How to Control Your Metabolism by Thyroid & Growth Hormone

Introduction

In this section, Andrew Huberman introduces himself and the podcast. He also thanks the sponsors of the podcast.

Introduction to the Podcast

• Andrew Huberman is a professor of neurobiology and ophthalmology at Stanford School of Medicine.

• The podcast is separate from his teaching and research roles at Stanford.

• The podcast aims to bring zero cost to consumer information about science and science-related tools to the general public.

Sponsors

• Four Sigmatic: A wellness company that makes mushroom coffee. It contains lion's mane and chaga mushrooms, which have been shown to reduce anxiety, lower symptoms of depression slightly, and offset cognitive decline.

• You can go to foursigmatic.com/huberman for up to 40% off and free shipping on mushroom coffee bundles.

• Blinkist: An app that has thousands of nonfiction books condensed down to just 15 minutes of key takeaways that you can read or listen to.

• You can try Blinkist free for seven days by going to blinkist.com/huberman.

• Munk Pack: A company that makes keto-friendly snacks with just one gram of sugar or less.

• No bullet points with timestamps available.

Science Books on Blinkist

In this section, Andrew Huberman talks about some science books available on Blinkist.

Neuroplasticity Book

• David Eagleman's book "Livewired" is a book about neuroplasticity.

• It came out recently as a book he read in full length form

• It is the most recent and up-to-date book about neuroplasticity.

Aging Book

• David Sinclair's book "Lifespan" is a terrific book about aging as a disease and the future and present of longevity treatments.

• No bullet points with timestamps available.

Sleep Book

• Matt Walker's book, "Why We Sleep," is a terrific book about why we sleep, the science of sleeping, and things you can do to improve your sleep.

• No bullet points with timestamps available.

Munk Pack Bars

In this section, the speaker talks about Munk Pack bars and their delicious taste. He also mentions that they are keto-friendly, gluten-free, plant-based, non-GMO, no soy, trans fat, sugar alcohols or artificial colors.

Features of Munk Pack Bars

• The bars are delicious and come in different flavors such as caramel sea salt, sea salt dark chocolate and peanut butter dark chocolate.

• They are keto-friendly with less than one gram of sugar.

• They are gluten-free, plant-based, non-GMO and have no soy or trans fat.

• To get 20% off your first purchase of any Munk Pack product go to munkpack.com and enter the code Huberman at checkout.

Hormones

In this section the speaker talks about hormones and how they impact our entire lifespan. He explains that hormones control the development of our brain and bodies from conception until death.

Effects of Hormones

• Hormones have two major kinds of effects: immediate effects where they bind to cells impacting growth; and long-term effects where they control gene expression during puberty controlling body hair growth, breast development etc.

Thyroid Hormone & Growth Hormone

In this section the speaker talks about metabolism. He explains how thyroid hormone and growth hormone work together to control metabolism.

Thyroid & Growth Hormone

• The speaker pairs thyroid hormone with growth hormone because they work together to control metabolism.

• Tools to elevate or reduce thyroid hormone will be discussed along with tools to elevate growth hormone.

• The goal is to provide an organizational logic so that listeners can understand hormones and how they work.

Foods for Organs

In this section the speaker answers a question about whether certain foods are good for certain organs of the body based on their shape.

Foods for Organs

• The speaker acknowledges the question as valid but explains that there is no scientific evidence to support it.

• He gives examples such as walnuts being in the shape of a brain and beets looking like a heart, but says that these are just coincidences.

Beets, Walnuts, and Food Shapes

This section discusses the relationship between certain foods and their nutrients to specific organs in the body.

Beets and Arginine

• Beets contain arginine which can control the dilation of blood vessels and arteries.

• Arginine has some relationship to heart health.

Walnuts and Brain Health

• Walnuts contain various fatty acids that may be beneficial for certain aspects of brain health.

• The shape of the food itself is not relevant to its benefits.

• People have selected foods that happen to be in the shape of a particular organ that a substance like vitamin A or fatty acids might benefit or support.

• There are many other sources of these nutrients that don't come from walnuts.

Food Shapes and Organ Health

• 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.

Corrections on Stevia as a Noncaloric Sweetener

This section corrects previous information given about Stevia as an artificial sweetener.

Stevia as a Noncaloric Sweetener

• Stevia is not an artificial sweetener but rather a noncaloric sweetener.

• Ingestion of anything very sweet will create an insulin response, whether it contains calories or not.

Metabolism: Thyroid Hormone and Growth Hormone Pathways

This section discusses metabolism, thyroid hormone, growth hormone pathways, and how they affect overall metabolism.

Metabolism Basics

• Metabolism is the consumption of energy in cells for growth and repair of tissues.

• Some people want to reduce their metabolism while others struggle with maintaining a healthy weight.

Thyroid Hormone Pathway

• The thyroid hormone pathway is significant for setting overall metabolism.

• Low levels of thyroid hormone can lead to a low metabolism.

• The hypothalamus and pituitary gland regulate the production of thyroid hormone.

Growth Hormone Pathway

• The growth hormone pathway is also significant for setting overall metabolism.

• Low levels of growth hormone can lead to a low metabolism.

• The hypothalamus and pituitary gland regulate the production of growth hormone.

Introduction to Metabolism and Hormones

In this section, the speaker introduces the concept of metabolism and how it relates to brain function. The importance of two hormones, thyroid hormone and growth hormone, is also discussed.

Metabolic Needs of the Brain

• The brain consumes about 75% of metabolic needs when thinking or at rest.

• Physical activity increases energy expenditure but does not significantly affect the proportion of energy used by the brain.

• Neurons consume a lot of energy, making them a major contributor to metabolic needs.

Importance of Thyroid Hormone and Growth Hormone

• Thyroid hormone and growth hormone are important for maintaining cognitive function throughout life.

• These hormones are also involved in tissue repair after injury and can help offset dementia.

Benefits of High Metabolism

• A high metabolism can lead to more lean tissue (muscle and bone) and less adipose tissue (fat), which is generally considered healthy.

• Increasing muscle mass can increase metabolism as muscle burns more energy than fat.

Repeating Logic: How Hormones Work in the Body

This section explains how hormones work in the body, specifically focusing on releasing hormones from neurons in the hypothalamus that signal the pituitary gland to release stimulating hormones into the bloodstream.

Releasing Hormones from Neurons in Hypothalamus

• Neurons in the hypothalamus release releasing hormones that signal other areas of the brain to release specific hormones.

• Releasing hormones come from neurons in the brain and are actionable in certain ways.

• Thyrotropin-releasing hormone and growth hormone-releasing hormone are two examples of releasing hormones.

Pituitary Gland Releases Stimulating Hormones

• The pituitary gland releases stimulating hormones that act on specific organs or tissues.

• Thyroid-stimulating hormone is released by the pituitary gland in response to thyrotropin-releasing hormone from the hypothalamus, which then stimulates the thyroid gland to release thyroid hormones.

• Luteinizing hormone and follicle-stimulating hormone are examples of stimulating hormones that act on the ovaries or testes.

Understanding the Thyroid Gland

In this section, we will learn about the thyroid gland and its role in controlling metabolism.

The Thyroid Gland

• The thyroid gland is located in the neck and controls the timbre of voice.

• It releases two hormones, T4 and T3, which stimulate different tissues and their metabolism.

• Releasing hormone comes from the brain while stimulating hormone comes from the pituitary.

• T3 promotes metabolism by utilizing energy including building up tissues. It acts on muscle, liver, cartilage, bone and adipose tissue.

Iodine and Thyroid Hormone Production

• Iodine is essential for producing thyroid hormone. Most people can get enough iodine from food or table salt they consume.

• Iodine combines with L-Tyrosine to produce T3 and T4.

• Selenium is also needed for proper thyroid function.

Conclusion

In this section, we will conclude our discussion on understanding the thyroid gland.

Key Takeaways

• The thyroid gland plays a crucial role in controlling metabolism through releasing hormones that stimulate different tissues.

• Iodine is essential for producing thyroid hormone along with L-Tyrosine and selenium.

• Most people can get enough iodine from food or table salt they consume. However, those following a particularly clean diet may not be getting enough iodine.

Thyroid Hormone and Iodine

In this section, the speaker discusses how thyroid hormone is regulated by iodine and stimulating hormones from the brain. They also discuss the importance of iodine and selenium in the diet for proper thyroid function.

Regulation of Thyroid Hormone

• The pituitary gland releases stimulating hormones to regulate thyroid hormone production.

• When hormone levels are too high, the signal to make more is shut off. When levels are too low, the brain continues to push out signals to make more.

• If there's not enough iodine or thyroid hormone circulating, the gland gets bigger and people get goiter.

• Table salt has iodine in it, but other foods like kelp and seaweed can also supplement iodine intake.

Importance of Iodine and Selenium

• It's important to talk to a doctor before supplementing with iodine or manipulating thyroid levels.

• L-Tyrosine is needed for proper thyroid function along with sufficient iodine and selenium in the diet.

• Selenium allows L-Tyrosine and iodine to interact properly for thyroid hormone production.

• Most people don't eat enough foods high in selenium, which varies country by country. People trying to increase thyroid levels might want to consume more selenium.

Importance of Selenium for Thyroid Function

In this section, the speaker discusses the importance of selenium for thyroid function and how it can impact metabolism.

Sources of Selenium

• Brazil nuts contain 550 micrograms of selenium in just six to eight nuts.

• Ham and pork contain a lot of selenium.

• Other animal-based foods like beef, turkey, chicken, cottage cheese, eggs have lower levels of selenium compared to Brazil nuts.

• Vegetarian sources like mushrooms, spinach, milk, yogurt, lentils and cashews also have low levels of selenium.

Importance of Selenium

• Not consuming enough selenium can lead to an insufficient amount for healthy levels of thyroid.

• Children require much lower daily requirements than adults.

• Recommended daily intake varies by area but is not high.

• Adequate intake is important for keeping thyroid function healthy and productive.

Positive Effects on Health

• Selenium has been shown to reduce the risk of preeclampsia during pregnancy.

The Importance of Selenium

This section discusses the importance of selenium in reducing prostate cancer risk and acne.

Benefits of Selenium

• Consuming foods from areas with low selenium soil can be problematic.

• Sufficient selenium intake can reduce prostate cancer risk and acne.

• Acne reduction is likely due to the impact of thyroid hormone on the liver.

Tools for Ensuring Adequate Iodine Intake

This section discusses tools for ensuring adequate iodine intake, including the risks associated with diets that are very meat-rich or vegetable-rich.

Risks Associated with Meat-Rich Diets

• People following all-meat diets may not be consuming enough iodine.

• Iodine requirements increase if people are not consuming vegetables.

Risks Associated with Vegetable-Rich Diets

• High-quality cruciferous vegetables can interfere with thyroid hormone function.

• Unless dark, leafy green vegetables are kelp or seaweed, they do not provide enough iodine.

• Plant-rich diets make it hard to get enough L-Tyrosine.

Clean Diets and Iodine Intake

This section discusses how clean diets affect iodine intake and thyroid hormone production.

Susceptibility to Low Iodine

• People who consume no processed foods may still be susceptible to low iodine levels.

• All-meat diets without seaweed or supplemental iodine may lead to low iodine levels.

• Plant-based diets rich in cruciferous vegetables may also lower thyroid hormone production by way of the iodine pathway.

Importance of Checking Iodine Levels

• People who are not getting enough iodine need to check whether their levels need to be increased because they consume many plants or meats that lower thyroid hormone.

The Importance of Iodine, Selenium, and L-Tyrosine for Thyroid Health

This section discusses the importance of iodine, selenium, and L-tyrosine for thyroid health. It explains how these nutrients can help reduce inflammation and improve brain function.

Iodine Supplementation Reduces C-Reactive Protein

• C-reactive protein (CRP) is associated with inflammation and various forms of heart disease and even eye disease.

• Iodine supplementation or getting sufficient iodine from food is associated with reduced levels of CRP in the blood and an anti-inflammatory effect.

• Iodine supplementation can reduce circulating interleukin 6 (IL-6) associated with inflammation.

Importance of Thyroid Hormone for Metabolism and Brain Health

• Keeping c-reactive protein low, keeping IL-6 low, make sure you're getting enough iodine, selenium and L-tyrosine.

• Thyroid increases glucose uptake by various tissues, in particular muscle and bone. It actually can increase bone mineral density.

• Healthy thyroid pathways allow energy to be diverted toward bone repair and muscle repair and cartilage repair.

• Nutrients that support hormones and biological pathways that support the brain are important for brain function.

How to Support Healthy Levels of Thyroid Hormone

• Take things that are going to allow you to have healthy levels of thyroid hormone such as iodine, selenium, L-tyrosine.

• Symptoms of having excessively high or excessively low levels of thyroid hormone include bulging eyes, inability to maintain weight, shaky anxiety or thinning hair.

• If you're concerned about having excessively high or excessively low levels

of thyroid hormone look up what the symptoms are. Talk to your physician. And there are a number of good treatments.

Thyroid Hormone Regulation

This section discusses the big guns in treating thyroid disorders and how to maintain healthy thyroid levels through diet and supplementation. It also highlights the fluctuation of thyroid hormone levels across the menstrual cycle.

Treating Thyroid Disorders

• Medications can block receptors or interfere with pathways from the brain to the pituitary or from the pituitary to the thyroid.

• These are considered big guns in treating different thyroid disorders.

Maintaining Healthy Thyroid Levels

• Diet and supplementation can help maintain healthy thyroid levels.

• Carbohydrates, especially starchy ones, support healthy production of T3 and T4.

• Ketogenic diets have been shown to slightly lower thyroid levels due to low blood glucose levels.

• Gradual reintroduction of carbohydrates is recommended for those on a ketogenic diet.

Fluctuation of Thyroid Hormone Levels Across Menstrual Cycle

• Menstruating individuals may experience dramatic fluctuations in thyroid hormone levels across their menstrual cycle.

• Experimentation may be necessary to determine how diet and supplementation relate to different phases of the cycle.

Interplay Between Hormones

This section explores the interplay between insulin, glucose, estrogen, and thyroid hormones. It also discusses how long-term ketogenic diets can affect T3 and T4 levels.

Interplay Between Hormones

• There is a beautiful interplay between insulin, glucose, estrogen, and thyroid hormones.

• Carbohydrates support healthy production of T3 and T4 while low-carbohydrate diets can lead to a reduction in these hormones.

Long-Term Ketogenic Diets

• Long-term ketogenic diets can lead to low T3 and T4 levels due to lack of carbohydrate consumption.

• Weight gain may occur more quickly when carbohydrates are reintroduced after a long period of ketogenic dieting.

• Cyclical ketogenic diets may be a better option for some individuals.

Growth Hormone Overview

This section provides an overview of growth hormone, its history, and how it works in the body.

Growth Hormone Basics

• Growth hormone has received a lot of attention in the last 20 years.

• Growth hormone follows the same logic as thyroid hormone and their functions overlap closely.

• Growth hormone-releasing hormone comes from the brain and tells the pituitary to release growth hormone.

• Growth hormone increases metabolism, repair, and growth of tissues.

Extreme Cases

• Certain people who don't make enough growth hormone end up very short in stature while others who make too much end up very large with acromegaly.

• Injecting growth hormone can replace lost hormones but if levels are too high it can cause growth of all tissues including heart, lungs, liver, and spleen.

Increasing Growth Hormone Levels

This section discusses ways to increase levels of growth hormones through behavioral changes or supplements.

Reasons for Increasing GH Levels

• People who underproduce GH would want to increase levels while those who overproduce it would not.

• As we age we make less GH which leads to slower recovery from injuries, accumulation of body fat, and slower metabolism.

Tools for Increasing GH Levels

• Behavioral changes such as getting more sleep or doing high-intensity exercise can increase GH levels.

• Supplements like amino acids or melatonin can also help increase GH levels.

• Increases in GH levels can be substantial and the tools to increase them are actionable.

Maintaining Healthy Growth Hormone Levels

In this section, Dr. Huberman discusses the importance of maintaining healthy growth hormone levels and how to achieve this through sleep and diet.

Sleep and Growth Hormone Release

• Talk to a doctor before making any changes to your treatment plan.

• Growth hormone is released during slow-wave sleep in the early part of the night.

• Eating within two hours of going to sleep can suppress growth hormone release, but being too hungry can also make it difficult to fall asleep.

• Slow-wave sleep triggers the neurons in the brain that signal for growth hormone release.

Delta Waves and Growth Hormone Release

• Delta wave activity in the brain correlates with slow-wave sleep and triggers growth hormone-releasing hormone neurons to signal to the pituitary gland.

• Growth hormone is not just released on a circadian-dependent schedule; it is always related to slow-wave deep sleep and delta waves.

• There are ways to increase growth hormone release during waking hours by getting the brain into delta waves.

Tips for Maintaining Healthy Growth Hormone Levels

• Try not to eat too close to bedtime or eat anything that would increase blood glucose too much.

• Get into deep sleep early in the night for optimal growth hormone release.

Melatonin Supplementation and Growth Hormone Release

In this section, the speaker discusses the use of melatonin supplementation for aiding the transition to slow-wave sleep and improving growth hormone release. The speaker also talks about how meditation can help increase growth hormone release.

Melatonin Supplementation

• The speaker is not a big fan of melatonin supplementation for most purposes.

• Melatonin interacts with reproductive hormones in ways that are unattractive, suppresses puberty during development, and is present in much higher doses in most supplements.

• However, very low levels of melatonin supplementation (500 micrograms or half a milligram) might be advantageous in aiding the transition to slow-wave sleep and improving growth hormone release.

Meditation

• Certain types of meditation can get people's brains into states that closely mimic slow-wave sleep.

• A meditation practice that allows you to get into these slow-wave delta type frequency activity in the brain may be very beneficial because it gates growth hormone release.

• Binaural beats are an attractive idea but there are no quality peer review studies supporting their effectiveness in getting the brain into delta waves.

Exercise and Growth Hormone Release

In this section, the speaker discusses how exercise can help increase growth hormone release.

Resistance Training

• Resistance training has been shown to increase growth hormone levels immediately after exercise.

• The effect of resistance training on long-term growth hormone levels is less clear.

High Intensity Interval Training (HIIT)

• HIIT has been shown to increase growth hormone levels immediately after exercise.

• The effect of HIIT on long-term growth hormone levels is less clear.

Endurance Training

• Endurance training has not been shown to increase growth hormone levels immediately after exercise.

• The effect of endurance training on long-term growth hormone levels is less clear.

Nutrition and Growth Hormone Release

In this section, the speaker discusses how nutrition can help increase growth hormone release.

Protein

• Consuming protein before bed may help increase growth hormone release during sleep.

• Whey protein has been shown to be more effective than casein protein in increasing growth hormone release.

Carbohydrates

• Consuming carbohydrates before bed may decrease growth hormone release during sleep.

Fasting

• Intermittent fasting may help increase growth hormone release.

Non-Sleep Deep Rest and Exercise for Growth Hormone Release

In this section, the speaker discusses non-sleep deep rest techniques such as yoga nidra and hypnosis. The speaker also talks about exercise as a way to trigger growth hormone release.

Meditation and Melatonin

• Non-sleep deep rest techniques like yoga nidra and hypnosis may not put people into slow-wave sleep or delta waves.

• 20 minutes of traditional meditation can help access delta waves.

• Low doses of melatonin can trigger delta waves and growth hormone release in sleep.

Exercise for Growth Hormone Release

• Exercise has been shown to have enormous effects on growth hormone release in waking.

• Weight training or endurance training limited to about 60 minutes can lead to the greatest growth hormone releases.

• Warm up the body for about 10 minutes before starting exercise to accelerate the release of growth hormone once the hard work phase starts.

• High-intensity exercise that brings muscles close to failure but not pushing through those leads to anywhere from 300% to 500% increases in resting growth hormone levels.

Duration and Intensity of Exercise

• Cortisol levels go high enough if one exercises too long with weights or endurance exercise, inhibiting testosterone and estrogen pathways.

• Overexercising or exercising a lot can cause people to lose their menstrual cycles or experience suppressions in testosterone.

• The cutoff for hard work part is usually around 60 to 75 minutes.

Maximizing Growth Hormone Release in Sleep

This section discusses how to maximize growth hormone release during sleep through exercise and body temperature regulation.

Exercise and Blood Glucose Levels

• To maximize growth hormone release, it is important to not have blood glucose levels too high or too low.

• Eat sufficient energy for exercise but avoid eating too close to exercise or ingesting a lot of sugars during the exercise.

• Ingestion of a sports drink that contains caloric sugar immediately flat-lines the growth hormone levels.

Exercise Duration and Body Temperature Regulation

• Do training for 60 to 75 minutes to maximize growth hormone release.

• Taking body temperature back down to normal levels relatively quickly after exercise seems to be associated with big spikes in growth hormone.

• If body temperature remains too high for too long, then you don't get the effect of increased growth hormone.

• Bring body temperature back down by cooling off, taking a cool shower, using an ice pack, turning off the heat in the room, or going outside.

Effects of Growth Hormone on Memory and Cognition

• Growth hormone does not work alone; its effects are mediated by its effects on the liver.

• The liver releases insulin growth factor 1 (IGF-1), which triggers improvements in memory and learning after exercise.

• IGF-1 has positive effects on memory and cognition even though it does not increase neurogenesis in humans.

Sex-dependent Effects of Exercise on IGF-1 and Growth Hormone

• Certain patterns of exercise duration have different effects on IGF-1 and growth hormone depending on whether men or women do them.

• 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 around 60 minutes total.

Exercise and Growth Hormone Release

In this section, the speaker discusses how exercise can lead to growth hormone release and the conditions required for it.

Warm-up and Exercise

• To get growth hormone release during exercise, warm up before exercising.

• Do exercises that have been discussed previously.

• Women will get maximum benefit in terms of growth hormone and IGF-1 in the first 30 minutes of exercise.

• Men need to keep going for the entire 60 minutes to get the same benefits.

Cooling Down

• After exercising, cool down properly.

• Don't make the exercise last so long that you don't get an increase in growth hormone the following night.

Supplements for Growth Hormone Release

In this section, the speaker talks about supplements that can increase growth hormone levels.

Arginine

• Arginine is an amino acid that can increase growth hormone levels substantially.

• The amount of arginine required to get big growth hormone release increases is pretty substantial.

• The prerequisite for taking arginine is low blood glucose.

• The amounts of arginine that people take are anywhere from three grams to 10 grams or sometimes even more.

• Taking more than nine grams of arginine can blunt growth hormone release.

• Taking arginine can dramatically increase growth hormone release by anywhere from 100% on the low-end but basically from 400 to 600% above baseline.

Ornithine

• Ornithine is another amino acid that can increase growth hormone levels.

• Arginine and ornithine are often used together in supplements.

Vasodilation and Heart Conditions

In this section, the speaker talks about the effects of arginine on vasodilation and how it can be a serious issue for people with heart conditions.

Arginine and Vasodilation

• Arginine has the effect of dilating arterials and increasing blood supply.

• The arginine pathway is involved in vasodilation.

• Increasing arginine levels with the specific goal of increasing growth hormone release will also have the effect of dilating blood vessels.

Heart Conditions

• For people with heart conditions, increased vasodilation caused by taking arginine can be a serious issue.

Arginine and L-Citrulline

This section discusses the effects of arginine and L-citrulline on vasodilation, growth hormone levels, and blood pressure.

Arginine Effects

• Arginine has effects on vasodilation and can increase growth hormone levels.

• Taking arginine before exercise can short circuit or clamp the effects of exercise on growth hormone.

• Arginine may not be the best way to increase arginine in the blood due to how it's metabolized in the gut.

L-Citrulline Effects

• L-citrulline has powerful effects on vasodilation and potentially on growth hormone levels via the arginine pathway.

• It acts as a donor for arginine and can lead to even bigger increases in arginine than taking arginine itself.

• L-citrulline will lower blood pressure due to its effect on dilating blood vessels.

Examine.com

• Examine.com is a recommended resource for information about supplements like L-citrulline and arginine.

• There are many benefits associated with taking L-citrulline, including increased power output in the gym, reduced fatigue, big increases in nitric oxide, notable effects on plasma arginine, increased training volume, decreased arterial stiffness, decreased c-reactive protein, etc.

Growth Hormone Profile Changes with Age

This section discusses how the profile of growth hormone changes as we age.

Aging Effects

• The profile of growth hormone changes as we age.

• Understanding how it changes is important when considering ways to increase growth hormone levels.

Growth Hormone and Temperature

In this section, the speaker discusses how growth hormone levels vary from person to person and how getting older does not necessarily mean that testosterone levels are dropping. The speaker also talks about the age-related decline in growth hormone and how it can be offset through behaviors such as exercising, optimizing sleep, and not eating too close to bedtime. Additionally, the speaker explains how temperature has a profound effect on growth hormone release.

Growth Hormone Release

• Growth hormone is released in the brain, specifically in the hypothalamus.

• The hypothalamus controls basic functions such as sexual behavior, temperature regulation, circadian behavior (when you want to be awake or asleep), aggression, etc.

• Growth hormone-releasing hormones come from neurons in the hypothalamus which communicate with the pituitary gland to release growth hormone.

• Growth hormone acts on different tissues such as muscle, liver, cartilage, body fat making them use energy.

Temperature and Growth Hormone Release

• Studies show that increasing temperature can increase growth hormone levels.

• Increasing temperature is risky because it doesn't take much of a temperature increase in the brain to cook neurons which cannot come back. People can die from hyperthermia.

Increasing Levels of Growth Hormone Dramatically

In this section, the speaker discusses a way anyone can increase their levels of growth hormone dramatically by increasing their body's core temperature.

Increasing Body's Core Temperature

• Exercise increases growth hormone levels by 300% to 500%.

• Not everyone should engage in the behaviors that increase body temperature.

• Behaviors such as exercising, optimizing sleep, and not eating too close to bedtime can offset the age-related decline in growth hormone completely.

Sauna and Growth Hormone Release

In this section, the speaker discusses how sauna can increase the release of growth hormone and other hormones. The speaker talks about the size of the effects that are reported in literature.

Effects of Temperature Increase

• Warming up a few degrees before exercise leads to bigger and quicker increases in growth hormone during exercise.

• Increasing body temperature by entering saunas that are between 176°F (80°C) to 210-215°F has been shown to increase growth hormone release 16 fold or 1600%.

• High heat is dangerous, so it's important to clear this with your doctor before trying it out.

Endocrine Effects of Repeated Sauna

• A pattern was described in a study where getting into the sauna for 20 minutes followed by a 30-minute cooling period, then another 20 minutes sauna led to a five-fold increase in growth hormone.

• Doing this day after day on the third day led to huge increases of up to 16 fold.

• Standard sauna can be useful. If you don't have access to a sauna, one way people do this is by wearing plastics or bodysuits that are fairly inexpensive.

Other Considerations

• Dilation of blood vessels, sweating, and arginine also occur when exposed to high heat.

• Spending long periods at high heat can be dangerous and cause damage to tissues.

• Some people wrap themselves in garbage bags and then throw on sweats and a hoodie if they don't have access to a sauna. However, overheating can be fatal, so it's important to be careful.

Sauna and Hormones

In this section, Dr. Rhonda Patrick discusses the effects of sauna on hormones, particularly growth hormone and cortisol.

Sauna and Growth Hormone

• Sauna can increase growth hormone levels significantly.

• Increased activity of neurons within the hypothalamus that stimulate growth hormone release from the pituitary is responsible for this effect.

• Heat seems to have positive effects on growth hormone levels.

Sauna and Cortisol

• Sauna leads to a significant decrease in cortisol levels.

• Cortisol is a stress hormone that should be released early in the day when you wake up.

Study on Thermal Stress and Cold Water Immersion

• A recent study found that sauna led to a significant decrease in cortisol levels but did not change testosterone, DHEA or prolactin levels.

• The cold affected some of these hormones but the results were more mixed.

Prescription Hormones

In this section, Dr. Rhonda Patrick talks about prescription hormones and what people should consider before taking them.

Synthesized Hormones

• Most of the hormones we make have been synthesized and are available in little bottles or ampules that people can inject.

Considerations Before Taking Prescription Hormones

• Talk to a physician before taking any prescription hormones as they are only legally available through a physician.

• Injecting something will shut down your own production of that hormone. If you're willing to sustain a period without a given hormone, some people can do things and then stop taking them.

Peptides and Their Effects

In this section, Dr. Patrick explains what peptides are and how they work in the body. She also discusses how certain peptides can be used to stimulate the release of hormones like growth hormone and thyroid hormone.

Peptides: What They Are and How They Work

• Peptides are strings of amino acids that resemble hormones or other peptides enough to produce similar effects when injected.

• Polypeptides are longer strings of amino acids that fall under the category of peptides.

• Growth hormone-releasing hormone is an example of a peptide that stimulates growth hormone production from the pituitary gland.

• Sermorelin is a subset of growth hormone-releasing hormone that can be injected to stimulate growth hormone production.

Effects of Injecting Peptides

• Injecting stimulating hormones like sermorelin can lead to increased production of growth hormone, which can have positive effects on recovery time, healing rates, and tissue regeneration.

• Some peptides have been shown to change gene expression programs in the body, leading to long-term changes in hormone production even after stopping injections.

• However, injecting too much growth hormone or using it for extended periods can lead to negative effects like tumor growth.

Understanding Thyroid Hormone

In this section, Dr. Patrick explains what thyroid hormone is and how it works in the body.

What Is Thyroid Hormone?

• Thyroid hormones are produced by the thyroid gland and play a crucial role in regulating metabolism throughout the body.

• The two main thyroid hormones are T3 and T4, which are produced in response to signals from the pituitary gland.

How Thyroid Hormone Works

• Thyroid hormone works by binding to receptors on cells throughout the body, which then leads to changes in gene expression and metabolism.

• Low levels of thyroid hormone can lead to symptoms like fatigue, weight gain, and depression, while high levels can lead to symptoms like anxiety and weight loss.

Tips for Better Sleep and Understanding Hormones

In this section, the speaker provides tips for better sleep and discusses the interplay between hormones and the brain.

Tips for Better Sleep

• Supplementing with arginine may help with getting an early phase of sleep.

• Adequate exercise, warming up properly, not making the exercise too long or too intense can also help with better sleep.

• Deliberate, safe hyperthermia (such as sauna use) may be useful.

Understanding Hormones

• The speaker concludes a month-long discussion on hormones by emphasizing that understanding thyroid hormone, growth hormone, estrogen, testosterone is important.

• The speaker highlights the importance of understanding cholecystokinin and ghrelin in relation to eating habits.

• The interplay between hormones and the brain is bidirectional. Hormones influence all tissues of the body but also tell the brain whether or not to eat more or grow more or think more.

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Conclusion

The speaker thanks the audience for their time and attention, and encourages an interest in science.

• The speaker thanks the audience for their time and attention, and above all, for their interest in science.