S-adenosylmethionine (SAM) is a naturally occurring compound found in all living cells. It plays a crucial role in the body's methylation processes, which are essential for the regulation of gene expression, protein function, and the metabolism of various molecules. SAM is synthesized from adenosine triphosphate (ATP) and methionine, an amino acid. In addition to its role in methylation, SAM is involved in the production of glutathione, a powerful antioxidant that helps protect cells from damage. SAM is also studied for its potential therapeutic effects in conditions like depression and liver disease, highlighting its importance in both health and disease management.