Methyldiazinol (also known as 3,3-azo-17ñ-methyl-5ñ-dihydrotestosterone, 3-azi-17ñ-methyl-DHT, or 3,3-azo-17ñ-methyl-5ñ-androstan-17ò-ol) is a synthetic and orally active androgen/anabolic steroid (AAS) which was never marketed. It is a 17ñ-methylated derivative of dihydrotestosterone (DHT); specifically, it is the C3 azi (i.e., 3,3-azo) analogue of mestanolone (17ñ-methyl-DHT). The drug has been found to possess a high ratio and dissociation of myotrophic to androgenic activity; relative to methyltestosterone, its ratio was 15 (3:0.2), among the highest observed.