Global Healing Center's Selenium supplement is made from a pure selenium extract drawn from 100% certified organic mustard seed, making it one of the best selenium supplements available. This organic selenium product is highly bioavailable and vegan-friendly. Selenium is an essential trace mineral that supports thyroid health and can even act as a powerful antioxidant within the body. Daily consumption of selenium pills will help support normal thyroid and immune function in healthy individuals, encourage normal oxygen levels in the heart, reduce redness and swelling and so much more.