Ademetionine is a naturally occurring amino acid present in virtually all body tissues and fluids. Ademetionine functions primarily as a co-enzyme and donor transfer of the methyl group (transmethylation) is an essential metabolic process in humans and animals. Ademetionine is also a precursor in the formation of physiological sulfurated compounds (cysteine, taurine, glutathione, CoA, etc.) via transsulfuration. It is used for the treatment of intrahepatic cholestasis.