Extended release formulations of S-methyladenosylmethionine (SAMe) are provided, as are methods of treating various disorders using extended release SAMe formulations. The extended release formulations may be used to treat a variety of disorders, including liver disorders, psychiatric disorders and joint disorders. Thus, extended release SAMe formulations may be used to treat alcoholic liver disease, fatty liver disease, hepatitis, generalized anxiety disorder, obsessive compulsive disorder, post traumatic stress disorder, panic disorder, and depressive disorders such as depression (e.g. major clinical depression) and dysthymia.