation

01:50:47.860 | and other types of augmentations

01:50:50.460 | that are not available to them if they're not injured,

01:50:52.740 | which always makes me wonder now

01:50:54.140 | when I see them getting injured,

01:50:55.180 | whether or not that's an attempt to get some of the support,

01:50:57.660 | because there's absolutely no question

01:51:00.060 | that estrogens and testosterone modulate gene expression,

01:51:03.980 | modulate strength, modulate the way the brain works,

01:51:06.380 | modulates our relationship to effort and anxiety, et cetera.

01:51:09.660 | And while we're talking about supplementation,

01:51:11.820 | the effects of supplementation, I would say,

01:51:15.100 | in some individuals can be quite dramatic,

01:51:17.100 | but they're always, always, always, except in extreme cases,

01:51:22.100 | going to be far subtler, excuse me, far more subtle,

01:51:27.220 | to use the proper English,

01:51:29.900 | far more subtle than would be, for instance,

01:51:32.080 | just injecting testosterone or injecting estrogen, et cetera.

01:51:36.780 | So I think we should just be honest and upfront about that.

01:51:40.020 | So thus far, in terms of talking about optimizing hormones

01:51:44.980 | and in the discussion of supplementation,

01:51:47.420 | I haven't really talked about things

01:51:49.800 | that actually affect the brain directly,

01:51:51.720 | that increase the pituitary output and things of that sort.

01:51:54.780 | We've mainly been talking about things

01:51:55.880 | that free up testosterone or that increase estrogen

01:51:58.700 | at the level of the periphery.

01:52:00.580 | But if you remember way back to the beginning of this episode

01:52:02.980 | hormones are made in different locations in the body,

01:52:05.120 | and there are hormones that promote the release

01:52:07.840 | and the production of hormones

01:52:09.380 | from other tissues in the body.

01:52:10.460 | And one of the main hormones for that is luteinizing hormone.

01:52:14.140 | Luteinizing hormone, again, comes from the pituitary,

01:52:16.340 | circulates, and either goes to the ovary

01:52:18.820 | to promote various aspects of egg maturation,

01:52:23.820 | as well as production of estrogen,

01:52:26.660 | and to the testes to promote

01:52:29.100 | testosterone and sperm production.

01:52:31.700 | And the prescription version

01:52:35.380 | of increasing luteinizing hormone is something called HCG,

01:52:39.100 | or human chorionic gonadotropin,

01:52:40.740 | which has been synthesized and is now available

01:52:42.900 | as a prescription drug.

01:52:44.460 | It's taken in various contexts for increasing fertility,

01:52:48.880 | both by males and by females.

01:52:51.020 | It can increase for all the reasons that now make sense.

01:52:54.680 | It can increase sperm production.

01:52:56.020 | It can produce ovulation frequency.

01:52:59.020 | It can produce the number of eggs even that are deployed

01:53:02.180 | in a given ovulation,

01:53:03.620 | although that's not always a good thing.

01:53:05.580 | It basically is pro-fertility, pro-testosterone,

01:53:10.020 | pro-estrogen, depending on your background.

01:53:12.940 | And what's interesting is HCG was initially synthesized,

01:53:17.940 | collected and synthesized from pregnant women's urine.

01:53:22.220 | And believe it or not, before it was synthetically made

01:53:27.020 | and sold as a prescription drug,

01:53:29.720 | there was actually a black market for pregnant women's urine

01:53:33.560 | where people would buy the urine.

01:53:35.260 | I don't know, I'm guessing that they probably

01:53:37.840 | just consumed it, which is weird.

01:53:40.580 | But in any case, human chorionic gonadotropin

01:53:44.200 | is now available as a prescription drug.

01:53:46.320 | And it's one of the things that many people use

01:53:48.560 | to increase testosterone or estrogen

01:53:51.160 | for increasing fertility.

01:53:52.800 | Some cases I think it's used to increase sports performance

01:53:55.740 | or when people have shut down their gonads

01:53:59.120 | for whatever reason because of excessive hormone therapies,

01:54:01.960 | or they have some sort of,

01:54:04.980 | sometimes they're actually lesions to the pituitary,

01:54:07.600 | sometimes people will have a tumor in the pituitary.

01:54:10.220 | It's actually not common, but among brain tumors

01:54:13.420 | and neural tumors, it's one of the more common ones.

01:54:15.900 | And then you get deficiencies in LH and FSH,

01:54:18.340 | and so people will take HCG to stimulate the gonads.

01:54:20.920 | So there are a variety of reasons

01:54:21.900 | why these drugs were created.

01:54:23.820 | But there are certain supplements, not many,

01:54:26.400 | that apparently can increase luteinizing hormone

01:54:28.980 | and thereby can increase testosterone and estrogen.

01:54:31.980 | And one of the more well-documented ones

01:54:34.540 | is phadogia agrestis, that's F-A-D-O-G-I-A,

01:54:39.120 | separate word A-G-R-E-S-T-I-S,

01:54:42.900 | which at least according to the literature

01:54:45.920 | that I was able to find

01:54:47.040 | can increase levels of luteinizing hormone

01:54:49.080 | and thereby levels of testosterone or levels of estrogen.

01:54:52.440 | And again, if an individual were to take phadogia agrestis,

01:54:55.920 | what they would probably find

01:54:57.000 | is that testosterone and estrogen would increase

01:54:59.960 | in anyone of any chromosomal or gonadal background.

01:55:03.320 | But remember, it's the ratio of both.

01:55:05.040 | So both, if someone has low estrogen, high testosterone,

01:55:08.420 | let's say they have testes just by way of example,

01:55:10.260 | then both of those would be expected to increase.

01:55:13.320 | And if someone has high estrogen and low testosterone,

01:55:15.820 | and let's just say has ovaries,

01:55:17.880 | then both of those would increase

01:55:19.540 | by taking phadogia agrestis.

01:55:21.960 | The side effect profile of phadogia agrestis

01:55:24.260 | hasn't really been documented, so it's a little unclear.

01:55:27.540 | I just want to emphasize

01:55:29.340 | that anytime someone's going to start taking supplements

01:55:32.340 | that, or modifying sex steroid hormones,

01:55:34.900 | getting blood work done is extremely important

01:55:38.740 | for safety reasons,

01:55:39.660 | and also just to know whether or not things are working.

01:55:42.100 | And because all of these things

01:55:43.860 | are subject to negative feedback,

01:55:45.840 | talked about this previously, previous episode,

01:55:48.700 | but if testosterone goes high or too high,

01:55:51.560 | it can feed back and shut down luteinizing hormone,

01:55:54.320 | which will then shut down further testosterone production.

01:55:57.200 | Likewise, if estrogens are going too high

01:55:59.580 | or they're going too high at various phases of the cycle,

01:56:02.160 | that can start to throw off various other hormones,

01:56:05.460 | including FSH, progesterone, LH.

01:56:09.900 | The menstrual cycle itself

01:56:11.140 | is a just absolutely exquisite balance

01:56:13.820 | of feedback of luteinizing hormone kept low and constant,

01:56:17.500 | at least for the first 14 days of the cycle.

01:56:19.800 | Then mid-cycle, there's a peak,

01:56:21.380 | and that's typically when ovulation occurs.

01:56:24.180 | That's why pregnancy is most likely

01:56:25.940 | during the middle of the 28-day cycle.

01:56:28.140 | FSH kind of goes up and then down across the first 14 days.

01:56:33.120 | So taking anything or really modifying one's estrogens

01:56:37.160 | or testosterone on that background of the menstrual cycle

01:56:40.380 | is really going to disrupt the way those things interact,

01:56:42.800 | and it's just such an exquisite feedback loop.

01:56:45.100 | So I'm not saying don't do that,

01:56:48.200 | but you definitely want to be aware of what you're doing,

01:56:50.840 | and blood draws are one way to do that.

01:56:52.840 | Monitoring cycles for ovulating females

01:56:55.780 | is another way to do that.

01:56:56.700 | And in males, having a good window

01:56:58.900 | into what's going on with testosterone,

01:57:00.620 | DHT, aromatase, estradiol, LH, et cetera, is just vital.

01:57:05.620 | And it's really part and parcel with the practice

01:57:09.740 | of thinking about optimizing these incredible things

01:57:12.340 | that we call sex steroid hormones,

01:57:13.940 | estrogen, and testosterone, and their derivatives.

01:57:16.340 | The list of supplements and molecules

01:57:18.580 | that can adjust estrogen and testosterone is vast,

01:57:22.220 | and I only touched on a few of these.

01:57:23.820 | I really tried to emphasize the ones

01:57:26.000 | for which there are human studies,

01:57:29.280 | or that have mostly human studies,

01:57:32.640 | or maybe even just one human study.

01:57:34.300 | There are other things out there

01:57:36.680 | for which there are scientific data,

01:57:38.140 | things like bulbine natalensis,

01:57:39.740 | which definitely has support for increasing testosterone,

01:57:42.940 | but all the studies were in rats.

01:57:45.180 | I think there is some evidence in humans,

01:57:46.780 | but the evidence mainly comes in the form

01:57:48.660 | of what we call sponsored research,

01:57:50.660 | so companies paying for research,

01:57:52.780 | which is different than independent research

01:57:54.860 | by people who are not biased in terms of the outcome.

01:57:58.340 | And the reason I didn't throw out things

01:58:00.060 | like bulbine natalensis is they seem to have liver toxicity

01:58:04.080 | similar to high levels of anabolic exogenous steroids.

01:58:08.220 | There's some problems associated with them

01:58:10.560 | that make them important to think about

01:58:14.720 | if you're curious about this area and the endocrinology,

01:58:18.360 | but also somewhat precarious.

01:58:21.380 | And that's one category,

01:58:23.720 | so stuff that doesn't have a lot of evidence in humans

01:58:26.080 | might actually be dangerous.

01:58:27.580 | The other category of things that has been shown to improve

01:58:32.760 | or levels of, or increase, I should say,

01:58:35.060 | I don't want to say improve 'cause it's up to you

01:58:36.980 | whether or not you want to increase

01:58:37.860 | or decrease estrogen and testosterone,

01:58:39.660 | that's highly individual, how could I know,

01:58:41.800 | are the things that are kind of housekeeping

01:58:43.760 | for production of estrogen and testosterone,

01:58:45.800 | things like magnesium, things like D3, things like zinc.

01:58:50.080 | Those are the things that are going to create

01:58:53.080 | an overall milieu of opportunity

01:58:56.200 | to produce normal endogenous levels

01:58:58.440 | rather than increasing endogenous levels further.

01:59:01.720 | And so I really want to highlight that there's a difference

01:59:04.220 | between taking something to create a kind of backdrop

01:59:07.260 | of general support and taking something

01:59:09.400 | that's going to create a big inflection

01:59:11.740 | in the levels of a given hormone.

01:59:14.040 | So once again, we covered a tremendous amount of information.

01:59:17.320 | We covered some basic science of hormones and pheromones,

01:59:20.660 | estrogen and testosterone and their derivatives.

01:59:23.340 | We talked about supplementation and behaviors,

01:59:26.400 | competition and parenting,

01:59:28.220 | and how all these things interact.

01:59:30.280 | And I hope that you'll come away from this

01:59:32.560 | with a deeper mechanistic understanding

01:59:34.600 | of how the brain and body are interacting

01:59:37.480 | to control the output and the ways

01:59:41.120 | in which these incredible things

01:59:42.720 | that we call sex steroid hormones work and influence us.

01:59:45.920 | I hope you'll also come away with some ideas

01:59:47.600 | of things that you can do in particular behavioral practices

01:59:51.140 | that can improve sleep and your relationship to light,

01:59:54.100 | et cetera, because those things really set the foundation,

01:59:57.800 | not just for healthy steroid hormone output,

02:00:01.560 | but for all sorts of health effects

02:00:04.660 | and for both the psychology and the biology

02:00:07.980 | of your nervous system.

02:00:09.940 | So I'm sure there'll be many questions.

02:00:11.980 | There are many things that I couldn't get to today.

02:00:14.660 | I do try and limit these episodes to about 90 minutes,

02:00:17.000 | which is the optimal ultradian cycle for learning.

02:00:20.800 | It's a lot of information,

02:00:21.760 | but we've timestamped everything for you.

02:00:23.360 | So feel free to look over it in parts

02:00:26.400 | or circle back where you might want deeper understanding.

02:00:29.500 | And please put your questions in the comment section below.

02:00:32.640 | Please put suggestions for future episodes

02:00:35.320 | and things that relate to hormones

02:00:36.920 | in the comment section below.

02:00:38.560 | We do look at those and we do use them

02:00:40.260 | to inform the content for subsequent episodes.

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02:01:23.040 | As well, we've partnered with Thorne, T-H-O-R-N-E,

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02:01:29.260 | The reason we partnered with Thorne

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02:02:14.140 | In closing, I hope you'll leave today's episode

02:02:16.500 | with a much richer understanding of the mechanisms

02:02:19.240 | that control the endocrine and nervous system

02:02:21.320 | in the context of estrogen and testosterone,

02:02:24.020 | as well as take away various tools

02:02:25.980 | that you might choose to apply.

02:02:28.100 | And next week, we'll be back with another episode

02:02:31.260 | about the role of hormones

02:02:32.620 | and its important interactions with the nervous system,

02:02:35.820 | and that will, of course, include both mechanisms

02:02:38.280 | and tools as well.

02:02:39.700 | And as always, thank you for your interest in science.

02:02:42.500 | [upbeat music]

02:02:45.080 | [MUSIC PLAYING]

The Science of How to Optimize Testosterone & Estrogen

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