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Supplement Forms/Alternate Names
Principal Proposed Uses
Other Proposed Uses
The supplement called spirulina consists of one or more members of a family of blue-green algae. The name was inspired by the spiral shapes in which these plants array themselves as they grow.1 Other blue-green algae products are also available on the market, and they are discussed in this article as well.
Spirulina grows in the wild in salty lakes in Mexico and on the African continent. It reproduces quickly, and because the individual plants tend to stick together, it is easy to harvest. Records of the Spanish conquistadors suggest that the Aztecs used spirulina as a food source; we also know that the Kanembu people of Central Africa harvested it from what is now called Lake Chad.
This plant contains high levels of various B vitamins, beta-carotene, other carotenoids, and minerals, including calcium, iron, magnesium, manganese, potassium, and zinc. It is also a source of gamma-linolenic acid (GLA) . Spirulina is a rich source of protein—dried spirulina contains up to 70% protein by weight 2 —but you'd have to eat an awful lot of spirulina capsules to obtain a significant amount of protein this way. Spirulina also contains vitamin B12, a nutrient otherwise found almost exclusively in animal foods. However, there's a catch: the B 12in spirulina is not absorbable.3
Spirulina has not been proven effective for any medical condition, and there are significant safety concerns involving all forms of blue-green algae (see Safety Issues).
Last reviewedSeptember 2014by EBSCO CAM Review Board
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.