SAM-e Benefits Enhances Mood and Neural Function Promotes Joint Comfort and Mobility Supports Liver Health and Detoxification Best SAM-e 400 contains 400 mg of active SAM-e in each tablet. Doctors Best utilizes only the highest quality Italian SAM-e available on the market. This ensures the most potent SAM-e product with the highest percentage of the active S,S form per serving. S-Adenosyl Methionine SAM-e is derived from the amino acid methionine and is one of the most important methyl donors in the central nervous system. Methylation donation of methyl groups is an essential process in ensuring the proper function of a number of organ systems. Methylation occurs billions of times daily in the many organs of the body. 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