What is Glutathione? Glutathione is a natural substance found in varying degrees in all cells, tissues, organ systems and fluids in the body. It is a tripeptide compound, made up of three amino acids: cysteine, glycine and glutamic acid. Glutathione is best known for its role as a powerful antioxidant. The body naturally produces glutathione, but levels are known to decrease with age. Factors such as poor diet, strenuous exercise, being overweight and certain health conditions can also affect glutathione levels.  Glutathione can be obtained through diet, with meat being an ideal source, and fruits and vegetables (such as spinach, tomatoes and asparagus) providing moderate amounts. It’s said that eating foods rich in sulfur-containing amino acids helps with the body’s production of glutathione.