N-acetyl cysteine (NAC) is an acetylated form of the amino acid cysteine. Cysteine is part of the biochemical pathway to synthesize glutathione, an important antioxidant. N-Acetyl Cysteine from SuraVitasan provides 600 mg per capsule of NAC. Gluten free, Dairy free Animal origin: N-acetylcysteine (keratin hydrolysis of bird feathers) How to use: 1 capsule a day with food.