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 Supplement for Glutathione Boost and Liver Support The Yack on NAC (N Acetyl Cysteine) and Parkinson's Journey with Parkinson's GLUTATHIONE INJECTION GLUTA KOJIC WHITE ILLUMINATEUR WHITENING MILK (400ML) Blessed Prinx Cosmetics Extreme Glutathione Injection Lotion And Soap NAC (N Acetyl Cysteine) Antioxidant Support for Glutathione Production 600 MG (120 Capsules) by Megafood at the Vitamin Shoppe