Astaxanthin is a vibrantly deep red carotenoid naturally found in marine organisms such as micro-algae, salmon, trout, shrimp, crayfish, and crustaceans. The richest source of astaxanthin is found in the micro-alga Haematococcus pluvialis. It is an anti-oxidant and is known for promoting health and protecting against cellular damage, especially in the brain and vascular system. It may be used to prevent aging, help maintain healthy skin, treat breast cancer, support high-performance exercise, reduce fatigue, prevent heart disease, reduce inflammation and pain due to arthritis, help with neurodegenerative conditions such as Alzheimer's, improve male fertility, protect against eye fatigue, increase blood flow to eye tissues, boost brain health, help with diabetes, protect against damage to immune cells, and support immune system function. A special feature of astaxanthin is that it is able to cross the blood-brain and blood-retinal barrier to protect both the brain and eyes (something that is rather unusual for carotenes).