Methyldienolone (developmental code name RU-3467), also known as 17ñ-methyl-19-nor-ô<sup>9</sup>-testosterone, as well as 17ñ-methylestra-4,9-dien-17ò-ol-3-one, is a synthetic, orally active anabolic-androgenic steroid (AAS) and a 17ñ-alkylated derivative of 19-nortestosterone. It is closely related to dienolone and ethyldienolone.
Methyldienolone is on the World Anti-Doping Agency's list of prohibited substances, and is therefore banned from use in most major sports.