Exploring the Evidence of N Acetyl Cysteine (NAC) for Mood Disorders Psychopharmacology Institute 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 vs. NAC: Why You Should Take NAC for Better Absorption Glutathione Vs NAC: Which is Best for Skin? NAC Health or NAD? Here's Why You Probably Need Both: Envizion Medical: Wellness Center