In this episode of Huberman Lab Essentials, Dr. Andrew Huberman, Professor of Neurobiology and Ophthalmology at Stanford School of Medicine, explores two of the body’s most influential hormonal systems: thyroid hormone and growth hormone. These two hormone systems play crucial roles in regulating metabolism, which extends far beyond just weight management to include tissue repair, cognitive function, and overall vitality throughout the lifespan.
Dr. Huberman breaks down the biological mechanisms that govern these hormonal pathways and explains how they interact with various tissues in the body to promote growth, repair, and energy utilization. What makes this episode particularly valuable is its focus on practical, accessible ways to optimize these systems naturally through diet, exercise, sleep, and other behavioral modifications.
The insights shared in this episode provide a science-based toolkit for anyone looking to improve their metabolic health, enhance recovery, maintain cognitive function, and potentially offset some of the age-related declines in hormonal function. From nutrition protocols to exercise strategies and sleep optimization, Dr. Huberman offers specific, actionable recommendations that can be implemented immediately.
Watch the Full Huberman Lab Episode
Core Concepts
The Thyroid Hormone Pathway: Brain to Body
Thyroid hormone operates through a cascade that begins in the brain. Dr. Huberman explains that neurons in the hypothalamus release thyroid releasing hormone, which signals the pituitary gland to release thyroid stimulating hormone (TSH). This TSH then triggers the thyroid gland (located near the Adam’s apple) to release two hormones: T4 and T3, with T3 being the more active form.
This pathway is critical because thyroid hormone regulates metabolism throughout the body—not just energy consumption, but also tissue building and repair. T3 acts on muscles, liver, cartilage, bone, and fat tissues to control how efficiently the body utilizes energy from fats and sugars. Proper thyroid function means better energy use, tissue repair, and even cognitive performance.
The practical implication is significant: maintaining optimal thyroid function supports lean muscle mass, efficient fat metabolism, and overall metabolic health. This explains why individuals with lower thyroid function often struggle with weight management and reduced energy levels.
Growth Hormone: The Repair and Regeneration System
Similar to thyroid hormone, growth hormone follows a brain-to-body pathway. Growth hormone releasing hormone from the hypothalamus tells the pituitary to release growth hormone into the bloodstream, where it acts on tissues throughout the body to increase metabolism and promote tissue repair and growth.
Dr. Huberman emphasizes that growth hormone is not just important during developmental years; it plays a crucial role throughout adulthood in tissue repair, metabolism, and fat utilization. As we age (particularly between 30-40 years), our natural growth hormone production decreases by two to threefold, which contributes to slower recovery, increased body fat, and reduced metabolic rate.
Understanding this decline makes the case for implementing strategies to naturally boost growth hormone levels. The exciting insight Dr. Huberman shares is that through specific behaviors and practices, we can potentially offset this age-related decline completely, allowing for better recovery, metabolism, and tissue health as we age.
Sleep’s Critical Role in Hormonal Release
One of the most important insights from the episode concerns the relationship between sleep and growth hormone. Dr. Huberman explains that growth hormone is primarily released during the early phases of sleep, specifically during slow-wave or “deep” sleep. This release is characterized by delta wave activity in the brain, and it requires two specific conditions: being in slow-wave sleep and having relatively low blood insulin and glucose levels.
This connection has direct practical implications. Eating close to bedtime (within 2 hours) elevates insulin and glucose, which suppresses growth hormone release. Additionally, factors that enhance slow-wave sleep will likely increase growth hormone release.
This understanding provides clear guidance for optimizing sleep not just for rest, but as a critical window for hormonal regulation that affects daytime performance, recovery, and metabolic health.
The Temperature-Hormone Connection
Perhaps one of the most fascinating connections Dr. Huberman discusses is the relationship between body temperature and growth hormone release. The hypothalamus contains neurons that regulate both temperature and growth hormone release, and these systems are closely intertwined.
Research cited shows that controlled hyperthermia, such as sauna use, can dramatically increase growth hormone levels—up to 16-fold (1600%) with consistent practice. The specific protocol involved 20 minutes of sauna exposure, followed by 30 minutes of cooling, then another 20 minutes of sauna, repeated over multiple days.
This temperature manipulation represents a powerful tool for potentially boosting growth hormone naturally, though Dr. Huberman appropriately emphasizes caution given the risks associated with excessive heat exposure.
Actionable Protocols
Optimizing Thyroid Function
Ensure adequate iodine intake:
- Primary sources: Sea salt, kelp, seaweed
- Most table salt is iodized
Consume sufficient selenium:
- Recommended intake: ~155 micrograms daily (varies by country)
- Brazil nuts (6-8 nuts provide ~550 micrograms)
- Other sources: Fish, ham, turkey, chicken, beef, cottage cheese, eggs, brown rice
- Children require lower amounts (30-40 micrograms for those under 14)
Include L-tyrosine in your diet:
- Sources: Meat, nuts, and some plant-based foods
- Functions as a precursor to thyroid hormone
Consider meal timing:
- Thyroid hormone increases glucose uptake by tissues
- Supports efficient energy utilization for tissue repair
Boosting Growth Hormone Naturally
Sleep optimization:
- Prioritize quality slow-wave sleep (early part of sleep cycle)
- Avoid eating within 2 hours of bedtime to keep insulin/glucose low
- Focus on consistent sleep schedule to support natural hormonal rhythms
Exercise protocol:
- Duration: Limit sessions to approximately 60 minutes
- Include a 10-minute warm-up to increase body temperature
- For strength training: Work to near-failure but not complete failure
- For endurance: Maintain significant effort level throughout
- Cool down properly after exercise
- Avoid sugary sports drinks during/immediately after workouts
- Potential effect: 300-500% increase in growth hormone levels
Temperature manipulation (caution advised):
- Protocol: 20 minutes sauna (80-100°C), 30 minutes cooling, 20 minutes sauna
- Repeat pattern for multiple days for maximum effect
- Potential effect: Up to 1600% increase in growth hormone with consistent practice
- IMPORTANT: Approach with extreme caution due to hyperthermia risks
Supplementation approach:
- Arginine: 3-9 grams (not more)
- Take when blood glucose is low for maximum effect
- Consider timing (pre-sleep or pre-exercise)
- Note: Does not stack additively with exercise effects
- Potential effect: 400-600% increase in growth hormone release
Meditation practice:
- Focus on meditation styles that promote delta wave brain activity
- Similar brain states to slow-wave sleep can potentially support growth hormone release
Implementation Guide
Step 1: Start with Sleep Fundamentals
The foundation for optimizing both thyroid and growth hormone begins with sleep. Implement a consistent sleep schedule and avoid late meals. This simple change requires no supplements or specialized equipment and can have profound effects on hormonal balance.
- Set a consistent bedtime and wake time
- Stop eating 2-3 hours before sleep
- Create a cool, dark sleeping environment
- Consider tracking sleep quality with available technology
Step 2: Nutrition Adjustments
Once sleep is optimized, focus on nutrition to support thyroid function:
- Check your diet for iodine-rich foods and consider whether you’re using iodized salt
- Add selenium-rich foods (Brazil nuts are the simplest addition)
- Ensure sufficient protein intake for L-tyrosine
- Time your meals to support exercise performance and recovery
Step 3: Exercise Implementation
Design an exercise regimen specifically to support growth hormone release:
- Schedule 45-60 minute sessions (not longer)
- Include a proper 10-minute warm-up
- Perform high-intensity work without reaching complete failure
- Include proper cool-down
- Avoid sugary drinks during and immediately after
Step 4: Advanced Protocols (for those ready)
After mastering the fundamentals, consider:
- Exploring sauna use (if accessible and appropriate for your health status)
- Consider arginine supplementation (consult healthcare provider)
- Integrate meditation practices that promote delta wave brain activity
Start Small
For beginners, focus on these three simple adjustments:
- Stop eating 2-3 hours before bedtime
- Add 2-3 Brazil nuts to your daily diet
- Include a proper warm-up and cool-down with your existing exercise routine
Key Quotes
“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), and we know that that’s healthy.”
“The reason you can recover more quickly from injuries if you have a healthy thyroid and healthy thyroid pathways is because you can consume energy that energy is diverted toward bone repair and muscle repair and cartilage repair.”
“It’s actually between ages 30 and 40 that the amount of growth hormone that you release each night is reduced by two to threefold… the things that we’re supposed to be doing anyway like exercising, like trying not to eat too close to bedtime, trying to optimize sleep—all of these can actually offset the two to threefold decrease.”
“Exercise has to be of particular duration and intensity in order to get growth hormone release… getting close to that final repetition where you can’t complete them but not pushing through those or even going to failure but getting close leads to anywhere from a 300 to 500% increase in resting growth hormone levels.”
“These hormones… dictate how many nutrients we can eat and make use of. They can pull from body fat stores, repair muscle, repair cartilage. They really are incredible compounds and they are actionable.”
Summary and Next Steps
This Huberman Lab Essentials episode provides a comprehensive framework for understanding and optimizing two key metabolic hormone systems. By implementing the recommended sleep, nutrition, exercise, and temperature protocols, you can potentially counteract age-related hormonal declines and improve overall metabolic health.
The most accessible starting points include optimizing sleep timing, adjusting meal timing relative to sleep, ensuring adequate intake of key nutrients like selenium and iodine, and structuring exercise sessions to maximize hormonal response.
For those interested in diving deeper into these topics, Dr. Huberman’s full episodes on sleep optimization, nutrition, and exercise provide more detailed protocols. Additionally, exploring resources on meditation practices that promote delta wave activity could complement the strategies outlined in this episode.
Remember that hormonal health is highly individual, and consulting with healthcare providers before making significant changes to diet, exercise, or implementing protocols like sauna use is always recommended, especially for those with existing health conditions.
Quick Reference Guide
Thyroid Support:
- Iodine: Sea salt, kelp, seaweed
- Selenium: 155μg daily (Brazil nuts, fish, eggs)
- L-tyrosine: Meat, nuts
Growth Hormone Optimization:
- Sleep: No food 2hrs before bed, prioritize deep sleep
- Exercise: 60min sessions, 10min warm-up, near-failure effort
- Temperature: Sauna protocol (with caution) – 20min sauna, 30min cooling, 20min sauna
- Supplements: Arginine 3-9g when glucose is low
Daily Implementation:
- Stop eating 2-3hrs before sleep
- Add Brazil nuts to daily diet
- Structure exercise for hormonal response
- Consider sauna use (if appropriate)
- Avoid sugary drinks during/after exercise