Potent Free Radical ScavengerHealthy Immune System ResponseAstaxanthin is a naturally occurring carotenoid with a unique structure that is known to be a potent free radical scavenger. Because Astaxanthin freely crosses the blood-brain and blood-retina barriers, it can neutralize free radicals in the eye and central nervous system. Scientific studies also demonstrate that astaxanthin can support the body's healthy and balanced immune system responses. This NOW product features Zanthin, which can help to support overall ocular health and promote a healthy nervous system.