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 Health or NAD? Here's Why You Probably Need Both: Envizion Medical: Wellness Center NAC vs Glutathione: Which Antioxidant Is Right for You? Momentous All About NAC (N acetylcysteine): What it is and what benefits it has Zenement