Why are some women using bicalutamide to fight hormonal hair loss?

Hormonal hair loss is a condition that affects millions of women worldwide, and for many, the emotional toll can be just as severe as the physical symptoms. In recent years, some women have asked their doctors about a medicine originally intended for prostate cancer in men: bicalutamide. Why is it discussed for hormonal hair loss, and what does the published research actually show?

Understanding the problem: What is hormonal hair loss in women?

Hormonal hair loss in women, often called female pattern hair loss (FPHL) or androgenetic alopecia, is a progressive condition that results in the gradual thinning of hair. Unlike men, who typically lose hair in distinct patterns such as receding temples or bald spots on the crown, women usually experience a diffuse reduction in hair density. This means the scalp becomes more visible, especially in the parting area, while the frontal hairline is generally preserved. For many women, this type of hair loss can feel like a profound and often silent trauma. Hair has strong ties to identity, femininity, and self-esteem. As a result, losing hair does not only change one’s appearance; it can deeply impact emotional well-being. Feelings of embarrassment, social withdrawal, anxiety, and even depression are common. Despite this, hair loss in women is often misunderstood or dismissed as a cosmetic issue, which can intensify the psychological burden.

The underlying cause of this condition is usually linked to androgens — hormones like testosterone that are present in both men and women. When there’s an imbalance, either due to genetic predisposition, menopause, or hormonal disorders like polycystic ovary syndrome (PCOS), hair follicles may become overly sensitive to these hormones. The most potent form of testosterone in this context is dihydrotestosterone (DHT), which binds to receptors in scalp hair follicles and causes them to shrink. This process is known as follicular miniaturization. Over time, the hairs become finer, grow more slowly, and eventually stop growing.

Bicalutamide: what it is

Bicalutamide is a non-steroidal anti-androgen approved by the FDA in 1995 for treating prostate cancer in men. It works by binding to androgen receptors, preventing testosterone and DHT from activating them. Unlike drugs like finasteride, which reduce DHT production by targeting an enzyme, bicalutamide blocks the action of androgens at the receptor site — essentially occupying the "lock" that androgens would otherwise "open." That mechanism is the reason some prescribers consider it for androgen-related hair loss. Whether it translates into better hair in women has not been shown in a controlled trial.

How is bicalutamide being used for hair loss?

Bicalutamide is not approved for hair loss anywhere. Its US prescribing information goes further: it lists women under its contraindications, stating that the drug "has no indication for women, and should not be used in this population." Some dermatologists and endocrinologists nevertheless prescribe it off-label, against that labelling, mostly for women who have not responded to, or cannot take, other treatments. The two comparative studies described below used 25 mg or 50 mg a day; the prostate-cancer label dose is 50 mg a day. Prescribers who use it order liver blood tests, because liver injury is the drug's main known risk (see below).

Does the science support this off-label use?

The evidence is limited, and the one randomised trial was negative.

• Randomised trial (2025). A double-blind trial published in JAAD International enrolled 74 women with female pattern hair loss. They took bicalutamide 25 mg/day or placebo, each alongside oral minoxidil 1 mg/day, for 24 weeks. Hair density rose in both groups (18.1 versus 21.5 hairs/cm², P = .86). The authors concluded that adding bicalutamide gave no additional improvement. The trial was single-centre and short.
• Retrospective safety review (2020). A review of the medical records of 316 women treated with oral bicalutamide in a specialist clinic, published in the Journal of the American Academy of Dermatology, looked at tolerability rather than regrowth. It has no control group.
• Pilot study (2019). A small uncontrolled pilot study of oral bicalutamide in female pattern hair loss was published in Dermatologic Therapy.
• Retrospective comparison (2024). A retrospective study of 120 women in the Australasian Journal of Dermatology compared bicalutamide 50 mg/day with spironolactone 100 mg/day, both with topical minoxidil. It reported a greater reduction in a hair-loss severity score with bicalutamide; its authors note that the retrospective design and small sample limit it.

No study has shown long-term outcomes.

User Experiences

Bicalutamide is discussed among women in the Tressless community who are dealing with hormonal hair loss. Many users report turning to it after other anti-androgens like spironolactone did not help or caused unwanted side effects. Several women describe it as more tolerable for them than spironolactone; for example, some note that spironolactone led to frequent urination, which they did not experience with bicalutamide. One user said she preferred bicalutamide because she did not have the menstrual irregularities she had on spironolactone. Another said she had no mood changes on it. These are individual accounts, not trial results.

Other users raise concerns about bicalutamide’s effects on the whole body. A woman considering the treatment worried about loss of muscle mass, given the drug’s anti-androgenic activity. In the same discussion, dutasteride and RU58841 were mentioned as alternatives. RU58841 is an unapproved research chemical that has never completed human trials and is not a medicine. Dutasteride is not approved for hair loss in women in any country. Dutasteride and bicalutamide can both harm a developing fetus, and neither should be used by anyone who is or may become pregnant.

One obstacle many women mention is the difficulty of obtaining a prescription. Because of the drug's labelling and liver risk, some dermatologists decline to prescribe it. A user explained that her new doctor would not provide bicalutamide or dutasteride off-label, despite her past use. She eventually found another practitioner who would, which shows how access depends on the individual prescriber and local rules.

Among the more complex cases, users with aggressive androgenic alopecia report combining bicalutamide with other treatments such as minoxidil, birth control pills and steroid injections. One user reported that her best short-term result came from steroid injections. Another described visible improvement within ten weeks on a combination of bicalutamide, minoxidil and estradiol; with several changes at once, no single drug can be credited. Combining prescription anti-androgens is a decision for a prescriber.

Why bicalutamide and not other anti-androgens?

Other anti-androgens such as spironolactone and cyproterone acetate have long been used off-label or on-label in female dermatology, depending on the country. They have their own side effects. Spironolactone can cause irregular periods, breast tenderness, dizziness and changes in potassium levels. Cyproterone acetate has been linked to meningioma (a usually benign brain tumour), particularly with long use at high doses. Bicalutamide has no diuretic or progestogenic action, which is why some users and prescribers consider it. No randomised trial has compared bicalutamide's side effects with those of spironolactone or cyproterone.

The liver concern: How serious is it?

The US label warns that severe liver injury, including deaths from liver failure, has been reported, usually in the first three to four months of treatment. In the prostate-cancer trials, hepatitis or marked rises in liver enzymes that led to stopping the drug occurred in about 1% of patients. The label asks for liver blood tests before starting, at regular intervals for the first four months, and periodically after that. The label dose is 50 mg a day, and no study has shown that the 25–50 mg doses used for hair loss avoid this risk. The label also lists breast pain, hot flushes, sensitivity to sunlight, and rare lung inflammation (interstitial lung disease), and it warns that bicalutamide can increase the effect of warfarin-type blood thinners. Anyone taking it should report yellowing of the skin or eyes, dark urine, persistent nausea or pain in the upper right abdomen to a doctor straight away.

Pregnancy

Bicalutamide is contraindicated in pregnancy and can harm a developing male fetus. Anyone who could become pregnant needs reliable contraception, agreed with the prescriber, and should not take it while pregnant or trying to conceive. Ask a pharmacist before splitting or crushing tablets, and keep broken tablets away from anyone who is or may become pregnant.

Summary

Bicalutamide blocks androgens at the receptor rather than changing hormone production, which is why it is discussed for androgen-related hair loss in women. The published evidence is limited: retrospective case series, a small pilot study, and one randomised trial that found no added benefit over oral minoxidil. Its US label says it should not be used in women, warns of severe and fatal liver injury, and contraindicates it in pregnancy. Talk to a doctor before starting, stopping or combining bicalutamide; anyone who uses it off-label needs a prescriber who monitors liver function.

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

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

Fernandez-Nieto, D., et al. (2019). Oral bicalutamide for female pattern hair loss: A pilot study. Dermatologic Therapy, 32(6), e13096. PMID 31579984. https://doi.org/10.1111/dth.13096

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

U.S. National Library of Medicine, DailyMed. CASODEX (bicalutamide) tablets, prescribing information. https://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=dfee4fe7-8478-4a3e-925d-00be3cd0ab67

U.S. National Library of Medicine, DailyMed. AVODART (dutasteride) capsules, prescribing information. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=960797b3-09b1-4d6a-8ece-8b5d918e93e4