Peter Attia MD291 ‒ Role of testosterone in men & women, performance-enhancing drugs, sustainable fat loss, & more
CHAPTERS
- 0:02 – 7:29
Testosterone, DHT and androgen receptor basics
Peter Attia and Derek set the agenda, then discuss how testosterone has been stigmatized and scheduled compared with estrogen and progesterone. Derek explains that testosterone and DHT act through the same androgen receptor in both sexes, differing mainly in amount, and that DHT drives maximal masculine differentiation.
- •Testosterone is scheduled and tightly regulated, unlike estrogen and progesterone
- •Both sexes make testosterone, estradiol and DHT, with men making roughly 10x more testosterone
- •DHT binds the androgen receptor with higher affinity and drives sexual differentiation
- •The androgen-to-estrogen ratio shapes how masculine or feminine characteristics develop
- 7:29 – 18:08
Androgenization risks and testosterone dosing in women
Peter shares a patient who took ten times her intended testosterone dose and developed clitoral enlargement that reversed. Derek describes how female bodybuilders choose less androgenic compounds, and both criticize clinics pushing cookie-cutter total testosterone targets of 200+ ng/dL for women, citing Derek's mother's experience.
- •A patient on a tenfold overdose for a month had reversible clitoral enlargement
- •Female bodybuilders favor oxandrolone or primobolan and monitor voice changes
- •Targets of 200–300 ng/dL in women exceed even peak physiologic levels
- •Acne can signal that a dose exceeds a woman's natural range
- •Prior oral contraceptive use skews baseline hormone levels and SHBG
- 18:08 – 22:08
Intranasal Natesto for on-demand libido
Peter asks whether intranasal Natesto could serve as an on-demand libido option for women instead of round-the-clock systemic testosterone. Derek reports a limited personal experience with a compounded version in a woman with low testosterone, with little effect, and notes tolerability complaints.
- •Natesto is dosed three times daily, implying low bioavailability
- •Peter wonders if women could use it on demand, like Cialis for ED
- •Derek's compounded-version experiment in one woman showed little libido effect
- •Women tend to dislike the sensation of using it
- •A clinical trial may be ongoing
- 22:08 – 28:37
DHEA supplementation in women versus men
Peter notes patients increasingly ask for DHEA, which is available over the counter in the US. Derek says it does nothing useful for testosterone in men, but in women a study showed 50 mg/day restored testosterone on combined oral contraceptives, likely because adrenal sources make up much of women's androgens.
- •DHEA is over-the-counter in the US but restricted in Canada
- •In men it shows no utility and may raise estrogen
- •In women on oral contraceptives, 50 mg/day restored total and free testosterone
- •Adrenal production explains the greater female sensitivity
- •Women with normal levels risk acne for little benefit
- 28:37 – 38:32
Progesterone's role beyond reproduction, in women and men
Peter explains that his practice now finds each woman's tolerable progesterone dose, backstopping with a Mirena if needed. Derek describes progesterone's calming metabolites, the effect of oral dosing, and his view that men might use it, with Peter questioning that.
- •Some women tolerate only 50–100 mg rather than a full 200 mg
- •Progesterone metabolites like allopregnanolone are anxiolytic and aid sleep
- •Oral dosing yields different metabolites than creams or injections
- •Progesterone is not approved for men; Derek uses 50–200 mg doses
- •It has negative feedback and possibly anti-androgenic effects
- 38:32 – 43:42
Free androgens, SHBG and testosterone lab measurement
Derek explains why men on TRT may be free-androgen dominant, given SHBG's binding of DHT and spiky injection patterns. The conversation moves to measuring free testosterone, comparing immunoassay and LC-MS results using Peter's own labs, and biotin interference.
- •SHBG binds DHT more strongly than testosterone, so lower SHBG can tilt toward free androgen dominance
- •Injection dosing creates spikes unlike natural pulsatile production
- •Equilibrium dialysis is the gold standard for free testosterone
- •Peter's immunoassay testosterone read 502 versus 381 on LC-MS, and estradiol 41.3 versus 18.3
- •Biotin can skew results and should be stopped before testing
- 43:42 – 54:07
Underground TRT sources and the Clomid/hCG trade-offs
They discuss rising interest in TRT among younger men, where men get it (Derek thinks mostly underground), and why Clomid and enclomiphene are likely not viable long-term. Peter expects regulation to push use toward Clomid and away from hCG.
- •Searches for TRT have skyrocketed over the past decade
- •Derek believes most men use underground rather than prescribed TRT
- •Long-term SERM use means estrogen receptor antagonism and unclear risks
- •Peter expects telemedicine rules to favor Clomid over hCG
- •hCG is fragile, refrigerated and costly
- 54:07 – 1:07:44
Diagnosing low testosterone: central versus testicular causes
Derek argues you should assess pituitary signaling and testicular function before starting TRT, and Peter walks through what an hCG response would imply for his own 381 total T. They discuss lifestyle and nutrient fixes, GnRH testing, pituitary workups, and recovery after prolonged suppression.
- •LH and FSH labs show whether the pituitary signal is adequate
- •hCG tests testicular response, while Clomid tests both pituitary and gonadal response
- •Sleep, calories, zinc, magnesium and vitamin D can move testosterone by 100+ ng/dL
- •Low estradiol could make Clomid fail as a test
- •Checking prolactin and ACTH can reveal pituitary problems
- •Most abusers recover within one to two years, though not always fully
- 1:07:44 – 1:20:00
FDA Category 2 peptide ruling and the hype around peptides
Peter and Derek discuss the FDA placing roughly 30 peptides, including BPC-157, CJC-1295 and others they covered, on a Category 2 list. They debate the gray-market response, the rationale, which compounds had utility, and the social-media quick-fix mentality.
- •Category 2 invites heavy scrutiny, but research chemical sites continue operating
- •The FDA's public rationale is safety and lack of approval
- •Derek considers some compounds useful, such as CJC-1295 and BPC-157, while tesamorelin remains approved
- •None of these peptides approaches testosterone's effect on lean mass and strength
- •Peter would like a trial of BPC-157 in postoperative orthopedic recovery
- 1:20:00 – 1:39:54
Follistatin gene therapy, myostatin and misleading before-and-after photos
Prompted by a social-media gene therapy claim, they review myostatin-knockout animals and the follistatin approach, including gray-market injections and the early human data. Derek explains how photos are manipulated, and Peter stresses skepticism about celebrity results.
- •Myostatin knockouts show a double-muscle phenotype, but the follistatin human trial showed about 2 lbs of lean mass gain
- •Mature mice with near-complete myostatin knockdown gained about 25% muscle
- •Lipid and metabolic markers trended the wrong direction in the trial
- •There is no validated follistatin assay
- •Lighting, pump, temperature, bloating and posture can fake dramatic transformations
- •Celebrity anecdotes ignore confounders like diet, exercise and steroids
- 1:39:54 – 1:48:31
Simple tricks for cutting calories and sourcing lean protein
Peter asks about appetite-suppression tricks from Derek's video. Derek recommends swaps like diet soda, leaner proteins, fat-free yogurt and egg whites, and Peter suggests hunting wild game as a budget-friendly lean meat source.
- •Diet soda can beat calorie-dense desserts in a deficit
- •Swapping to leaner proteins and egg whites can trim hundreds of calories
- •Peter favors wild game as lean red meat and describes hunting a cow elk
- •Bodybuilder tactics are the full toolbox, not an optimal healthy diet
- 1:48:31 – 2:05:11
Sustainable fat loss lessons from bodybuilders
Derek says bodybuilders cut in a staggered, tissue-preserving way, and outlines a framework with about 1 g/lb protein, tracked maintenance calories and a modest ~300-calorie deficit. They cover creatine, walking after meals for nutrient partitioning, and the dangers of cutting too fast.
- •Aim for roughly 1% of body weight per week at most, and about 1 g protein per pound
- •Find maintenance by eating a fixed diet for a week and watching the trend
- •A starting split of 40% protein, 40% carbs, 20% fat, with carbs adjusted for activity
- •Creatine is kept through the stage and is anti-catabolic
- •Walking after meals aids nutrient partitioning
- •Aggressive cuts cause earlier adaptation and reduced NEAT
- 2:05:11 – 2:12:37
Prolonged fasting and testosterone, plus high-protein ice cream
Peter wonders whether his repeated 7–10 day fasts lowered his testosterone, describing large drops in testosterone and thyroid shifts after fasts. Derek then pivots to the Ninja CREAMi for protein ice cream and why solid food satiates more than liquids.
- •Peter's fasts dropped total T from 500–600 to 100–200
- •Thyroid markers shifted, with free T3 falling and reverse T3 rising
- •Derek would like to see gonadotropin response after refeeding
- •The Ninja CREAMi turns frozen whey blends into ice-cream consistency
- •Solid or slushy foods are more satiating than drinks
- 2:12:37 – 2:23:57
Fat loss supplements: L-carnitine, caffeine and yohimbine
Peter asks about the fat-loss pharmacopeia. Derek covers injected L-carnitine and its mixed evidence, caffeine as a reliable and well-studied aid, and yohimbine as a racier, more situational option.
- •Injected carnitine avoids poor oral bioavailability and some TMAO concerns, but evidence is mixed
- •Home-brewed injectables are a bad idea, and compounding has had contamination problems
- •Caffeine is reliable, supports energy and training, and has safety data
- •Yohimbine is an alpha-2 antagonist that feels more aggressive than caffeine
- •Yohimbine is reserved for specific cases
- 2:23:57 – 2:31:16
Hypercortisolemia, anti-catabolic drugs and oxandrolone's status
Peter asks how to help an overnourished, undermuscled, metabolically unhealthy person with chronic stress and high cortisol. Derek notes yohimbine is a poor fit, says anabolics are the most potent anti-catabolic option, and explains oxandrolone losing its FDA approval.
- •Chronic hypercortisolemia drives lean tissue loss and fat gain
- •Ashwagandha and phosphatidylserine can help sleep
- •Oxandrolone antagonizes glucocorticoid receptors and is used in burn victims
- •FDA withdrew approvals of oxandrolone, with generics pulled
- •Oxandrolone is relatively less hepatotoxic among oral anabolics
- 2:31:16 – 2:48:55
Nutrition and training over drugs, and a critical eye on online influencers
Peter says body composition is mostly exercise, diet and testosterone, and Derek stresses anabolics don't work without diet, training and sleep, discussing the 600 mg testosterone study. They end by critiquing influencers such as Gary Brecka, Bryan Johnson and V Shred, and joke about getting a CREAMi.
- •Anabolics give a fraction of results without good training, diet and sleep
- •In the 600 mg study, even non-training testosterone users gained more lean mass than training placebo
- •Derek criticizes Gary Brecka's gene-testing claims, including that methylation converts T4 to T3
- •Peter says deiodinases, not MTHFR, convert T4 to T3
- •Bryan Johnson's many simultaneous interventions are hard to control for
- •V Shred's marketing is criticized as unethical
