Glutathione: The Master Antioxidant Glutathione is often called the body's "master antioxidant" and for good reason. This powerful tripeptide (made from cysteine, glycine, and glutamate) is produced naturally in your cells, Tripeptide an overview ScienceDirect Topics Glutathione, a tripeptide found in virtually all cells, functions as a reducing agent. The structure of glutathione is: What amino acids make up glutathione? Homework.Study.com Glutathione Single Peptide RegenMD