15 Glutathione Benefits: How to Improve Your Mind & Body N Acetyl Cysteine Functions as a Fast Acting Antioxidant by Triggering Intracellular H2S and Sulfane Sulfur Production: Cell Chemical Biology What is the recommended dosage of N acetylcysteine (NAC) for supporting glutathione levels? 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 N acetyl l cysteine averts ferroptosis by fostering glutathione peroxidase 4 ScienceDirect Glycine + N Acetyl Cysteine Supplementation Increases Lifespan