Selenium is an essential trace element and a powerful antioxidant it works by mopping up cell damaging unstable oxygen molecules known as free radicalsfree radicals are linked to cell damage and the potential effects of aging such as skin wrinkles our formula contains 200mcg of selenium double that offered by our competitors although we only need small amounts of selenium combining it with the vitamins a c and e it enhances its potential effects vitamin a as non toxic beta carotene is a