S-Adenosyl-L-methionine disulfate tosylate is a methyl donor and cofactor. It is involved in a variety of biological processes, including epigenetic regulation, post-translational modification of proteins and metabolism. Preparations containing S-Adenosyl-L-methionine disulfate tosylate have been used as dietary supplements. S-Adenosyl-L-methionine disulfate tosylate also exhibits antiproliferative, pro-apoptotic and anti-metastatic effects in human cancers.