5α-Reductase Inhibitors: Finasteride and Dutasteride in Feminizing Therapy
July 2026
in “
Zenodo (CERN European Organization for Nuclear Research)
”
5α-reductase inhibitors finasteride dutasteride feminising hormone therapy testosterone dihydrotestosterone DHT androgen receptor androgenetic alopecia scalp androgenetic alopecia transfeminine individuals WPATH Standards of Care psychiatric effects sexual effects teratogenicity PSA suppression Propecia Avodart hair loss male pattern baldness transgender health
TLDR Finasteride and dutasteride have limited use in feminising therapy and are not recommended for routine use.
This review evaluates the use of 5α-reductase inhibitors, finasteride and dutasteride, in feminising hormone therapy, highlighting their limited role due to their mechanism of action, which only affects the conversion of testosterone to dihydrotestosterone (DHT) without suppressing testosterone production or antagonizing the androgen receptor. The review notes that these inhibitors do not significantly contribute to feminising effects beyond treating scalp androgenetic alopecia, as no controlled trials in transfeminine individuals have demonstrated a clear additive benefit. The World Professional Association for Transgender Health (WPATH) Standards of Care Version 8 advises against their routine use in feminising therapy. Additionally, the review discusses safety concerns, including psychiatric and sexual effects, teratogenicity, and PSA suppression, which have led to regulatory updates in Europe and the UK from 2024 to 2026.
