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 Glutathione, NAC & Vitamin C 30 Veg caps Glutathione, NAC & Vitamin C N Acetyl L Cysteine, NAC Easily absorbed Life Extension Europe NAC N Acetyl Cysteine + Glutathione 120 Capsules 2028mg Antioxidant Supplement 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