The guest
Dr. Kyle Gillett: A dual board-certified physician in family medicine and obesity medicine who specializes in hormone optimization and treats patients across all ages and goals.
What this episode covers
This Huberman Lab episode is a deep, chronological tour of male hormone optimization, starting at the two puberties of early life and moving through the teens, 20s, 30s, and into old age. Gillett lays out a hierarchy of tools: behavioral foundations (sleep, sunlight, movement, stress management, social connection), then nutrition, then supplements, then peptides, and finally prescription drugs and exogenous hormones. He gives specific dosing guidance for supplements like creatine, l-carnitine, boron, tongkat ali, and fadogia agrestis, and explains the mechanics of TRT, hCG, clomiphene, and DHT-blocking hair-loss drugs. The conversation repeatedly stresses getting bloodwork, working with a qualified physician, and judging subjective markers like libido, energy, and recovery. It also covers the hormonal downsides of porn, alcohol, cannabis, nicotine, overtraining, and plastics.
Recommended on this episode
ProductRecommended
Creatine monohydrate
“I take 5 grams a day of creatine monohydrate. I do it for the tissue volumizing effects”
“I take 5 grams a day of creatine monohydrate. I do it for the tissue volumizing effects, so for exercise benefits, but also for the cognitive effects.”— Andrew Huberman
ProductRecommended
Tongkat ali (Long Jack)
“I take 400 milligrams of tongkat ali per day... I've been taking it for years. And I rather like that the effects.”
“I take 400 milligrams of tongkat ali per day. I take it early in the day because it has a bit of a stimulant effect”— Andrew Huberman
Also referenced (named, not recommended)
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Betaine
“Some people are nonresponders to creatine, so you can increase that to 10 grams, or you can use its cousin betaine to help with amino acid synthesis”— Kyle Gillett
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L-carnitine
“Usually, I recommend for oral l-carnitine between 1,000 milligrams and up to 4,000 or 5,000 milligrams.”— Kyle Gillett
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Vitamin D3
“Let's briefly mention vitamin D, which is also a hormone. And if you have deficient vitamin D and you replace it, then you will optimize your testosterone.”— Kyle Gillett
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Boron
“if you have a very high SHBG, boron can acutely help lower it usually in a dose of 5 to 12 milligrams per day.”— Kyle Gillett
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Fadogia agrestis
“I've been taking fadogia for some period of time. All my markers and tests indicate that there's no toxicity. But I've been taking 600 milligrams per day”— Andrew Huberman
ProductReferenced
Ibutamoren (MK-677)
“Ibutamoren is a long-acting-- so it has a long half life, also known as MK-677. It was studied mostly in growth hormone deficiency.”— Kyle Gillett
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Tesamorelin
“Tesamorelin is one of them, sermorelin is another one, and CJC is another common one. I believe those are all in the class of GHRH-like peptides”— Kyle Gillett
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BPC-157
“other people, for instance, are taking peptides like BPC 157 to try and improve tissue healing and recovery.”— Andrew Huberman
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Tadalafil (Cialis)
“Tadalafil is a very underrated medication... in general, I recommend no higher than 10 milligrams a day-- usually just two or 5 milligrams.”— Kyle Gillett
ProductReferenced
Clomiphene (Clomid)
“The Clomid, or clomiphene, there's two main... diastereomers. And one of them is enclomiphene and one of them is zuclomiphene.”— Kyle Gillett
ProductReferenced
Finasteride (Propecia)
“Finasteride inhibits 1 and 2. Dutasteride actually inhibits all three.”— Kyle Gillett
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Dutasteride
“Dutasteride actually inhibits all three. And finasteride inhibits the isoenzyme that is in genital skin”— Kyle Gillett
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Saw palmetto
“saw palmetto is also a 5-alpha reductase inhibitor, but only a couple of the isoenzymes. There's three main isoenzymes”— Andrew Huberman
ProductReferenced
Ketoconazole (topical)
“many people that have just a bit of predisposition, they can use things that are topical anti-androgens. Ketoconazole is one of them, caffeine is actually another one.”— Kyle Gillett
Big reveals from this episode
- Gillett explains there are two puberties: the first occurs in the first three months of life, driven largely by DHEA.
- Daily or more-frequent masturbation can be hormonally detrimental via prolactin spikes that inhibit LH; for most people the optimal porn amount is zero.
- It is not hormonally helpful to regularly train vigorously for longer than an hour.
- Gillett says there is almost never a justified case for men in their 20s with normal testosterone to take exogenous testosterone.
- Fasting raises growth hormone but downstream receptor sensitivity drops, so fasting for GH optimization in healthy people is not helpful.
- Huberman shares that sermorelin gave him deep but truncated sleep and later spiked his PSA, so he avoids frequent use.
- Huberman recounts that turmeric crushed his DHT and vitality, and he now avoids both turmeric and bioperine 'like the plague.'
- Gillett tests his own tap and filtered water for microplastics and added processed mac and cheese to his pregnancy avoid-list over phthalates.
Worth remembering
- Childhood obesity triggers early puberty because excess body fat raises leptin, which activates the hypothalamus.
- Erectile dysfunction is called the 'canary in the coal mine' because arterial plaque often shows up in the genitals before the coronaries.
- The 'dopamine wave pool' analogy: higher peaks create deeper troughs and can drain your overall dopamine supply.
- All men inherit their single androgen receptor gene from their mother because it sits on the X chromosome.
- Boron is depleted in many soils but high in Greece and Turkey, possibly explaining higher testosterone reference ranges there.
- Non-synthetic hCG is refined from the urine of first-trimester pregnant women, since the placenta produces it.
- hCG closely resembles thyroid-stimulating hormone and can bind the TSH receptor, raising thyroid hormone needs in pregnancy.
- Every two-degree rise in scrotal temperature drops sperm count and viability by about 20%; heated car seats kill sperm.
- Alcohol carries seven kilocalories per gram and is GABAergic, suppressing LH/FSH and lowering testosterone.
- Topical caffeine works as a weak anti-androgen by crowding androgens out of the scalp's hair follicles.
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