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 NAC (N Acetyl Cysteine) Antioxidant Support for Glutathione Production 600 MG (120 Capsules) by Megafood at the Vitamin Shoppe Amazon.com: DEAL SUPPLEMENT NAC Supplement (N Acetyl Cysteine) 1,000mg Per Serving with Reduced Glutathione, 240 Capsules Antioxidant Support for Immune Health, Lung, & Liver Function : Health & Household NAC Supplement N Acetyl Cysteine 600mg per Serving Vegan High Absorption Non Smelly NAC Capsules Glutathione for Liver Support plus Lung Health and