Dimethandrolone undecanoate
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.[2][3][4] The medication has been found to profoundly and rapidly reversibly suppress testicular testosterone production in men when taken by mouth once per day for a month.[5][10] In addition to male contraception, there has also been interest in the potential use of DMAU in androgen replacement therapy for low testosterone levels in men.[18][19][14][8] Reduced sexual function and decreased bone mineral density have been observed with the closely related medication trestolone, which has low estrogenicity similarly to DMAU.[14][20][8] Unlike testosterone but similarly to 17α-alkyated AAS like methyltestosterone (17α-methyltestosterone), DMAU has been found to produce some effects indicative of potential liver toxicity when it was administered orally to animals.[15] A pharmacokinetic study of DMAU in men found that only 2 to 3% of the drug was hydrolyzed into dimethandrolone when it was administered orally in the form of powder in capsules.[3] Although the hydrolysis of DMAU into dimethandrolone was very limited, it was still sufficient to produce dose-dependent biological effects at the dosages assessed, including reversible suppression of luteinizing hormone and testosterone levels.