April 26, 2021 • 1hr 46min

How to Control Your Metabolism by Thyroid & Growth Hormone

Huberman Lab

This episode focuses on metabolism and how thyroid hormone and growth hormone control our metabolic processes. Dr. Huberman explains that metabolism isn't just about burning energy, but involves converting energy from different sources into fuels for building and repairing tissues like muscle, brain, and tendons, as well as mobilizing energy from body fat storage. He discusses the roles of iodine, selenium, and salt for thyroid health, and how specific exercise protocols, amino acids, and temperature can dramatically shift levels of growth hormone release both during waking hours and sleep. The episode also covers the current landscape of prescription compounds, peptides, and other factors for modulating thyroid and growth hormone levels, along with some of their potential risks.

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Key Takeaways

Thyroid hormone and growth hormone are two key hormones that control metabolism - they regulate energy use, tissue growth and repair, and body composition
Iodine, selenium, and L-tyrosine are essential nutrients for thyroid hormone production - many people may be deficient, especially those on "clean" diets
Growth hormone release declines significantly (2-3 fold) between ages 30-40 - but there are ways to naturally boost levels
Exercise can increase growth hormone by 300-500% - 60-75 minutes of resistance or endurance training is optimal
Sauna use can increase growth hormone up to 1600% - 20 minutes at 175-210°F followed by cooling is most effective
Arginine and L-citrulline supplements can boost growth hormone 100-600% - but have other effects like lowering blood pressure
Low-dose melatonin (500mcg) may enhance slow wave sleep and growth hormone release
Avoiding food 2-3 hours before bed and optimizing sleep helps maximize natural growth hormone pulses

Introduction

This episode focuses on metabolism and how thyroid hormone and growth hormone control our metabolic processes. Dr. Huberman explains that metabolism isn't just about burning energy, but involves converting energy from different sources into fuels for building and repairing tissues like muscle, brain, and tendons, as well as mobilizing energy from body fat storage.

He discusses the roles of iodine, selenium, and salt for thyroid health, and how specific exercise protocols, amino acids, and temperature can dramatically shift levels of growth hormone release both during waking hours and sleep. The episode also covers the current landscape of prescription compounds, peptides, and other factors for modulating thyroid and growth hormone levels, along with some of their potential risks.

Topics Discussed

Thyroid Hormone Function and Production (20:04)

Thyroid hormone (T3) promotes metabolism in tissues throughout the body
It controls energy use, tissue growth/repair, and body composition
Iodine, L-tyrosine, and selenium are essential for thyroid hormone production
"Thyroid hormone of t three is to promote metabolism. And that doesn't just mean the consumption of energy, it means the utilization of energy, including the buildup of tissues."

Iodine, Selenium and L-Tyrosine for Thyroid Health (22:04)

Iodine comes from sea salt, kelp, seaweed - most get enough from diet
Selenium is often deficient - Brazil nuts are the best source
L-tyrosine is needed to combine with iodine to make thyroid hormone
Those on "clean" diets may be at risk of deficiency in these nutrients

Growth Hormone Function and Release (48:39)

Growth hormone promotes tissue growth, repair, and metabolism
It is released in pulses, especially during slow wave sleep
Levels decline 2-3 fold between ages 30-40
Delta brain waves trigger growth hormone release from the pituitary

Exercise Effects on Growth Hormone (1:04:35)

60-75 minutes of resistance or endurance exercise can increase GH 300-500%
Proper warm-up and keeping blood glucose low enhances the effect
Women get peak GH release in first 30 minutes, men need full 60 minutes
Cooling down after is important to get a second GH pulse during sleep

Supplements to Boost Growth Hormone (1:14:10)

Arginine can increase GH 100-600%, but has other effects like vasodilation
L-citrulline may be more effective than arginine itself
3-9 grams of arginine before sleep or exercise can boost GH
Combining arginine and exercise does not have an additive effect

Heat Exposure for Increasing Growth Hormone (1:26:00)

Sauna use at 175-210°F for 20 minutes can increase GH up to 1600%
Protocol: 20 min sauna, 30 min cooling, repeat 1-2 more times
Likely works by stimulating hypothalamic neurons that trigger GH release
"Getting into environments where it's very hot for short periods of time, anywhere from 20 minutes to 30 minutes, where the temperature is 80 degrees celsius to 100 degrees celsius, or 175 degrees fahrenheit, more or less, to about 210 degrees fahrenheit, more or less has been shown to increase growth hormone release 16 fold. That's right, 16 fold. That's 1600%."

Optimizing Sleep for Growth Hormone Release (54:49)

Avoid eating 2-3 hours before bed to keep blood glucose low
Delta wave brain activity during slow wave sleep triggers GH release
Low dose melatonin (500mcg) may enhance slow wave sleep and GH release
20 minutes of meditation may help access delta wave states

Prescription Growth Hormone and Peptides (1:36:00)

Synthetic growth hormone is available by prescription
Peptides like Sermorelin can stimulate natural GH production
These can shut down natural hormone production
Long-term use may alter gene expression
Popular in entertainment/sports but carry risks

Conclusion

Dr. Huberman concludes by emphasizing that thyroid hormone and growth hormone are incredibly powerful compounds that dictate our metabolism, body composition, tissue repair, and cognitive function. While there are many ways to naturally optimize these hormones through diet, exercise, sleep, heat exposure, and targeted supplementation, he cautions that more extreme interventions like peptides or hormone replacement therapy carry risks and should only be done under medical supervision.

He encourages listeners to use this knowledge to make informed decisions about supporting their hormone health, while always prioritizing safety. The key takeaway is that we have significant control over our hormone levels through lifestyle factors, giving us the ability to maintain metabolic health as we age.