Because hair thinning on endocrine therapy follows the pattern of androgenetic alopecia, the drugs used for that pattern are sometimes added. The evidence in cancer survivors cannot separate them from minoxidil, the one guideline that addresses spironolactone says not to use it routinely, and an expert panel advised against finasteride and dutasteride in breast cancer.
Endocrine therapy lowers oestrogen, which shifts the balance of signals at the follicle towards androgen effects, so the thinning it causes looks like female pattern hair loss. That reasoning is why spironolactone, an aldosterone antagonist with antiandrogen activity, and the 5-alpha-reductase inhibitors finasteride and dutasteride are sometimes prescribed to survivors. The reasoning is sound; the evidence is not there yet, and the guidance points the other way.
On efficacy, there is one number and it cannot be attributed. In the three-centre cohort of 192 women (JAMA Dermatology 2019), moderate to significant improvement after topical minoxidil or spironolactone was seen in 67 per cent of those with persistent chemotherapy alopecia and 76 per cent of those with endocrine-therapy alopecia; the two drugs are reported together and no part of that belongs to spironolactone alone. No randomised trial of any antiandrogen for cancer-related alopecia exists.
On safety, a systematic review of 47 studies (Rozner et al., Breast Cancer Research and Treatment 2019) found no evidence of interaction between 5-alpha-reductase inhibitors or spironolactone and the endocrine therapies used in breast cancer, and no consistent evidence of increased breast cancer risk with spironolactone across three studies covering 49,298 patients. It also found that oestrogen levels rose in a minority of women on each drug class, and that the risk of breast cancer with 5-alpha-reductase inhibitors has not been studied. Its conclusion was that spironolactone may be considered for further research, which is not the same as recommending it.
Two formal positions disagree with prescribing. The ESMO clinical practice guideline on dermatological toxicities states that spironolactone is not recommended because the risk and benefit analysis does not justify its routine use. A 2025 international Delphi consensus of fifteen experts on persistent chemotherapy-induced alopecia emphasised prevention by scalp cooling and early topical or low-dose oral minoxidil, and specifically did not recommend bicalutamide, oral finasteride or dutasteride for breast cancer patients, citing safety concerns. A dermatologist may still reach a different decision for an individual, and that is a conversation to have with the oncologist in the room.
Spironolactone blocks the androgen receptor and reduces androgen production; finasteride and dutasteride block the conversion of testosterone to dihydrotestosterone. Both reduce the androgen signal that miniaturises follicles in pattern hair loss.
Query for this technology: (TITLE:"Antiandrogens for hair: spironolactone, finasteride, dutasteride" OR ABSTRACT:"Antiandrogens for hair: spironolactone, finasteride, dutasteride") AND (cancer OR tumor OR tumour OR oncology OR carcinoma OR lymphoma OR leukemia OR leukaemia OR myeloma OR sarcoma OR melanoma OR glioma). Results are unfiltered search hits about Antiandrogens for hair: spironolactone, finasteride, dutasteride, not a curated reading list.
Shares Endocrine-therapy-induced alopecia, Persistent chemotherapy-induced alopecia, Minoxidil for persistent chemotherapy- and endocrine-therapy hair loss, Toxicity and quality of life are undervalued and the tags complementary, supportive-care, hair-loss.
Shares Endocrine-therapy-induced alopecia, Persistent chemotherapy-induced alopecia, Minoxidil for persistent chemotherapy- and endocrine-therapy hair loss, Toxicity and quality of life are undervalued and the tags complementary, supportive-care, hair-loss.
Shares Persistent chemotherapy-induced alopecia, Minoxidil for persistent chemotherapy- and endocrine-therapy hair loss, Toxicity and quality of life are undervalued and the tags complementary, supportive-care, hair-loss.
Shares Persistent chemotherapy-induced alopecia, Minoxidil for persistent chemotherapy- and endocrine-therapy hair loss, Toxicity and quality of life are undervalued and the tags complementary, supportive-care, hair-loss.
Shares Minoxidil for persistent chemotherapy- and endocrine-therapy hair loss, Toxicity and quality of life are undervalued and the tags complementary, supportive-care, hair-loss.
Shares Exemestane, Letrozole (and other aromatase inhibitors), Endocrine therapy (SERMs, AIs, SERDs), Toxicity and quality of life are undervalued and the tags complementary, supportive-care.
Shares Persistent chemotherapy-induced alopecia, Minoxidil for persistent chemotherapy- and endocrine-therapy hair loss, Toxicity and quality of life are undervalued and the tags complementary, supportive-care, hair-loss.
Shares Exemestane, Letrozole (and other aromatase inhibitors), Tamoxifen, Endocrine therapy (SERMs, AIs, SERDs) and the tags complementary, supportive-care.