Dimethandrolone undecanoate (DMAU), also known by its developmental code name CDB-4521, is an experimental androgen/anabolic steroid (AAS) and progestogen medication which is under development as a potential birth control pill for men. It is taken by mouth, but can also be given by injection into muscle. DMAU was first described in 2002. It was developed by the Contraceptive Development Branch of the National Institute of Child Health and Human Development, an agency in the United States government.