Dr. Kyle Gillett — A dual board-certified physician (family medicine and obesity medicine) specializing in hormone health and optimization for men and women across the lifespan.
The gist
In this Huberman Lab Essentials episode, Andrew Huberman and Dr. Kyle Gillett discuss a practical framework for hormone health. Gillett lays out his 'big six pillars'—diet, exercise, stress, sleep, sunlight, and spirit—and explains how to push your doctor for better lab work using symptoms rather than diagnoses. The conversation covers testosterone in both men and women, DHT and hair loss, PCOS diagnosis and treatment, TRT risks like sleep apnea, and how marijuana, alcohol, caffeine, and even dairy protein affect hormones. The back half is a candid guide to peptides—BPC-157, melanotan/PT-141, growth hormone peptides—including safety, sourcing dangers, and when to avoid them entirely.
Big reveals
- Caloric restriction raises testosterone in obese/metabolic-syndrome men but actually DECREASES it in young, lean, healthy men.
- Starting TRT drastically raises the risk of sleep apnea, in a dose-dependent fashion, even in men who had normal testosterone beforehand.
- Testosterone doesn't cause prostate cancer, but it will grow an existing one—and by age 80 at least 50% of men have a prostate cancer on autopsy.
- Most women actually have far more total testosterone than estradiol, and significantly more DHEA than either.
- Gillett wagers a Russian gymnast who fully healed a ruptured Achilles in one month was likely using BPC-157 or something similar.
- Strong warning: non-prescription BPC-157 is often contaminated with LPS, and the 'tingling/fever' people feel is inflammation, not the peptide 'working.'
- Casein (milk protein) and gluten act as mu-opioid receptor agonists in the gut and can raise prolactin, which suppresses testosterone.
Things worth remembering
- The 'big six pillars' of hormone health: diet, exercise, stress, sleep, sunlight, and spirit—with diet and resistance training the two most powerful.
- Gillett recommends blood testing every 3 to 6 months for prevention, done both fasted and non-fasted.
- Huberman cites a target of 150–180 minutes minimum of zone-two cardio per week.
- The androgen receptor gene sits on the X chromosome, so men inherit it from their mothers.
- Dutasteride mesotherapy—localized scalp injections—can fight hair loss while limiting whole-body DHT side effects.
- PCOS is diagnosed via the Rotterdam criteria (androgen excess, insulin resistance, polycystic ovaries) and most women find out in their 30s.
- Smoked marijuana raises aromatase (converting testosterone to estrogen), while THC/CBD alone do not lower testosterone.
- Bremelanotide/PT-141 (a melanotan peptide) has FDA-approved indications, including low libido in premenopausal women.
- Caffeine has a negligible effect on hormones unless it disrupts your sleep.