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Essentials: How to Control Your Metabolism by Thyroid & Growth Hormone

Mar 6, 2025 35m 14s 22 insights
In this Huberman Lab Essentials episode, I explain how two key hormones control metabolism and discuss tools to enhance their levels to improve metabolic health. I discuss the pathways through which the brain and body interact to produce thyroid hormone and growth hormone, and how these hormones influence essential processes like tissue growth and repair, body composition, and energy production. I explain how thyroid hormone levels are influenced by key nutrients, such as iodine, selenium, and L-tyrosine. I also explain how practices such as exercise, sleep, meditation and sauna can offset age-related declines in growth hormone, to optimize overall hormone health and metabolism. Read the full episode show notes at hubermanlab.com. Huberman Lab Essentials are short episodes focused on essential science and protocol takeaways from past full-length Huberman Lab episodes. Watch or listen to the full-length episode at ⁠⁠⁠⁠⁠hubermanlab.com⁠⁠⁠⁠⁠.
Actionable Insights

1. Optimize Sleep for Growth Hormone

To maximize natural growth hormone release for tissue repair and metabolism, prioritize getting into slow-wave (deep) sleep and ensure blood insulin and glucose levels are relatively low. Avoid eating within two hours of bedtime to prevent suppression of growth hormone.

Actively pursue behaviors like regular exercise, avoiding eating too close to bedtime, and optimizing sleep to offset the age-related decline in growth hormone, especially for those in their thirties and forties.

3. Optimize Exercise for Growth Hormone

To maximize growth hormone release from exercise, limit weight or endurance training to about 60 minutes and perform a proper 10-minute body-warming warmup, as body temperature is a prerequisite for optimal growth hormone secretion.

4. Train Near Failure for GH

For weight-bearing exercise, aim to get close to muscular failure without necessarily pushing through or going to complete failure, as this intensity can significantly increase growth hormone levels (300-500%) both at rest and during subsequent sleep.

5. Exercise with Low Blood Glucose

Maintain relatively low blood glucose levels before and during exercise to maximize growth hormone release; avoid eating too close to a workout or ingesting sugary sports drinks during it, as caloric sugar can flatline growth hormone levels.

6. Cool Down Post-Exercise for GH

After exercise, cool your body temperature back down to normal levels relatively quickly to sustain the beneficial spikes in growth hormone and ensure the second increase in growth hormone the following night.

7. Use Sauna for Growth Hormone

Engage in deliberate hyperthermia via sauna sessions (20-30 minutes at 80-100 degrees Celsius) to dramatically increase growth hormone release, potentially by 16-fold.

8. Sauna Protocol for GH Release

For maximal growth hormone increase from sauna, follow a protocol of 20 minutes in the sauna, 30 minutes of cooling, then another 20 minutes in the sauna, repeated for three consecutive days to achieve up to a 16-fold increase.

9. Exercise Extreme Caution with Sauna

Exercise extreme caution with deliberate hyperthermia (sauna) due to the significant risks of overheating, which can cause brain damage or death; not everyone should engage in these behaviors.

10. Ensure Sufficient Iodine Intake

Consume sufficient iodine to support thyroid hormone production, as it is essential for metabolism and tissue buildup. Good sources include sea salt, kelp, seaweed, and iodized table salt.

11. Get Enough L-Tyrosine

Ensure sufficient L-tyrosine intake, as it combines with iodine in the thyroid to produce T3 and T4 hormones, which are crucial for metabolism. L-tyrosine can be found in meat, nuts, and some plant-based sources.

12. Consume Enough Selenium

Consume enough selenium to support thyroid hormone production, as it facilitates the interaction between L-tyrosine and iodine. The average recommended intake for adults is about 155 micrograms, while children need less (30-40 micrograms for 14 or younger).

13. Incorporate Selenium-Rich Foods

To increase selenium intake, consider eating Brazil nuts (6-8 contain ~550 micrograms), fish, ham, pork, beef, turkey, chicken, cottage cheese, eggs, or brown rice, as these foods contribute to healthy thyroid function.

14. Optimize Sleep Temperature

Control your sleeping environment’s temperature to optimize sleep quality and promote slow-wave and REM sleep. Aim for a cooler temperature at the beginning and middle of the night, warming up towards waking.

15. Meditate for Growth Hormone Release

Engage in meditation practices that induce slow-wave delta-type frequency brain activity, as this can mimic slow-wave sleep and potentially increase growth hormone release.

16. Supplement Arginine for GH

Consider supplementing with 3 to 9 grams of the amino acid arginine, either before bedtime or exercise, to substantially increase growth hormone levels (400-600%), ensuring blood glucose is low for optimal effect.

17. Arginine and Exercise Not Additive

Do not combine arginine supplementation with exercise expecting additive growth hormone increases, as the combined effect is capped at similar levels (300-500% increases) as either method alone.

18. Be Aware of Arginine Side Effects

Be aware that taking 9 grams of oral arginine can cause gastrointestinal disturbances such as nausea or vomiting.

19. Consult Doctor for Thyroid Concerns

If concerned about excessively high or low thyroid hormone levels, research the symptoms and consult a physician for diagnosis and treatment options.

20. Utilize David Protein Bars

Consider using David protein bars as a convenient snack to meet protein goals (28 grams protein, 150 calories, 0 sugar), especially when out of the house or traveling.

21. Understand Prescription Peptides

Be aware that prescription peptides like sermorelin can stimulate the release of growth hormone from the pituitary, acting as a secretagogue or mimic of growth hormone-releasing hormone.

22. Be Cautious with Peptides

Understand that while peptides like sermorelin can increase growth hormone, they may shut down natural production and can activate long-lived gene expression programs, potentially leading to the growth of all tissues, including unhealthy tumors.