(pharmacology) A nitrogenous steroid derivative C₂₃H₃₆N₂O₂ that inhibits the conversion of testosterone to the more potent dihydrotesterone in the human prostate gland and hair follicles, used in the treatment of benign prostatic hyperplasia and male pattern baldness.

(medicine, pathology) A cluster of symptoms characterized by sexual, neurological, hormonaland psychological side effects that persist in males who have taken finasteride.