What is glutathione? Know as the most important antioxidant in the body, glutathione is an essential antioxidant manufactured in all cells, but primarily in the liver. It is essential because it What are Glutathione Benefits? Uses & Side effects Explained Amazon.com: Immunocal Glutathione Precursor Supports Natural Glutathione Production Immune & Antioxidant Support, Cellular Health Sugar Free, Lactose Free 30 Servings : Health & Household Benefits of Glutathione." Glutathione is a compound involved as a coenzyme in oxidationreduction reactions in cells. It is a tripeptide derived from 3 amino acids: Cysteine, glutamate (from glutamic acid), and glycine.