What Is Glutathione? Benefits, Uses & Why Your Body Needs It The Lookshop Aesthetics Studio Glutathione You Are The Healer 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 Glutathione is the body's primary internal antioxidant, made using the amino acid cysteine, and it helps protect cells from oxidative stress. Beyond detoxification, research shows glutathione is involved in thyroid hormone metabolism,