NAC is a dietary supplement in the form of convenient tablets that contains N-acetyl L-cysteine (NAC) – a modified form of cysteine, one of the endogenous sulfur amino acids. Meet NAC SFD 150 mg of N-acetylcysteine per serving. Up to 90 days of portioning. Tablet form – convenient for everyday use. N-acetyl L-cysteine is a modified form of cysteine attached to an acetyl group. Cysteine, in turn, is one of the endogenous amino acids, meaning the body can synthesize it itself. It is classified as a sulfur-containing amino acid—it contains sulfur in its side chain. Due to its specific structure, it is a highly reactive amino acid. The acetyl derivative of cysteine, NAC, is a precursor for the synthesis of glutathione, which is concentrated primarily in the liver. NAC Allnutrition ® capsules are an excellent choice for physically active individuals. They are especially useful after training.