Welcome to the Huberman Lab Podcast, where we discuss science and science-based tools for everyday life. I’m Andrew Huberman, a professor of neurobiology and ophthalmology at Stanford School of Medicine. This podcast is separate from my teaching and research roles at Stanford, but is part of my desire and effort to bring zero cost to consumer information about science and science-related tools to the general public.

In keeping with that theme, I’d like to thank the sponsors of today’s podcast. Our first sponsor is Four Sigmatic, a wellness company that makes mushroom coffee. If you’re asking why you’d want to put mushrooms in coffee, let me assure you that these are not psychedelic mushrooms, and the coffee doesn’t taste like mushrooms – it’s delicious!

I have been using Four Sigmatic coffee for several years now, long before I ever had the podcast or Four Sigmatic was a sponsor. The two kinds of mushrooms that are in Four Sigmatic coffee are lion’s mane and chaga mushrooms, both of which have been shown to have a slight anxiolytic effect to reduce anxiety. Additionally, lion’s mane has been shown in several studies to lower the symptoms of depression just slightly. Although I wouldn’t consider it a treatment for depression, the effects were real in the studies that I’ve found.

If you’d like to try Four Sigmatic, you can go to foursigmatic.com/huberman. That’s F-O-U-R-S-I-G M-A-T-I-C dot com slash Huberman. And if you do that, you’ll get 40% off your order plus free shipping on mushroom coffee bundles. That’s foursigmatic.com/huberman for up to 40% off and free shipping.

Blinkist is an app that has thousands of nonfiction books condensed down to just 15 minutes of key takeaways that you can read or listen to. I’m a big reader and consumer of nonfiction and usually consume books in their traditional form like a book where you flip the pages and so forth. Additionally, I listen to full length audio books. However, over time we know that we forget lots of things. Even though I think I got all the critical information from a book, when I listen to Blinkist and get the 15-minute rundown, either in audio or written form, I find there are key points that oftentimes I missed. It’s a great way for me to both jog my memory and to bring forward ideas that I hadn’t considered previously.

They have thousands of nonfiction titles and some really terrific ones in the science category. For example, David Eagleman’s book “Livewired” which came out recently as a book I read in full length form and I’ve listened to the Blinkist version of it as well. “Livewired” is a book about neuroplasticity.

The brain’s ability to change in response to experience is an interesting phenomenon that has generated many questions and requests for books about neuroplasticity. In my opinion, the most recent and up-to-date book on the subject is “Livewired” by David Eagleman.

David Eagleman is a professor of genetics at Harvard Medical School and his book “Lifespan” is a terrific book about aging as a disease, the future and present of longevity treatments. Additionally, Matt Walker’s book “Why We Sleep” is a great book about the science of sleeping and how to improve sleep. All of these books are available on Blinkist, which offers unlimited access to their massive library of nonfiction.

Blinkist is offering Huberman Lab Podcast listeners a special offer. Right now, you can go to blinkist.com/huberman to get a free seven day trial and 25% off when you sign up. Munk Pack is a company that makes keto-friendly snacks that taste incredible but have just one gram of sugar or less. I personally don’t follow any one particular diet, but I do fast in the early part of the day and eat low carb and keto-ish throughout the day for alertness and attention.

I can work and focus and don’t feel sluggish or brain fog. At night and in the evening, I tend to eat my carbohydrates to aid the transition to sleep. Munk Pack bars are a terrific snack, no matter if you’re keto all the time, low carb, or not. They are absolutely delicious and I don’t say that lightly. I’m usually not a fan of bars in general as they usually taste like a combination of metal bumper, cardboard, lawn trimmings, and artificial sugar. However, when Munk Pack bars were sent to me, I tried them and was pleasantly surprised. I liked them very much.

I’m a huge fan of Munk Pack. It’s a problem because I can’t keep my hands off the boxes and I keep buying more! I keep the boxes in my basement so I don’t tear through them all at once. My favorite flavor is caramel sea salt, it’s delicious and just talking about it makes me hungry for one! They also have sea salt, dark chocolate, and peanut butter dark chocolate flavors. Not only are they keto-friendly, but they are also gluten-free, plant-based, non-GMO, no soy, trans fat, sugar alcohols, or artificial colors. That means all the bad stuff that you don’t want is out of the equation! Plus, each bar has less than one gram of sugar. I’m a huge fan of Munk Pack!

If you want to try Munk Pack, you can go to munkpack.com and enter the code Huberman at checkout to get 20% off your first purchase of any Munk Pack product. This month, we’ve been talking all about hormones, which are these absolutely incredible chemicals in our brain and body. They impact our entire lifespan, from the time we are in the womb until the time we die. They are controlling the development of our brain and bodies, and development lasts the entire lifespan. Contrary to what most people think, development is a continual process from the time you’re conceived until the time you die.

Hormones play an important role in the body by constantly updating and changing the different functions. They have two major types of effects: immediate effects and gene expression. Immediate effects occur when hormones bind to cells, impacting cell growth and other processes. Gene expression is how hormones control body hair growth, breast development, muscle growth, limb growth, and height during puberty. We have discussed testosterone, estrogen, insulin, glucagon, and other hormones, and today we will be talking about metabolism, specifically thyroid hormone and growth hormone, as well as related pathways.

I’m going to explain to you the logic of how thyroid hormone and growth hormone work. It will become obvious why I’ve paired these two hormones together in the same episode. I will discuss tools that you can use to elevate or reduce thyroid hormone, as there are cases where people want to reduce it. I will also talk about tools that you can use to elevate growth hormone, although there are rare cases where people want to reduce it. Most people are interested in increasing growth hormone, and today’s episode will be rich with actionable information and organizational logic. This way, you can come away from this episode, and from the entire month on hormones, understanding at some level what these hormones are and how they work. This will arm you to encounter information from me, from books, from courses, or from other sources and make sense of how to work with these incredible chemicals.

So, in that sense, you can say that beets are good for your cardiovascular system. But that has nothing to do with the shape of the beet.

I want to acknowledge the question as a valid one, as I see it every once in a while out there. People will say, for example, that walnuts are in the shape of the brain and therefore they are good for your brain, or that a particular fruit like the beet often looks like a heart and it’s good for your heart. However, I am not aware of any science whatsoever supporting the idea that the shape of a given food or object is relevant to its functional role in the body in reference to biology.

Beets do contain a substance called arginine, which can control the dilation of blood vessels and arteries. So, in that sense, one can say that beets are good for your cardiovascular system. But this has nothing to do with the shape of the beet.

Walnuts contain various fatty acids that may be beneficial for certain aspects of brain health. However, there is no evidence that the shape of the food itself is relevant. People have gone out there and found foods that contain certain substances like carrots and vitamin A or walnuts and particular fatty acids or beets and arginine and selected the foods that happen to be in the shape of the thing that the particular substance might benefit or support. However, there are many other sources of these nutrients that don’t come from walnuts or from beets or from carrots. Therefore, the idea that the shape of some food is an indication of whether or not that food would be healthy for a particular organ in the body is unfounded. There is no evidence for it and it bears very little, if any, relevance to the nutrients that it contains and therefore the organs that it supports.

Before we move into today’s material, last episode I talked about the problems with emulsifiers in highly processed foods and the way that they can strip the mucosal lining of the gut and limit the signaling of hormones like CCK that can signal to the brain satiety, the signal to stop eating. We also discussed artificial and noncaloric sweeteners, with Stevia being a noncaloric sweetener. Several people reached out to correct me, and thanks to many of you that also sent me some references, it does not appear that Stevia can negatively impact the gut microbiome. It does seem unique among noncaloric sweeteners, and there are probably others out there. Additionally, Stevia can lead to slight increases in blood glucose, but can also improve insulin management just slightly, probably canceling to zero in terms of its impact on blood glucose, provided it’s not at concentrations that are super, super sweet.

Ingestion of anything that’s very sweet, whether or not it contains calories or not, artificial or not, will create an insulin response. In fact, just walking past a bakery and smelling delicious baked goods can increase your insulin secretion.

Thank you for the information and the references that you found. Please send additional ones if you do find them. I appreciate that you allow me to make corrections every once in a while and the opportunity to make corrections keeps us all on the same page. Please do keep any feedback that you have about particular things I cover here coming my way.

There is so much interest in metabolism. We hear about having a high or a low metabolism. There are some people out there who would like to reduce their metabolism.

Some people struggle to eat enough to maintain their weight, while others struggle to maintain a healthy weight and/or have a low metabolism. Today, we will discuss two hormones and their related pathways, thyroid hormone and growth hormone, which are most significant for setting the overall level of metabolism. Metabolism is the consumption of energy for growth of tissues, repair of tissues, and day-to-day maintenance of function. An example of maintenance of function is the brain, which uses the most energy. Most of the metabolic needs are for the brain’s thinking.

If you were to just sit in a bed all day and do nothing but think, that consumes about 75% of your metabolic needs. Now, there’s also moving around. If you have a job that requires a lot of heavy labor or lifting things or you’re a new parent and you’re carrying kids around and you’re going up and down the stairs or back and forth to the refrigerator for formula, et cetera, well then you’re burning more energy, burning more calories. But even if you are very physically active, unless you’re an ultra marathoner or a marathoner, chances are that 75% of your metabolic needs are coming just from your brain. This is because neurons consume a lot of energy; neurons are the nerve cells of your brain.

Two hormones, thyroid hormone and growth hormone, are related to metabolism of things in the body, such as keeping body fat low and keeping muscles strong and tendons strong and repairing themselves, et cetera. However, these hormones are also key for brain function, for the ability to maintain cognitive function throughout the lifespan.

The big theme to introduce is that metabolism isn’t just about losing weight, but having a high metabolism (provided it’s not too high) is great. It means that you will have more lean tissue, more bone and muscle and less adipose tissue, fat. We know that this is healthy.

Fat and muscle both play a role in metabolism, with muscle burning more energy than adipose tissue. The water in the body does not consume energy. Metabolism can be increased by adjusting the ratio of fat and muscle. Hormones, such as thyroid and growth hormones, are important for tissue repair, cognitive function, and well-being. Hormones are released from one location in the body and act on other locations. Testosterone and estrogen are also hormones that play a role in metabolism.

There are neurons in an area of the brain called the hypothalamus, located at the base of the brain in the front, above the roof of the mouth. These neurons release hormones known as releasing hormones. Examples of these include gonadotropin-releasing hormone, thyrotropin or thyroid-releasing hormone and growth hormone-releasing hormone. The releasing hormones signal another brain area, the pituitary, to release other hormones into the bloodstream. These hormones are released via axons extending from the hypothalamus to the pituitary.

The pituitary releases things, such as thyroid-releasing hormone, that have the name of stimulating hormone because they stimulate organs. In keeping with the theme of thyroid hormone, thyroid-releasing hormone is released in the brain which then tells the pituitary to release thyroid-stimulating hormone. This then travels to the thyroid and releases thyroid hormones. In the testosterone and estrogen episode, gonadotropin-releasing hormone was released in the brain, and then luteinizing hormone and follicle-stimulating hormone were released from the pituitary and traveled to the ovaries or testes. If you hear the word releasing hormone, it is coming from the brain, and the pituitary is letting go of all these hormones into the bloodstream that are stimulating different tissues. For thyroid, it is thyroid-stimulating hormone.

The thyroid is a small, butterfly-shaped gland located around the Adam’s apple. To see it, take a sip of water, look in the mirror, and swallow. The Adam’s apple is a protrusion in the trachea that is visible in everyone, regardless of gender or chromosomal background. It is more pronounced in people who had an early surge of testosterone, as it is sensitive to testosterone and affects the timbre of the voice.

The thyroid releases two hormones, T4 and T3, into the blood to stimulate different tissues and their metabolism. It also has four small bumps behind it called the parathyroid gland.

Releasing hormone comes from the brain and stimulating hormone comes from the pituitary. In this case, we are talking about the thyroid, which binds up the stimulating hormone and releases T4 and T3. T3 is the one that is more or less active, while T4 is not completely inactive, but has some roles.

Thyroid hormone has a lot of functions. Many people think that it is related to metabolism, and that those who are hyperthyroidal have bulging eyes and are thin, while those with hypothyroid are overweight and their eyes appear half closed.

Thyroid hormone (T3) has a main role of promoting metabolism. It acts on target tissues in the body, such as muscle, liver, cartilage, and bone. It is involved in using and converting energy, taking fats and breaking them down into fatty acids and converting those into ATP, and taking sugars and turning those into energy. Additionally, it can control features of the face and eyes, as well as amounts of adipose tissue.

When we eat food, it goes to adipose tissue to fat. We have different kinds of fat that we’ll talk about today, but it goes to white fat and it helps liberate some of the fats from those fat cells and use them for energy. This is why higher thyroid is associated with leaner bodies and lower thyroid is associated with less lean bodies.

One key and actionable tool for this is iodine. It comes from things in the ocean, such as sea salt, kelp, and seaweed. Most people can get enough iodine from the food they eat and/or the table salt they consume. We’ll then discuss whether or not supplementation of iodine is necessary.

Almost all table salt from all over the world contains iodine, which is essential for the thyroid to produce thyroid hormone. It is important to have sufficient levels of thyroid hormone, but not too much. However, those following a clean diet may not be getting enough iodine.
Iodine combines with an amino acid called L-tyrosine, which comes from meat, nuts, and some plant-based sources. This is the precursor to dopamine.

In the thyroid, iodine combines or works with L-tyrosine to produce T3 and T4, the thyroid hormones. Therefore, sufficient iodine and L-tyrosine are needed to produce these hormones. Additionally, selenium is also required. Goiter is a condition that is not very widespread, but it does appear in some pockets of the world such as certain areas of the United States, other countries, and Africa that are far from the ocean. People with this condition have swollen bulges in their necks because their thyroid is hypertrophying, or growing, in an attempt to churn out more thyroid hormone due to the stimulating hormone from the pituitary. The brain and the pituitary are paying attention to the levels of hormones in the blood in a cellular sense.

The hormones in our body work like a thermostat. When the levels of hormones, such as testosterone, estrogen, and thyroid, are too low, the brain will continue to push out a signal to make more. This can lead to an enlargement of the thyroid gland, known as a goiter. To prevent this, some table salt is fortified with iodine, which helps to produce thyroid hormone. However, it is important to speak with a doctor before increasing iodine intake as some people, who are hypothyroidal, might need more.

This is a serious matter. Anytime you’re talking about hormones or manipulating levels of thyroid, you absolutely want to talk to your doctor. Some people benefit from supplementing iodine, which is contained in most salts, including Himalayan salt and pink and sea salts. It can also be supplemented through things like kelp and seaweed and kelp tablets. However, if you are hyperthyroidal and make too much thyroid, this can be a problem.

The best way to figure this out is to get your blood levels tested of thyroid hormone. However, people that live near the coast can actually absorb iodine through the air by breathing ocean air, giving a sense of how little iodine you need to consume. If you are within a few miles of the ocean or visit the ocean from time to time, you are probably getting plenty. For the growth and repair of tissues, it is important to have sufficient iodine, L-tyrosine, and selenium in your diet. Metabolism is not just about body weight or body composition ratios, but also about repairing injuries, brain tissue, and clearing any damage from neurons.

Selenium is an important mineral for thyroid hormone production. Most people may not be getting enough of it to increase thyroid hormone, as the literature suggests. Selenium is necessary for the interaction between iodine and L-tyrosine, and most people do not eat foods that are high in selenium. The amount of selenium needed varies by country, with an average of 155 micrograms. People who are trying to increase thyroid levels should consume more selenium.

Consuming a vitamin with selenium is a good idea, but it’s important to make sure you’re not overdoing it by also eating a lot of selenium-rich foods. Most people could benefit from slightly more selenium than they are currently consuming, but always talk to your doctor first. Brazil nuts are the best source of selenium, with just 6-8 containing 550 micrograms. Fish, such as yellowfin tuna, is also a rich source of selenium, but there are concerns around farm-raised, mercury, etc. Personally, I avoid fish because I don’t like the taste.

Selenium is an important mineral for healthy thyroid function. For those of you who like it, you are likely skilled in knowing which fish to buy and which to avoid. Ham contains a lot of selenium, as does pork, although I am not a big consumer of pork. Beef has some selenium too. Interestingly, if you look at the sources, six to eight Brazil nuts has 550 micrograms of selenium, while other foods, such as pork, beef, turkey, chicken, cottage cheese, eggs, and brown rice, have only 30 to 50 micrograms of selenium in a much greater portion size. Therefore, if you are not eating Brazil nuts or animal-based foods, you are likely not getting enough selenium. The daily ration of selenium is typically in the 100 to 200 range, depending on your area. Other sources of selenium include mushrooms, spinach, milk, yogurt, lentils, and cashews, but even with these vegetarian options, you may not be getting enough selenium.

Selenium is an interesting thing. If you have clearance from your doctor, you could try increasing your selenium levels to see how it impacts your metabolism. Brazil nuts are the most direct way to get sufficient selenium levels, however, it is possible to overdo it. I am not aware of the consequences of getting too much selenium, but it is likely not good. For children, their daily requirements of selenium are much lower, as low as 30-40 micrograms for those 14 years or younger. In some areas, the recommended daily amount is as low as 55 micrograms. It is important to note that this is micrograms, not milligrams. To ensure healthy and productive thyroid function, it is important to make sure you are getting enough iodine, selenium, and L-tyrosine. When looking at highly processed foods, it is possible that many people are not getting enough.

Selenium has been linked to a reduced risk of preeclampsia, a rare but potentially deadly condition related to blood pressure issues during or around the delivery of a new baby. The exact mechanism is unknown, but it is worth noting for those who are pregnant or thinking of conceiving soon. Additionally, selenium has been linked to a reduced risk of prostate cancer. It is likely included in many prenatal formulas, but it is always important to consult a doctor when it comes to pregnancy or lactation.

A recent study has shown that having sufficient selenium in your diet can reduce the risk of prostate cancer. There is some evidence that consuming foods from areas with soil that is low in selenium can be a problem. On the last episode, we discussed issues related to soil quality and how it can affect hormones. However, consuming foods that are rich in selenium can offset the low content in any soil, thus reducing prostate cancer risk. This effect is minor, but statistically significant. Additionally, the study found a reduction in acne, which is likely related to the thyroid hormone pathway and its effect on the liver and various biochemical reactions. These are just some of the additional benefits of getting sufficient selenium in your diet.

People who are following very clean diets are susceptible to low iodine, as diets that are very meat rich and don’t have many vegetables, as well as diets that are very vegetable rich but don’t have many meats or salts, are at risk of lowering thyroid hormone. To simplify, those on all-meat diets may not be getting enough iodine, as they are not sprinkling or wrapping their steaks in seaweed, and may not be supplementing with iodine. People who consume vegetables should be aware that compounds within high quality cruciferous vegetables can interfere with thyroid hormone function.

Eating a variety of dark, leafy greens is important for good health, but unless those greens are kelp or seaweed, it is likely that we are not getting enough iodine. We may also be lowering the amount of thyroid we are making, as well as not getting enough L-tyrosine, which can be difficult to get in plant-rich diets. It is important to remember that our health is important, so if you are purely plant-based, make sure to get enough iodine. The same goes for those on an all-meat diet or a keto diet; if you are not ingesting many vegetables, you should make sure to get enough iodine.

I always thought that the cleaner the diet, the better. This is probably true from the standpoint of hormone regulation like estrogen and testosterone. Highly processed foods are terrible due to the phthalates, emulsifiers, and other things discussed in a previous episode. People who are not getting enough iodine need to check their levels, as consuming plants or meats can lower thyroid hormone.

Iodine can do a number of positive things related to thyroid, such as reducing something called c-reactive protein (CRP). CRP is associated with inflammation and various forms of heart and eye disease. Iodine supplementation or getting sufficient iodine from food is associated with reduced levels of c-reactive protein in the blood and an anti-inflammatory effect.

Iodine is an essential nutrient that can have a powerful effect on our health.

Interleukin 6 (IL-6) is an inflammatory cytokine that is associated with inflammation, wounds, sleep deprivation, brain injury, and infection. Iodine supplementation has been shown to reduce circulating IL-6 and thus have an anti-inflammatory effect. It is clear that iodine is an essential nutrient that can have a powerful effect on our health.

Thyroid hormone is important for a variety of reasons, such as having a high level of metabolism, maintaining a healthy body composition, brain health, cognitive function, tissue repair, and keeping c-reactive protein and IL-6 low. Eating enough iodine, selenium, and L-tyrosine is important in order to keep thyroid levels healthy. Thyroid increases glucose uptake by muscle and bone, which can increase bone mineral density and help with recovery from injuries. It does this by increasing ATP, which allows glucose to be diverted to tissues such as the brain for energy.

People are always asking me what is the food that I should eat for my brain? The fact of the matter is, what you need are nutrients that support hormones and biological pathways that support the brain. Keeping your thyroid hormone healthy at healthy levels is going to be terrific for your brain because 75% of your metabolism is from your brain. Are blueberries and walnuts good for your brain? We talked about that earlier, but the main takeaway is that supplementing or getting certain nutrients from food can actually improve or support brain function.

Having the ability of your brain to use glucose or ketones for that matter is aided by having healthy thyroid. To ensure healthy levels of thyroid hormone, take the necessary steps to eat the things that will allow for it. If you are concerned about having excessively high or low levels of thyroid hormone, look up the symptoms. Symptoms of hyperthyroidism include bulging eyes, inability to maintain weight, shaky, anxiety, thinning of hair, etc. Diagnosing hypothyroidism and hyperthyroidism is impossible through video and comments, so it is important to look up the symptoms.

Talk to your physician about the treatments available for hypo or hyperthyroid. Prescription drugs can improve symptoms related to these disorders. Synthesized thyroid is available by prescription if the body does not make enough. In cases of too much thyroid, the gland may be removed or drugs can be administered to block receptors or interfere with pathways from the brain to the pituitary or from the pituitary to the thyroid.

In addition to medical treatments, diet and supplementation can be used to maintain thyroid levels in healthy ranges. For people who menstruate, levels of thyroid hormone can fluctuate dramatically across the menstrual cycle. It may be possible to take blood at different phases of the cycle to determine if the hormone is excessively high or low.

It can be very helpful for certain people.

The endocrinologist may be willing to do this, but most people will have to figure out how supplementing certain things or getting them from foods relates to different aspects of their cycle. In general, the first half of the cycle before ovulation, people crave carbohydrates and sweets more, which makes total sense based on the biology of the menstrual cycle. Thyroid hormone is known to increase with higher intake of starchy carbohydrates. This is interesting because ketogenic diets have been shown to slightly lower thyroid levels, as blood glucose levels are very low and thyroid hormone is secreted in proportion to the amount of glucose in the bloodstream. While ketogenic diets have their place and can be helpful for certain people, it is important to understand how they affect the body.

There are now 22 studies showing that a ketogenic diet can dramatically reduce blood glucose. About a third of these studies have also shown that thyroid hormone levels are slightly reduced, and sometimes significantly, when on a ketogenic diet. This may explain why people gain weight quickly when returning to a more traditional diet after being on a ketogenic diet for a long time. Some people cycle between ketogenic and non-ketogenic diets every three or four days, while others stay ketogenic for longer periods of time. Carbohydrates, especially starchy carbohydrates, support the healthy production of T3 and T4. Therefore, if very low in carbohydrates, T3 and T4 levels will be reduced. If carbohydrates are to be brought back into the diet, it should be done gradually.

For those of you that menstruate and are craving carbohydrates in the early part of the cycle, this is actually associated with having a healthy cycle. If any of you have had a healthy cycle on a ketogenic diet, please let me know through the comments or point me in the direction of some research if you’re aware of it.

As you can start to see, there is a beautiful interplay between the different hormones, between insulin and glucose, estrogen and thyroid, and between thyroid and blood glucose and the ketogenic diet. It all starts to fit together in ways that make a lot of sense once you understand the core elements of the hormones and the variety of tissues they work on.

The simple version of this is that if you haven’t had a carbohydrate for a year, then your T3 and T4 levels are going to be pretty low. Of course, there are some ketonistas out there who might say that thyroid hormone levels go up with keto, and this might be true for other reasons, indirect reasons related to hormone pathways that are cascade from being in ketosis for long periods of time.

For most people who don’t consume any carbohydrates, their T3 and T4 levels will go down. When they start to consume foods that require thyroid metabolism, weight gain can happen more quickly. It is important to work with this carefully if one is going to be cyclic ketogenic or long-term ketogenic. For those who are not ketogenic and are consuming carbohydrates, selenium, tyrosine, and iodine are important to consider. Unless there is an underlying condition, these levels of thyroid should be in a healthy range.

Growth hormone has received a ton of attention in the last 20 years. It was a huge deal when it was first sequenced.

There was a huge patent drama involving companies, monster patents, and payouts. If you’re interested in some of the scientific history, you can look it up online. Growth hormone is a straightforward example to understand because it follows the same logic as thyroid hormone. Their functions are so closely overlapping that you may wonder why there are two systems. Growth hormone-releasing hormone comes from the brain and tells the pituitary to release growth hormone into the bloodstream. This hormone then acts on many tissues, such as muscle, ligaments, bone, and fat, to increase metabolism. Growth hormone and thyroid hormone work in parallel.

Growth hormone is important for both ends of the spectrum. In people who don’t make enough of it, it can be supplemented to help them reach a normal height. On the other hand, there are some people who make too much of it, leading to a condition called acromegaly. This is characterized by a very large stature and a bone ridge on the forehead. Both of these conditions are discussed in this episode, as they are both related to growth hormone.

Growth hormone used to be called “giantism” and most people are in the normal range of height and appendage length. This does not imply that there is a growth hormone disruption. After it was sequenced, growth hormone received a lot of attention as it meant the opportunity to inject growth hormone and replace growth hormone that was lost. There were cases of people trying to get their kids to be taller by injecting growth hormone.

Today, we will talk about things anyone can do to increase growth hormone, which can be beneficial for those who underproduce it and those who make normal levels of growth hormone, as the pituitary is churning out tons of growth hormone during puberty and development. People who overproduce growth hormone would not want to do this.

Growth hormone is responsible for the growth of the body and all its features, such as height. As we age, our production of growth hormone decreases, which is why we recover more slowly from injuries, accumulate body fat, and experience a slower metabolism. Growth hormone replacement therapy has become popular in the last 20 years, although it does come with its own set of problems. One of the major issues with injecting growth hormone is that, if levels are too high, it can cause growth of all tissues, including the heart, lungs, liver, and spleen.

Growth hormone abuse is not something we will be discussing today. Instead, we will focus on tools that anyone can use to increase their levels of growth hormone. These tools are both behavioral and supplement-based, and can be used in combination with each other. What’s great about these tools is that they are easy to implement without any special equipment or supplements. Although there are some supplements that can help increase growth hormone, the increases that can be achieved are significant. Compared to taking exogenous substances such as testosterone or estrogen, the increases in growth hormone can be up to 500% or more.

Growth hormone is released every night when you go to sleep and it is released in the early part of sleep, during so-called slow-wave sleep. In order for growth hormone to be secreted regularly for tissue repair, two conditions must be met: you must get into slow-wave sleep and your blood insulin and glucose levels must be relatively low. Eating within two hours of going to sleep will suppress growth hormone release.

Although the increase in growth hormone is short-lived, it can have powerful effects on metabolism and tissue repair. Therefore, everyone should do certain things in order to maintain healthy growth hormone levels or increase them. Before taking any action, however, it is important to speak to a doctor. Anything you add or take away is your responsibility and that of your healthcare provider.

It is very clear that some people are going to have difficulty falling asleep if they are too hungry. Therefore, it is important to decide what to eat and when to eat it so that hunger does not interfere with sleep.

The Huberman Lab Podcast, which covered sleep in episodes two, three, and four, has a plethora of tools to optimize sleep. To ensure a good night’s rest, one should not eat too close to bedtime, and should strive to reach slow-wave sleep. The first half of the night is dominated by slow-wave and deep sleep, while the second half of the night is characterized by REM sleep. What is special about the early phase of sleep is an important question that requires further research.

You should be thinking: if I listen to this podcast, I should be asking myself why slow-wave sleep allows the pituitary to release growth hormone? Delta wave activity in the brain is associated with slow-wave sleep and this triggers neurons in the brain to signal to the pituitary. Understanding this mechanism can help me increase the amount of growth hormone I release both in sleep and out of sleep.

Research has shown that sleep deprivation can lead to the release of growth hormone. This is because it is related to slow-wave deep sleep and delta waves. It is possible to measure slow-wave sleep or deep sleep using a device such as Whoop or Oura. Additionally, there are things one can do in waking to increase growth hormone release. Lastly, it is important to keep blood glucose levels low in order to increase growth hormone release.

If you need to eat close to bedtime, choose foods that won’t increase your blood glucose too much. It’s best to avoid eating too close to bedtime and try to get into a deep sleep early in the night in order to get the growth hormone release. This is because it’s the delta waves of activity in the neurons that stimulate the brain to stimulate the pituitary. Once you understand this, you can think of ways to do in waking that will allow you to release more growth hormone.

I’ve talked several times before on this podcast that I’m not a big fan of melatonin supplementation for most purposes. It may be helpful under conditions of jet lag, but it interacts with the reproductive hormones, testosterone and estrogen, in ways that are unattractive.

Melatonin is a hormone that suppresses puberty during development. It is present in much higher doses in most supplements than one would normally make; usually a hundred fold to three hundred fold. However, today I’m going to talk about an instance where very low levels of melatonin supplementation might actually be advantageous. This is aiding the transition to the delta wave, slow-wave sleep, which triggers growth hormone release. Most melatonin supplements are one milligram, three milligrams, or twelve milligrams, which is super physiological. There are some data showing that 500 micrograms of melatonin (half a milligram) can be beneficial in shifting the pattern of early night’s sleep toward more of the slow-wave deep sleep delta activity and improving growth hormone release. Although there are not a lot of studies, the ones that I saw were of quality, with both sexes and sufficient numbers. If you’re interested in melatonin supplementation, you might think about it just at very low levels.

One line of effects are what they call “altered states,” which are temporary changes in consciousness. These are the things
that most people think of when they think of meditation. However, there are also what they call “altered traits,” which are long-term, more permanent changes in the way that we think and the way that we behave.

Hundreds of micrograms as opposed to the milligram dosages are the way that some studies have shown that you can increase the amount of growth hormone that is secreted in early phases of sleep. Delta wave activity and the slow-wave activity in the brain being very important for growth hormone release and growth hormone release being so important for metabolic functions and peeling away unwanted body fat and repairing tissues, et cetera, forces us to ask, well, what other things can we do in waking in order to increase growth hormone release?

Let’s start with the ones that have a potentially big effect but are a little bit harder to access. For that, I want to point toward a book, which is really kind of interesting. It’s not focused on growth hormone but the book is called “Altered Traits: Science Reveals How Meditation Changes Your Mind, Brain, and Body.” Very interesting book. For those of you that are interested in meditation, and perhaps those of you who are not, but are considering it, what they talk about in this book is the fact that meditation has two separate lines of effects. One line of effects are what they call “altered states,” which are temporary changes in consciousness. These are the things that most people think of when they think of meditation. However, there are also what they call “altered traits,” which are long-term, more permanent changes in the way that we think and the way that we behave.

Meditation can have two types of effects on an individual: changes in state and changes in trait. Changes in state occur in the short-term, such as when a person is stressed and then practices meditation to relax. Changes in trait are more long-term, and can involve changes in personality. Certain types of meditation can simulate slow-wave sleep, which can increase growth hormone release. This is because slow-wave delta frequency activity in the brain is what controls the release of growth hormone.

Binaural beats are an attractive idea, but there is limited peer-reviewed literature to support their effectiveness. People who practice 20 minutes of meditation per day can access slow-wave sleep-like brain states. Other forms of deep rest, such as yoga nidra and hypnosis, may not necessarily put people into slow-wave sleep or delta waves. If you know of any unbiased research, please send it my way.

We’re talking about 20 minutes of more traditional type meditation. Low doses of melatonin have been used to trigger delta waves and more growth hormone release in sleep. There is science to support this. We have also discussed a waking behavior of 20 minutes of standard meditation, or simply sitting and concentrating on one’s breathing to access delta waves. Binaural beats have yet to be studied, but who knows? Maybe there is science to support it.

Finally, there are things that have been shown to have huge effects on growth hormone release in waking. These are actionable and could be implemented right away.

Exercise can have a dramatic effect on levels of growth hormone release in waking as well as in sleep. The key is the type and duration of exercise. Studies measuring growth hormone have concluded that exercise has to be of particular duration and intensity in order to get growth hormone release. Weight training and endurance training should be limited to about 60 minutes. If one exercises too long with weights or endurance exercise, cortisol levels can go high enough to inhibit the testosterone and estrogen pathways. This is why people who overexercise or exercise a lot can lose their menstrual cycles.

People who train too long and too hard can experience suppressions in testosterone. The cutoff has been 60 to 75 minutes of hard work. This will vary from person to person. To maximize the release of growth hormone, one should get warm. Studies suggest 10 minutes of warmup is sufficient. There is a review on this topic, “Growth hormone, arginine and exercise,” by Kanaley, published in Current Opinion in Clinical Nutrition and Metabolic Care.

The Current Opinion journals are generally of pretty high quality in terms of the reviews, as they tend to be quite recent. Additionally, the references therein are also quite good.
What does this mean? It means that warming up is important. Warming up does not just mean warming up the limbs and tissues that you are going to use to avoid injury, but actually warming the body. There has been some discussion about whether or not people should wear a stocking cap in cold winter months to bring the conditions and make the room warm.
Getting the body warm as a warmup seems to be important because temperature of the body seems to be an important condition or prerequisite for certain patterns of exercise to maximize growth hormone release. This is interesting to me, as I have an obsession with how body temperature, light exercise, and food interact. It appears that if you get warm, you bring up the body temperature a degree or two or maybe three, and then start exercise.

High-intensity exercise appears to be beneficial for increasing resting growth hormone levels. As discussed in a previous episode, this should not be exercise that brings muscles to failure, but rather close to it. For example, with weight-bearing exercise, one should get close to the final repetitions, but not push through them or even go to failure. This can lead to increases in growth hormone levels of anywhere from 300 to 500%. Additionally, for maximum growth hormone release in sleep, one should have relatively low blood glucose and not have eaten too close to exercise or ingested too many sugars during the exercise. Ingesting a sports drink containing caloric sugar immediately flat-lines growth hormone levels, illustrating the relationship between insulin, glucose and growth hormone.

Doing the training for anywhere from 60 to 75 minutes maximizes growth hormone release. After exercise, taking body temperature back down to normal levels quickly is associated with these big spikes in growth hormone. Otherwise, the big spikes don’t occur and the following night there is no increase in growth hormone. To ensure these spikes occur, one should warm up well, exercise for 60 to 75 minutes, and not go to absolute failure. Cooling off with a shower, ice pack, or turning off the heat in the room can help bring body temperature back down to normal levels, increasing the probability of increased growth hormone the following night. These increases can be up to 300 to 500%, almost like getting a second sleep during the day. If the exercise is too hard and body temperature stays too high for too long, the process is disrupted and the effect of increased growth hormone is not seen.

Growth hormone is powerful and its effects are mediated by the liver releasing insulin growth factor 1 (IGF-1). IGF-1 has been popular in the neuroscience community due to its ability to trigger improvements in memory and learning after exercise. Exercise triggers the release of both growth hormone and IGF-1, and IGF-1 seems to be responsible for many of the effects of improved memory. While some people report increased number of neurons or neurogenesis as the cause, it is clear that this is not the case with humans. Nonetheless, IGF-1 has positive effects on memory and cognition.

Exercise is a great way to trigger IGF-1 release and growth hormone release. The interesting thing is that certain patterns of exercise, and the duration of exercise, have different effects on IGF-1 and growth hormone depending on whether the exercise is done by men or women. This is what we call a sex-dependent effect. In one study, people exercised and their growth hormone and IGF-1 levels were measured before, during, and after exercise. It was standard resistance exercise such as squats and a sprint-like activity. The greatest increases were observed.

Exercises that involve 10 repetitions or less and six sets were performed, but none of them were to failure. It was interesting to note that women were able to access the biggest peak in growth hormone and IGF-1 early in the exercise, within the first 30 minutes. For men, the biggest increase occurred later in the exercise, at 60 minutes or so. This sex-dependent effect suggests that hormones such as cortisol, testosterone, and estrogen, which vary in different levels in men and women, will impact the release of IGF-1 and growth hormone.

Exercise can be an effective way to increase growth hormone and IGF-1 release, especially when done correctly. A recent study by Pierce et al. (2020) in Frontiers in Endocrinology found that the molecular weight isoform response to resistance exercise is sex-dependent. For women, the maximum benefit in terms of growth hormone and IGF-1 release is within the first 30 minutes of exercise. For men, however, the exercise must last for the entire 60 minutes to get the increase in growth hormone the following night. It is important to warm up, do the type of exercise discussed, and not make the exercise last so long that the growth hormone and IGF-1 release is not maximized.

My experience thus far in doing this podcast is that people fall into one of two categories: those who are eager to try supplements and maybe even prescription compounds, and those who are more focused on what they can do with diet and behaviors. I don’t have a bias either way; I try and offer tools that are supported by the scientific literature and always point to safety margins. There are supplements that can increase growth hormone to a considerable degree, although these aren’t growth hormone itself. We will also discuss prescription drugs at the end, not just growth hormone, but some other popular drugs in the entertainment industry.

There are some pretty interesting compounds that can increase growth hormone levels substantially. Arginine and ornithine, two amino acids, are known to have this effect. You can get arginine from food or supplements, and it is available in pill or capsule form, or even intravenously. The amount of arginine required to get a big growth hormone release increase is quite substantial. Therefore, some people take it before bedtime or before exercise, but only when blood glucose levels are low.

High blood glucose can quash the effect of taking arginine. The amount of arginine taken by people usually ranges from three to ten grams, although it is not recommended to take more than nine grams. Taking nine grams of arginine orally is a lot of pills and can cause gastrointestinal (GI) disturbances such as nausea, vomiting, constipation, diarrhea, and stomachaches.

Taking arginine can dramatically increase growth hormone release and the levels of increase were anywhere from 100 to 600% above baseline. It is available in a number of different supplements, including arginine and ornithine, to increase growth hormone. Arginine has the effect of dilating arterials and increasing blood supply, as it is involved in the vasodilation pathway. I have never tried arginine, however, most studies looking at its role on growth hormone levels have done so by intravenous infusion.

Arginine is a pathway that is downstream of a lot of drugs used to treat erectile dysfunction and any issues with peripheral blood flow. It works by either disrupting enzymes or adjusting the levels of amino acids to increase vasodilation. Arginine is also used to increase growth hormone release, but it can short circuit the effects of exercise on growth hormone. Studies have shown that taking arginine and exercising will only increase growth hormone levels by 300 to 500%, not 800%. This is important to note because of arginine’s effects on vasodilation.

If you have a heart condition, you should take any advice seriously. Additionally, you can supplement with arginine, but exercise and taking arginine before sleep will not have a synergistic effect on growth hormone, and the two will cancel each other out. If your goal is to increase arginine in the blood, arginine may not be the best way to do that. L-citrulline has powerful effects on vasodilation and growth hormone levels, and can lead to bigger arginine increases than taking arginine itself.

L-Citrulline is a supplement that can lead to increased blood flow, which can be used for a variety of purposes such as gym pumps. It can also lead to increased arginine and growth hormone levels. However, it should be noted that it can also lower blood pressure. Furthermore, L-citrulline may be a better way to increase arginine than arginine itself. Ornithine can also increase growth hormone, although it is not as popular as it was in the 90s.

Nowadays, people who are in the know tend to focus on L-citrulline. If you are interested in L-citrulline or arginine, I highly recommend going to examine.com. It is totally free and you can search for information. It will tell you that blood pressure will be slightly decreased, power output in the gym will increase, there are strong effects on blood glucose, fatigue is reduced notably, big increases in nitric oxide, which is related to the increase in vasodilation, and plasma arginine has notable effects which allow people more training volume and aerobic exercise. Additionally, arterial stiffness is brought down.

There is a huge list of things that have been studied and shown to have an effect. Two studies have been done in a double-blind, placebo-controlled manner, although only in males. These studies have revealed a small but significant increase in growth hormone. Additionally, other interesting effects have been seen, such as decreased c-reactive protein and increased muscle oxygenation. These effects are similar to those seen with other compounds.

The takeaway here is if you want to increase growth hormone, think about the arginine pathway, but arginine itself might not be the best direct route to get there. L-citrulline might be a better option. But please do consider take very seriously the effects on blood pressure.

We’ve been talking about big effects from supplementation or exercise on growth hormone, this extremely powerful hormone. It’s important to understand how the profile of growth hormone changes as we age. Between the ages of 30 and 40, the amount of growth hormone released each night is reduced by two to threefold.

We hear so much nowadays about how testosterone levels are dropping, sperm levels are dropping, et cetera. But if you look at the data on testosterone, there are men in their 90s who are making as much testosterone and DHT (dihydrotestosterone) as they were in their 20s. So it’s important to note that these changes are not inevitable.

I don’t dispute that testosterone levels vary tremendously from person to person. In fact, I discussed this in a recent episode. Additionally, getting older does not necessarily mean that testosterone levels are dropping. It appears that growth hormone levels decrease substantially in people in their 30s and 40s and this is the case across the board. People in their 40s, 50s, and 60s generally do not produce as much growth hormone as they did in their teens and 20s.

Personally, I noticed a difference in my 40s. Despite sleeping the same amount, I didn’t feel as able to recover from exercise or wound healing. This prompted me to look into growth hormone and optimize a great number of things.

Since the ways to manipulate growth hormone in men and women are straightforward, everybody goes through an age-related decline very dramatically. Therefore, we should be pursuing activities such as exercising, not eating too close to bedtime, and optimizing sleep. This can offset the two to threefold decrease in growth hormone for people in their 30s and 40s. Exercise and supplementation can increase growth hormone levels by 300 to 500%, which can offset the age-related decline completely. Finally, I’d like to discuss a way that anyone can increase their levels of growth hormone dramatically.

The release of growth hormone starts in the brain, in the hypothalamus. This area of the brain is responsible for controlling sexual behavior, temperature regulation, circadian behavior, aggression, and other functions. The hypothalamus then releases the growth hormone-releasing hormone, which communicates with the pituitary and causes it to release growth hormone. This growth hormone then acts on different tissues, such as muscle, liver, cartilage, and body fat, causing them to use energy and leading to an overall decrease in body fat. Growth hormone also causes an increase in muscle mass, strengthens bones, and has other effects.

Temperature has a profound effect on growth hormone levels and release. This is supported by data from animal and human studies, which have explored how making animals cold or hot can increase growth hormone. It is thought that making animals or people warmer is the way to increase growth hormone. However, it is important to note that increasing temperature is risky, as it doesn’t take much of a temperature increase in the brain to cook the neurons, which can lead to death from hyperthermia. Therefore, it is important to exercise caution when engaging in any behaviors that may increase temperature.

We have a much greater range in terms of cold than we do for warming up the brain. You can die of hypothermia or freeze to death. However, there is strong evidence that sauna, or deliberate hyperthermia, can increase the release of growth hormone and other hormones. The effects reported are quite dramatic. Even if you don’t own a sauna, there are still things you can do to increase your body temperature. For example, our study showed that warming up a few degrees before exercise led to bigger and quicker increases in growth hormone during the exercise. This indicates that temperature is important.

Entering saunas between 176 degrees Fahrenheit (80 degrees Celsius) and up to 210-215 degrees Fahrenheit can be dangerous and should be cleared with a doctor. When exposed to high heat, stroke volume of the heart increases, similar to an exercise, and the amount of blood that the heart can pump each time gets larger. The blood vessels also dilate.

There are a lot of things that happen when we enter environments with high temperatures. Sweating, dilation of blood vessels, and an increase in arginine are a few of the common themes. I want to be clear that I’m not talking about getting the body up to 100 degrees Celsius, which would be terrible and result in death. However, entering environments with temperatures ranging from 80 degrees Celsius to 100 degrees Celsius, or 175 to 210 degrees Fahrenheit, for short periods of time (20-30 minutes) has been shown to increase growth hormone release by 16 fold.

The endocrine effects of repeated sauna use were studied in 17 humans. Subjects had to do this three days in a row, each session consisting of 20 minutes in the sauna followed by a 30-minute cooling period. The results showed a 1,600% increase in growth hormone release. Additionally, effects on other hormones, such as prolactin and cortisol, were observed. It is important to note that long periods of time at high heat should be avoided, as it can cook your brain and other tissues.

Carefully structured exercise in a sauna or hot environment can lead to increases in growth hormone levels. A study conducted a few years ago found that a routine of 20 minutes in the sauna, followed by 30 minutes of cooling, followed by another 20 minutes in the sauna, led to a five-fold increase in growth hormone levels. After three days of this routine, the increase was up to 16-fold. Since then, a number of other studies have backed up the findings that deliberate hyperthermia can be beneficial, though caution must be taken to avoid going too hot. If a sauna is not available, wrestlers often use bodysuits made of plastic, which are widely available online.

People who wrap themselves in garbage bags and throw on sweats and a hoodie to go jogging must be careful, especially on hot days, as overheating can lead to death. You don’t actually need a sauna to get warm; some people will use hotel rooms while traveling. They’ll turn on the heat, make a hot bath, and fill the room with steam and heat. They’ll put on a hoodie and some sweatshirt, sweat pants, and wool socks, and sit there to get warm for 20 minutes. Afterward, they’ll take a cool shower and repeat the process. Some people own saunas, but when the hotel is paying the water bill, people don’t worry about it too much.

There are a lot of ways to increase growth hormone levels. I have friends who were in the military who made saunas out of cars while they were overseas. However, it is important to be careful and not hurt yourself. The increases in growth hormone are likely due to increased activity of neurons within the hypothalamus. These neurons stimulate growth hormone release from the pituitary, and they are closely intermixed with the neurons that regulate heat and body temperature. Metabolism produces heat, so this could be a factor in the increased growth hormone levels.

Sauna can be a very interesting tool for increasing energy consumption and usage. It has extreme effects in terms of increasing growth hormone levels. A recent study by Podstawski et al. (2021) found that sauna leads to a significant decrease in cortisol, a stress hormone, but did not change testosterone, DHEA or prolactin levels. It is recommended to proceed with caution when using sauna and to limit sessions to 20-30 minutes.

Heat seems to have positive effects on growth hormone, reducing cortisol levels, and no direct effects on other hormones like testosterone, DHEA, or prolactin. During or immediately after a sauna bath, there were no effects. We have discussed diet, supplementation, behavioral tools, and the underlying biology and logic. Safety precautions are important for all of these. Lastly, for those taking growth hormone as prescribed by a doctor, the effects should be monitored.

People taking growth hormone even though it has not been prescribed by a doctor is none of my business, but the point here is that most all of the hormones that we make have been synthesized and are available in little bottles or ampules that people can inject. If you are thinking of going this route, there are a couple of important things to consider. First, talk to a physician as these hormones are only legally available through a physician. Second, anytime you inject something, you will shut down your own production. For example, if you take thyroid hormone, you will not make thyroid hormone in the long run, and if you take testosterone, you will shut down your own production of testosterone.

Taking estrogen and growth hormone can be a temporary decision, as one can wait out the period in which they are not making testosterone, estrogen or growth hormone, and it may come back. There is a new area of study developing called peptides, which are a huge category of biological compounds. It is worth discussing, although not necessarily encouraging, as it is happening.

Peptides are strings of amino acids that can be short or long. These are known as polypeptides. When put together in different sequences, they can resemble hormones and produce similar effects when injected. For example, growth hormone-releasing hormone is produced from the brain, which stimulates growth hormone from the pituitary.

Yes, they do work.

People now will take things like Sermorelin (S-E-R-M-O-R-E-L-I-N), which is not the entire peptide sequence of growth hormone-releasing hormone, but it’s a subset of those. When people inject it before they go to sleep at night on an empty stomach, it stimulates the release of growth hormone from the pituitary. This is not taking growth hormone, but rather taking the stimulating hormone, often called a secretagogue or a mimic, which causes a secretion of the hormone that one wants. Some people are doing this by prescription with a real medical need, while others are doing it for longevity reasons, which falls into a gray zone – they wouldn’t die without it, but they want to enhance their life. Sermorelin is prescription and it does work.


Growth hormone-releasing hormone (GHRH) can be shut down by certain peptides. These peptides can change gene expression and set pathways in motion for continued production of a hormone even when the peptide is no longer being taken. This can be beneficial or detrimental, as big increases in growth hormone that are short-lived, such as those caused by exercise or sauna, can have huge effects. However, when one is injecting GHRH at a constant level, gene expression programs can be long-lived. This can be detrimental if the body has an unhealthy tumor, as tumors will grow when they see growth hormone.

People are using growth factors and peptides to increase tissue growth and recovery time. They are commonly used in the movie industry and by athletes, such as those competing in the upcoming Olympics. These peptides and compounds are separate from hormone augmentation, such as injecting growth hormones or testosterone. People are now working further up the pathways to increase the rate of tissue and wound healing. I am not making any judgement on whether or not people should do these things.

They can help us to maintain our body composition.

Peptides such as ipamorelin and tesamorelin are compounds that have been made for people in the longevity or self-augmentation field. They are not being promoted for use, however, it is important to understand their underlying biology if you hear about them or someone is talking to you about them.

Thyroid hormone and growth hormone affect our metabolism by dictating how many nutrients we can eat and make use of, as well as pull from body fat stores, repair muscle, and repair cartilage. They also help us maintain our body composition.

We have now covered an enormous amount of material about thyroid hormone and growth hormone, and hopefully now you have a better understanding of their mechanism.

They really are incredible compounds, and they’re actionable. Things like getting that early phase of sleep, supplementing with arginine (maybe not), getting adequate exercise, warming up properly, and not making the exercise too long or too intense can help. Other things like deliberate, safe hyperthermia (with the emphasis on safe) might be of use.

This brings to a close our month on hormones. Hopefully, you now understand not just thyroid and growth hormone, but the logic that underlies thyroid hormone, growth hormone, estrogen, testosterone, why we eat, why we stop eating, cholecystokinin, ghrelin. If these names don’t mean anything to you, then perhaps go back and listen to those episodes.

Regardless, I hope that you come away from this with a deeper understanding about these hormones, which are so powerful in controlling the way our brain functions and the interplay between the brain and hormones. It is really a bidirectional conversation; the brain is telling the body what hormones to make, and the hormones are influencing all the tissues of the body, but also telling the brain whether or not to eat more or grow more or think more, et cetera.

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