Astaxanthin is often referred to as "the king of carotenoids". Carotenoids are a class of phytonutrients that are extremely important antioxidants that deactivate free radicals - atoms that can damage cells by reacting with other molecules. These antioxidants fight cancer, promote vision and normal growth & development, and are very anti-inflammatory - providing heavy support to our immune system. Astaxanthin is naturally found in certain marine plants and animals and is a powerful carotenoid.