L Glutathione vs. Glutathione: What's the Difference? Invigor Medical NAC and Glutathione: The Amino Acid the Supplement Industry Is Not Telling You About Glutathione You Are The Healer Glutathione is the body's primary internal antioxidant, made using the amino acid cysteine, and it helps protect cells from oxidative stress. Beyond detoxification, research shows glutathione is involved in thyroid hormone metabolism, Glutathione CrackitToday Affairs