Selenium 50 mcg by Solaray is derived from Organically Bound Selenium Yeast.Selenium activates an antioxidant enzyme called glutathione peroxidase, which helps protect the body from cancer. Selenium has also induced “apoptosis” (programmed cell death) in cancer cells. A recent study following over 1,300 people found that those given 200 mcg of yeast-based selenium per day for seven years had a 50% drop in the cancer death rate. Another recent trial found that men exposed to the most dietary selenium developed 65% less advanced prostate cancer.Selenium is also essential for healthy immune functioning. As a result, selenium supplementation has reduced the incidence of hepatitis. Selenium supplementation stimulates the activity of white blood cells-primary components of the immune system. Selenium is also needed to activate thyroid hormones.Ingredients – per capsule: Selenium (as Organically Bound Selenium Yeast) 50 mcgOther Ingredients: Brewer’s yeast, gelatin (capsule) and magnesium stearate