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 Amazon.com: Pure Encapsulations Liposomal Glutathione Immune Support & Liver Detox* Antioxidant Protection with Setria Glutathione Non GMO 60 Softgel Capsules : Health & Household Amazon.com: 2 Pack NAC Supplement (N Acetyl Cysteine) 1,000mg Serving with Reduced Glutathione, 480 Capsules : Health & Household Glutathione Amino Acids: Why Supplements May Not Work The Transulphuration Pathway Lifecode Gx Support Frontiers The versatile utility of cysteine as a target for cancer treatment