Selenium is essential for the functioning of glutathione peroxidase (GSH peroxidase), one of the body's main antioxidants. Selenium has a close relationship with vitamin E. Vitamin E performs similar functions to GSH peroxidase, including protecting cell membranes by detoxifying peroxides and other free radicals. GSH peroxidase may also regenerate oxidized vitamin E in microsomal membranes.

L-Selenomethionine is a form of selenium that contains the amino acid l-selenomethionine. This is a yeast free form of selenium that is more bioavailable then other forms of selenium. Recently the FDA has authorized the health claim that selenium helps with some forms of cancer. Selenomethionine can also reduce the risk of heart disease. Studies have suggested that topical applications of selenomethionine with or without vitamin E may help heal sun burns and other skin damage due to the over exposure of sun light.