Source Naturals Organic Spirulina, a complete vegetarian protein and source of healthy essential fatty acids, is cultivated under strict USDA Organic regulations, improving purity and potency. Spirulina, a blue-green algae used for centuries by indigenous cultures of both Central America and East Africa, is rich in amino acids, carotenoids, chlorophyll, minerals, and vitamins that in combination, support the immune system, provide antioxidant defense and promote healthy circulation. The tablets are 100% pure, binder-free organic spirulina.