Spirulina is a dietary supplement made from blue-green algae that is used both as a food and as a medicinal supplement to counteract unintentional weight loss and to ameliorate a variety of medical conditions including attention-deficit hyperactivity disorder, allergic rhinitis, hypertension, diabetes, stress, fatigue, anxiety and depression.
Spirulina is particularly rich in protein (60% to 70%) as well as vitamins, phycocyanin, beta-carotene, polyunsaturated fatty acids, linolenic acid, calcium and iron. The blue-green pigment phycocyanin has been proposed to be the active ingredient responsible for its medicinal properties. In animal experiments, spirulina has demonstrated antioxidant, anti inflammatory and analgesic effects and has been well tolerated without evidence of toxicity even in high doses.