Natural Factors Astaxanthin Extra Strength - 12 mg - Natural Factors Astaxanthin 12 mg is our highest-potency astaxanthin formula, with 100% naturally sourced astaxanthin from microalgae. Astaxanthin is a fat-soluble carotenoid pigment best known for its high antioxidant ability. As a source of antioxidants, it helps protect against the oxidative damage caused by free radicals. Just one convenient softgel per day delivers a full dose of non-GMO astaxanthin in a base of flax oil for easy absorption.