Glutathione, also known as GSH, is a molecule found naturally in your body. Produced by the liver, glutathione is made up of three amino acids: L-cysteine, glycine, and L-glutamate. Glutathione is thought to offer antioxidant effects, as well as stimulate the immune system. Glutathione is a tripeptide (L-glutamic acid, L-cysteine, and Glycine) that is known as the most prominent nonenzymatic antioxidant in the human body, and is a substrate of a regulatory system of enzymes involved in regulating glutathione metabolism. Maintaining optimal levels of glutathione is essential to your health, according to a 2004 report published in the Journal of Nutrition. The report's authors note that glutathione plays a key role in antioxidant defense, breakdown of nutrients, and regulation of many biological processes (including immune response)