Astaxanthin is a ketone or carotenoid, dark red in color, fat-soluble, insoluble in water, and soluble in organic solvents. It exists widely in the biological world, especially in the feathers of aquatic animals such as shrimps, crabs, fish and birds, and plays a role in color rendering. Astaxanthin is a non-vitamin A source carotenoid that cannot be converted into vitamin A in animals. Astaxanthin is a fat-soluble and water-soluble pigment that exists in shrimp, crab, salmon, algae and other marine organisms. The human body cannot synthesize astaxanthin by itself. It is the strongest antioxidant in nature. Its antioxidant activity is 550 times that of vitamin E and 10 times that of beta-carotene, so it is called the "king of antioxidants"!