With 400 mg Active S-Adenosyl Methionine Per Tablet. Pharmaceutical Grade. Enhances Mood & Neural Function. Promotes Joint Comfort & Mobility. Supports Liver Health & Detoxification. Doctor's Best Double-Strength SAMe 400 contains 400 mg of active SAMe in each tablet. Doctor's Best utilizes only the highest quality Italian SAMe available on the market. This ensures that you receive the most potent SAMe product with the highest percentage of the active S,S form per serving, bar none. S-Adenosyl Methionine (SAMe) 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. SAMe is involved in numerous biochemical reactions in tissues including the liver, joints and brain. SAMe is also required for the biosynthesis of critical neurotransmitters and hormones.