A blue-green algae found in the oceans or growing in alkaline lakes, spirulina is a nutritious green superfood. Dried spirulina delivers protein, vitamins, minerals and essential fatty acids. Spirulina is used to support immune system health and for general nutrition. It is a complete protein because it features all of the essential amino acids. It is also a natural source of gamma-linolenic acid (GLA). Swanson Greens 100% Certified Organic Spirulina delivers the ocean’s greenest and healthiest superfood in 500 mg tablets.