Topterone (, ) (developmental code name WIN-17665), also known as 17ñ-propyltestosterone (or simply propyltestosterone) or as 17ñ-propylandrost-4-en-17ò-ol-3-one, is a steroidal antiandrogen that was first reported in 1978 and was developed for topical administration but, due to poor effectiveness, was never marketed.