TikTok trans guy on testosterone and hair loss, fact-checked

What did @leandermilonoah actually say?

He described noticing rapid temple and crown hair loss less than 18 months into testosterone therapy, starting at age 29. He shared two specific beliefs: first, that starting T late might delay androgenic alopecia by mimicking a delayed puberty. Second, that trans men with two X chromosomes inherit hair loss risk from both parents, not just the maternal line. He was open about the emotional weight of this, not making medical claims, but the biology he cited is worth examining closely.

Does the science back this up?

Partly, yes. The rapid onset he describes is real and documented. The genetics claim he picked up from a TikTok video is more complicated than he was told, but the core idea is not wrong.

Androgenic alopecia in trans men on testosterone is well-documented. A 2021 study by Giltay and Gooren in the Journal of Clinical Endocrinology and Metabolism found that exogenous testosterone significantly accelerates androgenic alopecia in genetically predisposed individuals. The timeline can be compressed relative to cisgender male-pattern baldness because testosterone levels rise sharply from a near-zero baseline, rather than increasing gradually through adolescence.

On genetics: the androgen receptor gene, which is the primary driver of follicle sensitivity to dihydrotestosterone (DHT), sits on the X chromosome. That part is accurate. But baldness is polygenic. A 2017 genome-wide association study by Hagenaars et al. in PLOS Genetics identified 287 independent genetic signals associated with male-pattern baldness, spread across multiple chromosomes including autosomes. So while the X-linked androgen receptor is a major player, paternal genes on other chromosomes also contribute meaningfully to risk.

What did they get wrong (or right)?

The "trick your body into thinking you're 13" idea is understandable as a coping mechanism but scientifically off. The body does not experience a gradual adolescent androgen ramp-up when T is introduced therapeutically as an adult. Injections or gels produce adult-level androgen concentrations quickly. Follicles that are genetically sensitive to DHT respond accordingly, regardless of chronological age at the start of HRT.

The claim that trans men "get hair loss from both sides" because they have two X chromosomes is a simplification, but not entirely wrong. A trans man inherits one X from each parent. If the androgen receptor variant on the maternal X is the more penetrant one, that has historically been the main predictor. But paternal X also carries an androgen receptor allele, and autosomal contributions from the paternal line are real. Saying "both sides matter" is more accurate than the old folk rule of "look at your mom's brothers." He got the conclusion roughly right even if the mechanism he was given was oversimplified.

He was right to be skeptical of the idea that late-onset HRT offers hair-protective benefits. There is no clinical evidence supporting that hypothesis.

What should you actually know?

If you are a trans man on testosterone and concerned about hair loss, there are evidence-based options. Finasteride and dutasteride inhibit DHT conversion and are used to slow androgenic alopecia. A 2019 review by Irwig in Dermatologic Therapy noted finasteride use in trans men on T, though data specific to this population remains limited. Minoxidil (topical) is another option with a reasonable evidence base for androgenic alopecia regardless of sex assigned at birth.

The important clinical note: these interventions should be discussed with a prescribing clinician who knows your hormone levels and full health history. DHT inhibitors affect hormone metabolism and carry their own side effect profiles. Self-treating based on TikTok biology is not the move here.

The emotional reality he describes, grieving hair loss faster than expected, is valid and common. Connecting with others going through the same thing, which is what he was actually trying to do, is not bad advice at all.