Could Bicalutamide Help Trans Women Regrow Hair Lost to Testosterone?

Bicalutamide is a prescription-only medication developed to treat prostate cancer, not hair loss. Using it for hair regrowth is "off-label" — outside its approved purpose. Its antiandrogen action has made it a candidate people discuss for androgen-driven hair loss, but no clinical study has evaluated it for hair regrowth in trans women. Anything said about its benefits for this group is inference, not evidence. Bicalutamide belongs to a class of medications known as non-steroidal antiandrogens. Unlike drugs that reduce testosterone production, it does not lower testosterone or dihydrotestosterone (DHT) levels in the blood. Instead, it blocks these hormones from binding to androgen receptors throughout the body, including in the scalp. That mechanism matters because androgen activity at the follicle is one of the main drivers of pattern hair thinning in people assigned male at birth.

The U.S. Food and Drug Administration approved bicalutamide in 1995 for advanced prostate cancer. It was never intended or tested as a treatment for alopecia, and it is not approved for that use anywhere. Its application to hair loss is experimental and belongs under a prescriber's supervision.

What the Research Shows

No study has examined bicalutamide's effect on hair in trans women. What exists is research in cisgender women with female pattern hair loss (FPHL). Those findings cannot be assumed to transfer to a different population, a different hormonal context or a different pattern of loss.

The one randomized controlled trial of bicalutamide for hair loss reported a negative result. Published in 2025 in JAAD International by a Brazilian group, it enrolled 74 women with FPHL and randomized them to bicalutamide 25 mg/day plus oral minoxidil 1 mg/day, or to placebo plus oral minoxidil 1 mg/day, for 24 weeks. (Minoxidil at 1 mg/day is the low-dose oral form, not the topical solution.) Hair density rose in both arms — a mean increase of 18.1 hairs/cm² in the bicalutamide group against 21.5 hairs/cm² in the minoxidil-only group, a difference that was not statistically significant (P = .86) — and blinded assessment of clinical photographs found no difference either (P = .78). The authors concluded that adding bicalutamide 25 mg/day provided no additional improvement over minoxidil alone. The trial was single-centre with 24 weeks of follow-up, and its participants were cisgender women.

A 2024 retrospective study in the Australasian Journal of Dermatology compared bicalutamide 50 mg/day with spironolactone 100 mg/day in 120 women aged 18–50 with FPHL, all of whom also used topical minoxidil 2%. At 24 weeks, the reduction in hair-loss severity on the Sinclair scale was greater in the bicalutamide group (28.20%) than the spironolactone group (19.51%), a difference the authors report as statistically significant; on global photographic assessment the difference did not reach significance (P = .139). The authors themselves note the study is limited by its retrospective design and small sample, which means selection bias cannot be excluded — this is a comparison of two off-label antiandrogens, not evidence that either works against no treatment.

Bicalutamide has also been injected into the scalp (mesotherapy) in very small case series, reported in the Indian Journal of Dermatology, Venereology and Leprology and elsewhere. In the series described here, four women were treated and only one showed notable regrowth at 24 weeks, while two were unchanged and one worsened. With numbers that small and no control group, nothing can be concluded from them either way.

On safety, the 2020 retrospective review of 316 women taking oral bicalutamide for FPHL, published in the Journal of the American Academy of Dermatology, examined tolerability rather than regrowth. Liver enzyme elevations were reported in a small number of patients and were described as resolving. That is short-term data from a specialist clinic where liver function was being monitored — it is a reason to monitor, not a reason to assume the drug is safe unmonitored. Bicalutamide's labelling carries a hepatotoxicity warning, including rare severe liver injury.

User Experiences: Can Bicalutamide Help Trans Women Regrow Hair Lost to Testosterone?

Bicalutamide is discussed in the trans community as a possible way to recover androgenic hair loss from testosterone exposure before transition. On Tressless, several transgender women have shared experiences with it, often comparing it with spironolactone. The following is a synthesis of those community discussions, which are individual accounts rather than measured outcomes.

A thread titled "Insane MTF recovery 18 months blocking androgens" features a transgender woman reporting substantial regrowth after 18 months of estrogen therapy and antiandrogen use that included bicalutamide. Her regimen also included dutasteride and RU58841, so nothing in that account can be attributed to bicalutamide specifically. RU58841 is an unapproved research chemical that has never completed human trials and is not available as a medicine. Feminizing hormone therapy on its own changes the hormonal environment at the follicle substantially, which is a further reason a single case with several simultaneous changes cannot show what any one of them did.

In another discussion, users compared bicalutamide with spironolactone for androgenic alopecia in women and described different side-effect profiles. Community users report preferring bicalutamide for the absence of spironolactone's anti-mineralocorticoid effects, such as increased urination and potassium changes; the same threads repeatedly raise liver-enzyme monitoring because of oral bicalutamide's hepatic risk.

What We Still Don't Know About Trans Women

Bicalutamide is prescribed by some clinicians as part of feminizing hormone therapy for its antiandrogen effect, where it may reduce testosterone-related features such as facial hair or acne. There are no published clinical trials evaluating whether it helps trans women regrow scalp hair lost to testosterone. Anecdotal accounts are not a substitute for that evidence.

A 2021 systematic review in Dermatologic Therapy (Heidelberg) examined dermatologic care of hair in transgender patients. Its authors describe a paucity of literature to guide dermatologists in this area, and set out treatment options partly on the basis of their own clinical experience because the published evidence is thin. Without clinical data in this population, whether bicalutamide would help a trans woman with androgenic hair loss is unknown.

Evaluating the Evidence — Strengths and Gaps

The strongest study available — the only randomized trial — found that bicalutamide added nothing to minoxidil in cisgender women. The retrospective comparison against spironolactone is more favourable but is retrospective, and the mesotherapy series are too small to interpret. None of this research includes trans women, none of it demonstrates regrowth of the kind the community anecdotes describe, and the use remains unapproved and off-label.

Bicalutamide also carries real risk, principally liver injury, which is why prescribers monitor liver function before and during treatment. Talk to a doctor or pharmacist before starting, stopping or combining bicalutamide, particularly alongside hormone therapy. For readers who could become pregnant, bicalutamide is contraindicated in pregnancy and can harm a developing fetus; tablets should not be crushed, split or handled by anyone who is or may become pregnant.

Final Thoughts: Proceed With Caution

Bicalutamide is a prescription medication approved for prostate cancer, and its ability to block androgens at the receptor is why it is discussed for hair loss. The published evidence in cisgender women is mixed and includes one randomized trial that showed no added benefit; no evidence at all addresses whether it helps trans women regrow hair lost to testosterone.

For now the answer to the question in the title is that nobody knows, and the best available trial gives no reason for optimism about bicalutamide as an add-on. Anyone considering it for hair-related reasons should do so with a prescriber who will monitor them, and with realistic expectations.

References

Libório, R. D. S., Motta, A. V. D., Miot, H. A., & Müller Ramos, P. (2025). Bicalutamide 25 mg combined with minoxidil 1 mg versus minoxidil 1 mg for female pattern hair loss: A randomized double-blind clinical trial. JAAD International, 19, 48–55. PMID 40034971. https://doi.org/10.1016/j.jdin.2024.12.002

Jha, A. K., Zeeshan, M. D., Singh, A., & Singh, A. K. (2024). Efficacy and safety of spironolactone versus bicalutamide in female pattern hair loss: A retrospective comparative study. Australasian Journal of Dermatology, 65(5), 437–443. PMID 38762801. https://doi.org/10.1111/ajd.14306

Carvalho, R. M., de Brito, F. X., & Ramos, P. M. (2024). Mesotherapy with bicalutamide for female pattern hair loss. Indian Journal of Dermatology, Venereology and Leprology, 1–3. PMID 39361861.

Ismail, F. F., Meah, N., Trindade de Carvalho, L., Bhoyrul, B., Wall, D., & Sinclair, R. (2020). Safety of oral bicalutamide in female pattern hair loss: A retrospective review of 316 patients. Journal of the American Academy of Dermatology, 83(5), 1478–1479. PMID 32213304. https://doi.org/10.1016/j.jaad.2020.03.034

Motosko, C. C., & Tosti, A. (2021). Dermatologic care of hair in transgender patients: A systematic review of literature. Dermatology and Therapy (Heidelberg), 11(5), 1457–1468. PMID 34235628. https://doi.org/10.1007/s13555-021-00574-0

Reddit user. (2023, April 27). Insane MTF recovery 18 months blocking androgens. r/tressless. https://reddit.com/r/tressless/comments/1313o71/insane_mtf_recovery_18_months_blocking_androgens/

Reddit user. (2022, April 25). Spironolactone vs bicalutamide: What is the difference between them for androgenic alopecia for women? r/tressless. https://reddit.com/r/tressless/comments/ub8wre/spironolactone_vs_bicalutamide_what_is_the/

Reddit user. (2022, October 12). How effective is spironolactone? r/tressless. https://reddit.com/r/tressless/comments/y2inbi/how_effective_is_spironolactone/