Pure Encapsulations NAC 600 mg 90 Capsules Vitacost NAC (N Acetyl Cysteine) Antioxidant Support for Glutathione Production 600 MG (120 Capsules) by Megafood at the Vitamin Shoppe NAC has direct antioxidant properties on oxidant species (e.g. OH ) Download Scientific Diagram As I mention in my book, N acetyl cysteine (NAC) is not found in food sources, but in the body, it converts into cysteine. NAC acts as a precursor to glutathione, a powerful N Acetyl L Cysteine, NAC Easily absorbed Life Extension Europe Natural Factors N Acetyl L Cysteine 600 mg, 60 Capsules Highland Health Foods