Determination of Sulfur Amino Acids, Glutathione, and Related Aminothiols in Biological Samples by Gas Chromatography with Flame Photometric Detection Springer Nature Link Frontiers Glutathione: A Samsonian life sustaining small molecule that protects against oxidative stress, ageing and damaging inflammation 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: Master Antioxidant, Reducing Oxidative Stress, and Detoxification