The acronym for S-Adenosyl-L-Methionine. It is naturally made in the body from a reaction between methionine, an essential amino acid, and another molecule that carries energy. It is involved in many different reactions in the body. Available as a dietary supplement in the U.S. since 1999, it has been used as a prescription drug in some countries of Europe since the 1980s. It is primarily taken for osteoarthritis and depression and may also positively benefit a variety of other conditions including psychiatric illnesses, infertility, liver problems, premenstrual disorders, and musculoskeletal conditions.