NAC + Glycine NOVELTY! - A unique combination of N-acetylcysteineand L-glycine NAC (N-acetylcysteine) + glycine amino acids in an optimal ratio. N-acetylcysteine540 mg L-Glycine 2160 mg No fillers The best absorption is achieved by taking on an empty stomach. NAC and Glutathione NAC (N-acetylcysteine) is one form of the amino acid cysteine. In nature, NAC is found in onions, but the straight cysteineamino acid (which does the same thing) is found most abundantly in, for example, eggs and meat, and to a lesser extent in broccoli, onions and whole grain products. The most important function of the amino acid cysteinein the body is to act as a raw material for the production of the body's strongest antioxidant - glutathione. Our body needs three amino acids (cysteine, glycine and glutamine) to form glutathione. A particularly large amount of glutathione is found in the surface cells of the respiratory tract.