Measurement of Glutathione as a Tool for Oxidative Stress Studies by High Performance Liquid Chromatography Making bloodwork work: the impact of sample collection, processing, and storage on plasma glutathione measurement, and implications for translation Translational Psychiatry 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, Measurement of Glutathione as a Tool for Oxidative Stress Studies by High Performance Liquid Chromatography