Glutathione is an essential component of your cells, with low glutathione levels, cells cannot perform many of their functions properly. Although glutathione functions in dozens of roles in our metabolism, the major functions can be summarized in four areas: It is the major antioxidant produced by the body. Antioxidants such as vitamins C or E cannot be made by your body and in fact could not work properly if glutathione were not present. Our immune systems depend on a steady supply of glutathione. Without it, our immune defenses become weakened. It is important in detoxifying many substances including heavy metals, breakdown products of cigarettes and automobile exhaust, many cancer-causing agents, and a multitude of pollutants and toxins we encounter on a daily basis. The major source of energy produced in our cells is derived from tiny structures called mitochondria. These mitochondria would literally burn up without the presence of glutathione.