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, What is glutathione and why must we protect patient access to it? Glutathione: Master Antioxidant, Reducing Oxidative Stress, and Detoxification Reduced Glutathione Complex Orange Swanson Vitamins