SAM-e is involved in numerous biochemical reactions in tissues including the liver, joints and brain. SAM-e is also required for the biosynthesis of critical neurotransmitters and hormones. SAM-e is the methyl donor that catalyzes the production of epinephrine, melatonin, glutathione and the amino acids cysteine and taurine. SAM-e is also known to upregulate the production of critical membrane phospholipids including phosphatidylcholine. SAM-e is also a sulfur donor and, for this reason, is critical for the formation of sulfur-containing proteoglycans in joint connective tissue.