Finasteride

Finasteride is a 5-alpha reductase inhibitor that blocks the enzyme responsible for converting testosterone into dihydrotestosterone (DHT), the more potent androgen primarily responsible for hair follicle miniaturization and excess hair growth. In women with PCOS, finasteride can be effective for treating both androgenetic alopecia (hair thinning) and hirsutism (excess body hair) by reducing DHT levels at the tissue level. Like spironolactone, finasteride carries teratogenic risks and must be used with reliable contraception, and is typically reserved for cases where other anti-androgen treatments have been insufficient.