NAC vs Glutathione: Which Antioxidant Is Right for You? Momentous Glutathione vs. NAC: Why You Should Take NAC for Better Absorption Glutathione Vs NAC: Which is Best for Skin? 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 vs. Glutathione and How They Work Invigor Medical