TRT dosing mistakes: what doctors actually get wrong

What did @dr.randmcclain actually say?

McClain's argument is that doctors who dose testosterone based on a simple "make up the difference" math are making a physiological error. If you're at 400 ng/dL and your doctor wants you at 800, giving you just enough exogenous T to close that gap ignores the HPG axis. His claim: "your body is working on a thermostat" and the pituitary will simply reduce its own signaling, leaving you back at 400 or lower.

This is a specific, mechanistic claim about how the hypothalamic-pituitary-gonadal axis responds to exogenous testosterone administration. It's not vague wellness advice. It has a testable biological basis, and it's worth examining seriously rather than dismissing as influencer content.

Does the science back this up?

Largely, yes. The HPG axis suppression mechanism McClain describes is well-documented and not controversial in endocrinology. What he's describing is negative feedback: exogenous testosterone signals the hypothalamus and pituitary to reduce GnRH and LH secretion, which in turn suppresses endogenous testosterone production from the Leydig cells.

Bhasin et al. (2001, New England Journal of Medicine) demonstrated dose-dependent suppression of LH and endogenous testosterone when exogenous testosterone was administered to healthy men. The suppression wasn't partial or gentle. At doses typical of TRT, LH drops significantly. Shabsigh et al. (2005, Journal of Urology) similarly noted that men on TRT show measurable suppression of gonadotropins. The mechanism is not disputed. The clinical implication McClain draws, that underdosing leads to net-neutral or worse outcomes, follows logically from this physiology, though it's less directly studied as a standalone variable.

What did they get wrong (or right)?

He got the core biology right. The thermostat analogy is imprecise but not wrong. The HPG axis does operate through feedback loops that reduce endogenous production when circulating androgens rise, even modestly. Credit where it's due: this is a legitimate critique of naive dosing strategies that treat testosterone supplementation like adding water to a bucket.

What McClain glosses over is that this suppression is not always a problem requiring higher doses. The clinical goal of TRT is to reach a therapeutic level, not necessarily to preserve endogenous production. For men with primary hypogonadism, the testes aren't producing adequately regardless. For secondary hypogonadism, the suppression he describes is real but may still leave the patient at a clinically adequate total testosterone level if dosing is calibrated correctly over time. The claim that patients "drop back down to 400 or sometimes even less" is plausible but unsupported by a specific citation in his video, and the "or sometimes even less" framing leans toward alarm without hard data. Snyder et al. (2016, New England Journal of Medicine) showed that TRT can reliably raise testosterone levels when dosed appropriately, suggesting the suppression issue is manageable rather than inevitable.

What should you actually know?

The HPG axis suppression McClain describes is real physiology. Any doctor managing TRT should understand it. What this video doesn't tell you is that the clinical significance depends heavily on why you're on TRT in the first place, how your baseline LH and FSH looked, and what your treatment goals are.

If preserving fertility or endogenous function matters to you, there are co-administration strategies involving other medications that some clinicians use. That's a conversation between you and your prescribing physician, not a TikTok decision. The broader point, that dosing strategy matters and that a simplistic "fill the gap" approach can miss the mark, is valid. But "underdosing is a mistake" is not the same as "more is better," and McClain's framing risks pushing that implication without spelling out the risks of inappropriate dosing in the other direction.