Acetylcysteine Antioxidant & Mucolytic Agent APExBIO 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 (N Acetyl Cysteine) with Reduced Glutathione, 240 Capsu Deal Supplement Exploring the Evidence of N Acetyl Cysteine (NAC) for Mood Disorders Psychopharmacology Institute Existing and potential therapeutic uses for N acetylcysteine: The need for conversion to intracellular glutathione for antioxidant benefits ScienceDirect