Glutathione is a tripeptide made from the amino acids glutamic acid, cysteine and glycine. The word tripeptide means that it is built from three amino acids. Glutathione has a long list of uses and effects in the human body. It is an important antioxidant. It supports immunity, is involved in tissue repair, and is a building block for many other chemicals produced in the body. It also contains sulfur, which can bind to heavy metals to help excrete them from the body.