Selenium is an essential trace mineral that is required for many important biochemical functions in the body. In humans, selenium functions as a coenzyme for the antioxidant enzyme glutathione peroxidase. Glutathione peroxidase helps neutralize harmful peroxide free radicals. Selenium also plays an important role in the production of thyroid hormones. Selenium is a coenzyme for the enzymes which are responsible for the synthesis of thyroid hormones. These enzymes are important for the regulation of basal metabolic rate (resting metabolic rate-rate at which you burn calories). Studies show Selen Excell helps support the body's antioxidant defenses and contributes to the growth of normal, healthy cells.