dutasteride [ 17beta-N-(2,5-bis(trifluoromethyl))phenyl-carbamoyl-4-aza-5alpha-androst-1-en-3-one,Avodart,GG 745,GG-745,GG745,GI198745,GlaxoSmithKline brand of dutasteride ] inhibits both type I and type II of 5-alpha-reductase; structure given in first source