Dr. Kallonen's hormone therapy claims need more nuance

What did @breannekallonen actually say?

The claim is specific: women starting testosterone replacement therapy should have dihydrotestosterone (DHT) tested first, because some women already convert testosterone to DHT at high rates. If you give more testosterone to someone with elevated DHT, you "up-regulate the amount of DHT" and trigger hair loss, acne, and facial hair growth. She frames this as a preventable mistake that clinics are routinely making.

To her credit, she grounds this in an actual patient case with bloodwork, not just theory. The mechanism she describes, the enzyme 5-alpha reductase converting testosterone into DHT, is real pharmacology. The symptoms she lists, androgenic alopecia, acne, hirsutism, are textbook DHT-excess effects. This is not pseudoscience. Whether DHT testing should be a universal pre-TRT requirement for women is a different question, and that part is less settled than she implies.

Does the science back this up?

The core biology is solid. The clinical protocol recommendation is reasonable but not yet evidence-based as a standard of care. DHT is produced primarily through 5-alpha reductase activity, and individual variation in that enzyme's expression is well-documented. Women with higher 5-alpha reductase activity will convert more exogenous testosterone to DHT, amplifying androgenic side effects.

Glintborg et al. (2015, Journal of Clinical Endocrinology and Metabolism) confirmed that women with hyperandrogenism show elevated DHT correlating with androgenic symptom severity. Studies on female androgenic alopecia consistently implicate DHT sensitivity at the hair follicle level (Sinclair et al., 2015, International Journal of Dermatology). What is less clear is whether a single baseline DHT measurement reliably predicts who will have problems on TRT. DHT levels fluctuate, and the ratio of 5-alpha reductase activity to androgen receptor sensitivity matters too. The creator presents baseline DHT as a cleaner predictive tool than the current evidence fully supports.

What did they get wrong (or right)?

She got the mechanism right. DHT-mediated androgenic side effects from exogenous testosterone in women are real, documented, and genuinely underappreciated in some prescribing contexts. The observation that "many patients come to me with hair loss after utilizing testosterone replacement therapy" is consistent with reported adverse event patterns in the literature on off-label female testosterone use.

Where she oversimplifies: presenting DHT testing as the single missing check implies there is a clean cutoff, test high, don't treat, test normal, proceed. That is not how this works. Androgen receptor sensitivity varies independently of DHT levels. A woman with normal DHT but highly sensitive androgen receptors can still develop androgenic alopecia on TRT. Conversely, elevated baseline DHT does not automatically mean TRT is contraindicated. It means risk stratification and possibly co-prescribing a 5-alpha reductase inhibitor like finasteride, which she does not mention. The framing is useful but incomplete.

What should you actually know?

If you are a woman considering testosterone therapy, DHT is worth discussing with your provider, but it is one data point, not a go/no-go switch. Ask about your full androgen panel including free testosterone, SHBG, and DHEA-S. Ask whether your provider tracks side effects systematically over time, not just at baseline.

The broader issue she is circling is real: female TRT is largely off-label, guideline support is limited, and prescribing practices vary enormously. The Endocrine Society's 2019 guidelines on testosterone therapy in women were narrow in scope and did not endorse routine use for general wellbeing or libido in the absence of documented deficiency. That context matters when evaluating any clinic that offers testosterone to women with "normal" levels and symptom complaints alone.

• Hair loss from TRT in women is reported but not systematically tracked in most clinical settings.
• Finasteride and other 5-alpha reductase inhibitors can reduce DHT conversion but carry their own risk profiles.
• Baseline DHT testing is rational harm-reduction practice, even if it is not yet a formal standard of care.

Bottom line

@breannekallonen is raising a legitimate clinical concern in a way that is mostly accurate. The DHT mechanism is real. The oversight she describes happens. But the framing that one blood test prevents the problem is cleaner than reality allows. Hair loss risk on female TRT involves androgen receptor genetics, dosing, formulation, and individual metabolism, not just a single DHT number. Use this video as a starting point for a conversation with your provider, not a checklist.