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 is such an important antioxidant in human physiology, meaning it acts to combat oxidative stress. Strategies for increasing glutathione include: Consume sulfur rich foods like cruciferous vegetables Ensure you get Role of Glutathione in Food and Human Diseases Encyclopedia MDPI The 7 Best Glutathione Foods Foods Highest in Glutathione Which foods are highest in glutathione ?