What did @trichogenics actually say?
The video makes three core arguments: TRT raises testosterone, raised testosterone raises DHT, and elevated DHT accelerates hair loss in genetically predisposed men. The creator then concludes that "most likely you'll need to be on a 5 alpha reductase inhibitor like finasteride or dutasteride" if you're on testosterone. That's a fairly clean mechanistic claim, and it's worth pulling apart each link in that chain.
To be clear, this isn't fringe thinking. The testosterone-to-DHT pathway is well-established biochemistry. But the leap from "TRT raises DHT" to "everyone on TRT probably needs a 5-alpha reductase inhibitor" is where the nuance gets lost.
Does the science back this up?
Mostly, yes, but with important caveats. The androgen sensitivity model of androgenetic alopecia is strongly supported. DHT binds to androgen receptors in genetically sensitive hair follicles, shortening the anagen phase and miniaturizing the follicle over time. Randall (2008, Journal of Endocrinology) and Sinclair (1998, New England Journal of Medicine) both confirm this mechanism. Finasteride's efficacy is also well-documented: the original pivotal trials by Kaufman et al. (1998, Journal of the American Academy of Dermatology) showed statistically significant hair count improvement versus placebo.
Where the video oversimplifies is the assumption that exogenous testosterone reliably and uniformly raises DHT to clinically meaningful levels in all men. DHT elevation depends on the testosterone ester used, the dose, the delivery method, and individual 5-alpha reductase enzyme activity. Transdermal testosterone, for example, tends to raise DHT more than intramuscular injections, partly because skin is rich in 5-alpha reductase. That distinction is never mentioned.
What did they get wrong (or right)?
They got the core mechanism right. Testosterone does convert to DHT via 5-alpha reductase, and if you have androgenetic alopecia in your family history, supraphysiologic or even high-normal testosterone levels can accelerate shedding. Credit where it's due.
What they got wrong is the blanket prescription: "most likely you'll need to be on a 5 alpha reductase inhibitor." That phrasing implies universal necessity, which isn't supported. Men without genetic predisposition may see little to no hair impact. Men on physiologic-range TRT with low baseline DHT may not need pharmacological intervention at all. And the video says nothing about monitoring DHT levels through bloodwork, which is the rational first step before adding another medication.
There's also no mention of side effects associated with finasteride and dutasteride, including post-finasteride syndrome (though contested, it is documented in the literature, see Traish et al., 2015, Sexual Medicine Reviews), sexual dysfunction, and mood changes. Recommending these drugs casually to "most" TRT users without that context is incomplete at best.
What should you actually know?
If you're on TRT and worried about hair loss, get your DHT levels tested before assuming you need a 5-alpha reductase inhibitor. Genetic predisposition matters enormously, and not every man on TRT will experience accelerated shedding. The delivery method of your testosterone also matters: topical formulations are more likely to raise DHT than injected forms.
Finasteride and dutasteride are legitimate tools with real evidence behind them, but they are not risk-free. Dutasteride blocks both type 1 and type 2 5-alpha reductase, making it more potent than finasteride but also carrying a broader systemic effect on androgens. Neither should be started reflexively. A conversation with a physician who looks at your full hormone panel, family history, and current scalp status is the appropriate path.
- DHT elevation on TRT varies significantly by delivery method and individual enzyme activity.
- Finasteride and dutasteride carry documented side effect profiles that deserve disclosure.
- Not every TRT user is a candidate for 5-alpha reductase inhibition, and bloodwork should guide that decision.