What is Doctor\'s Best Astaxanthin? Doctor\'s Best Astaxanthin is an antioxidant that supports healthy blood flow and vessel integrity, promotes a healthy, integrated immune response, and supports memory and other brain functions. Astaxanthin also enhances vision and relieves eye fatigue. Astaxanthin has beneficial effects on cell membranes that manage important life functions. The body cannot make astaxanthin, it must be consumed either through diet or supplementation. Astaxanthin is made by algae and moves up the food chain when the algae are consumed as food. It gives the red color to seafood such as salmon, trout, crab, shrimp, lobster, and krill, but these sources of astaxanthin are not common in most diets. Doctor\'s Best is pleased to offer this nutrient in its natural form, as a concentrate from the microalga Haematococcus pluvialis. How does it work? The molecular structure of astaxanthin is long and thin, with both ends having \"polar\" groups that are compatible with water while the middle segment is \"nonpolar\" and not water-compatible. This molecular structure allows astaxanthin to move into cell membranes without substantially affecting the membrane structure, astaxanthin is able to provide potent protection against cell damage, like the damage caused by free radicals. All cells have membranes and it is vital to maintain the health of these membranes so that the cell may function properly. Every cell membrane is an ultrathin sheet of lipids into which enzymes and other catalytic proteins are inserted. Intense metabolic activities within cell membranes typically generate highly reactive \"free radical\" substances. The damage caused by these free radicals can be attenuated by antioxidant activity. Astaxanthin provides cell membranes with a potent antioxidant defense against free radicals.Non-GMO, Vegan, Gluten free, Soy free.