Table of Contents > Herbs & Supplements > Spirulina Print



Also listed as: Aphanizomenon flos-aquae, Blue-green algae, Arthrospira plantensis
Related terms

Related Terms
  • AFA, Aphanizomenon flos-aquae, Arthrospira platensis, BGA, blue-green algae, calcium, copper, cyanobacteria, cyanobacterium, dihe, free fatty acids, iron, ImmulinaT, klamath, magnesium, manganese, Microcystis aeruginosa, M. wesenbergii, monogalactosyl monoacylglycerols, Multinal, nickel, Nostoc spp., lead, phosphatidylglycerols, phycocyanin, phytoplankton, plant plankton, pond scum, prokaryotic cyanobacterium, Selen-Spirulina, Spirulina fusiformis, S. maxima, S. platensis, Spiruline, tecuitatl, sulfoquinovosyl diacylglycerols, zinc.
  • Note: Non-spirulina species, such as Anabaena species, Aphanizomenon species, and Microcystis species are possibly unsafe because they are usually harvested naturally and may be subject to contamination.

  • The term spirulina refers to a large number of cyanobacteria or blue-green algae. Both Spirulina spp. and non-Spirulina spp. fall into the classification of cyanobacteria and include: Aphanizomenon spp., Microcystis spp., Nostoc spp., and Spirulina spp. Most commercial products contain Aphanizomenon flos-aquae, Sprirulina maxima, and/or Spirulina platensis. These algae are found in the warm, alkaline waters of the world, especially of Mexico and Central Africa. Spirulina spp. are most often grown under controlled conditions and are subject to less contamination than the non-spirulina species that are harvested naturally.
  • Spirulina is a rich source of nutrients, containing up to 70% protein, B-complex vitamins, phycocyanin, chlorophyll, beta-carotene, vitamin E, and numerous minerals. In fact, spirulina contains more beta-carotene than carrots. Spirulina has been used since ancient times as a source of nutrients and has been said to possess a variety of medical uses, including as an antioxidant, antiviral, antineoplastic, weight loss aid, and lipid-lowering agent. Preliminary data from animal studies demonstrate effectiveness for some conditions as well as safety, although human evidence is lacking. Based on available research, no recommendation can be made either for or against the use of spirulina for any indication.

Evidence Table

These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider. GRADE *

Anti-inflammatory properties of spirulina may improve certain aspects of nasal allergies. However, further high-quality studies are needed to confirm these findings.


Spirulina extract plus zinc may be useful for the treatment of arsenic poisoning. Additional research is needed to confirm these findings.


Preliminary study of people with type 2 diabetes mellitus reports that spirulina may reduce fasting blood sugar levels after two months of treatment. More research is needed before a firm conclusion can be drawn.


Super blue-green algae may decrease eye lid spasms but additional high-quality research is necessary to make a recommendation.


In animal studies, spirulina has been found to lower blood cholesterol and triglyceride levels. Preliminary poor-quality studies in humans suggest a similar effect. Better research is needed before a firm conclusion can be drawn.


Spirulina has been studied as a food supplement in infant malnutrition but results have been mixed. More research is necessary in this area.


Preliminary research has not clearly shown benefits of spirulina in the treatment of oral leukoplakia.


Spirulina is a popular therapy for weight loss and is sometimes marketed as a "vitamin enriched" appetite suppressant. However, little scientific information is available on the effect of spirulina on weight loss in humans.


There is currently inadequate evidence to recommend the use of spirulina in chronic fatigue syndrome.


Preliminary study of spirulina for chronic viral hepatitis shows negative results.

* Key to grades

A: Strong scientific evidence for this use
B: Good scientific evidence for this use
C: Unclear scientific evidence for this use
D: Fair scientific evidence for this use (it may not work)
F: Strong scientific evidence against this use (it likley does not work)

Tradition / Theory

The below uses are based on tradition, scientific theories, or limited research. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider. There may be other proposed uses that are not listed below.

  • Anaphylaxis (severe allergic reaction) prevention, anemia, antibacterial, antifungal, anti-inflammatory, antioxidant, antiviral, anxiety, arthritis, atherosclerosis (hardening of the arteries), attention deficit hyperactivity disorder (ADHD), autoimmune disorders, bowel health, brain damage, cancer prevention, cancer treatment, cirrhosis, colitis, cytomegalovirus infection, depression, digestion, doxorubicin cardiotoxicity, energy booster, fatigue, fatty liver, fibromyalgia, . infection, hair loss, heart disease, herpes simplex-1 virus (HSV-1), high blood pressure, HIV, immune system enhancement, infectious disease, influenza, iron deficiency, ischemic injury (ischemic reperfusion injury), kidney disease, lead-induced organ damage, leukemia, liver protection, measles, memory improvement, mood stimulant, mumps, nerve damage, obstetric and gynecological disorders, Parkinson's disease, pneumonia, premenstrual syndrome, radiation sickness, radiation-induced damage, skin disorders, stomach acid excess, stress, ulcers, vitamin and nutrient deficiency, warts, wound healing, yeast infection.


Adults (18 years and older)

  • Spirulina has typically been taken by mouth two to three times daily with meals in doses of 1-1.4 grams for diabetes mellitus (type 2), high cholesterol, or oral leukoplakia (pre-cancerous mouth lesions). For weight loss, 200 milligrams of spirulina tablets by mouth three times daily, taken just before eating, has been studied. Two grams of spirulina has been used for nasal allergies. For arsenic poisoning, twice daily doses of 250 milligrams of spirulina extract plus 2 milligrams of zinc may be helpful.

Children (under 18 years old)

  • Not enough scientific information is available to advise the safe use of spirulina in children.


The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.


  • Avoid use in individuals with known allergy to spirulina, blue-green algae species, or any of their constituents.

Side Effects and Warnings

  • Few side effects have been reported with spirulina use. The most frequently reported adverse effects are headache, muscle pain, flushing of the face, sweating, and difficulty concentrating. These have been described in people taking 1 gram of spirulina by mouth daily. Skin reactions have also been reported.
  • Blue-green algae, especially types that are usually harvested in uncontrolled settings (Anabaena spp., Aphanizomenon spp., and Microcystis spp.), may be contaminated with heavy metals. Liver damage, diarrhea, and vomiting have been reported.
  • The amino acid phenylalanine in blue-green algae may cause an adverse reaction in people with the genetic condition phenylketonuria (PKU), and should be used cautiously.

Pregnancy and Breastfeeding

  • There is not enough information to recommend the safe use of spirulina during pregnancy or breastfeeding. In mice, diets containing up to 30% spirulina are not reported to cause harmful effects to either the mother or the offspring. However, reliable human studies addressing safety during pregnancy or breastfeeding are not available.


Interactions with Drugs

  • Spirulina may interact with certain drugs taken for immune system disorders, high blood pressure (ACE inhibitors), inflammation, diabetes, high cholesterol, neurologic conditions, and viruses as well as blood thinners and antihistamines.
  • Spirulina may also interact with drugs taken for weight loss, cancer, heart disorders, and osteoporosis. There is a possible interaction when taking spirulina with drugs that are potentially toxic to the kidney.

Interactions with Herbs and Dietary Supplements

  • Small increases in calcium levels have been reported, although it is unclear whether this is due to the effects of spirulina alone. Use of spirulina and calcium supplements together may further increase calcium levels.
  • Spirulina may increase levels of protein, iron, gamma-linolenic fatty acid, carotenoids, vitamin B1, vitamin B2, vitamin B12, and vitamin E.
  • Spirulina may interact with certain dietary supplements taken for immune system disorders, high blood pressure, cancer, weight loss, heart disorders, inflammation, diabetes, high cholesterol, neurologic conditions, blood clots, and viruses. Use cautiously with antihistamines or any herb or supplement that is potentially toxic to the kidney.

  • This information is based on a systematic review of scientific literature edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (

  1. Baicus C, Baicus A. Spirulina did not ameliorate idiopathic chronic fatigue in four N-of-1 randomized controlled trials. Phytother Res 2007 Jun;21(6):570-3.
  2. Hernandez-Corona A, Nieves I, Meckes M, et al. Antiviral activity of Spirulina maxima against herpes simplex virus type 2. Antiviral Res 2002;56(3):279-285.
  3. Iwasa M, Yamamoto M, Tanaka Y, et al. Spirulina-associated hepatotoxicity. Am J Gastroenterol 2002;97(12):3212-3213.
  4. Jensen GS, Ginsberg DI, Drapeau C. Blue-green algae as an immuno-enhancer and biomodulator. J Amer Nutraceut Assoc 2001;3(4):24-30.
  5. Mani UV, Desai S, Iyer U. Studies on the long-term effect of spirulina supplementation on serum lipid profile and glycated proteins in NIDDM patients. J Nutraceut 2000;2(3):25-32.
  6. Mathew B, Sankaranarayanan R, Nair PP, et al. Evaluation of chemoprevention of oral cancer with Spirulina fusiformis. Nutr Cancer 1995;24(2):197-202.
  7. Misbahuddin M, Islam AZ, Khandker S, et al. Efficacy of spirulina extract plus zinc in patients of chronic arsenic poisoning: a randomized placebo-controlled study. Clin Toxicol (Phila) 2006;44(2):135-41.
  8. Romay C, Armesto J, Remirez D, et al. Antioxidant and anti-inflammatory properties of C-phycocyanin from blue- green algae. Inflamm Res 1998;47(1):36-41.
  9. Samuels R, Mani UV, Iyer UM, et al. Hypocholesterolemic effect of spirulina in patients with hyperlipidemic nephrotic syndrome. J Med Food 2002;5(2):91-96.
  10. Shih SR, Tsai KN, Li YS, et al. Inhibition of enterovirus 71-induced apoptosis by allophycocyanin isolated from a blue-green alga Spirulina platensis. J Med Virol 2003;70(1):119-125.
  11. Watanabe F, Takenaka S, Kittaka-Katsura H, et al. Characterization and bioavailability of vitamin B12-compounds from edible algae. J Nutr Sci Vitaminol (Tokyo) 2002;48(5):325-331.
  12. Yang HN, Lee EH, Kim HM. Spirulina platensis inhibits anaphylactic reaction. Life Sci 1997;61(13):1237-1244.

Copyright © 2011 Natural Standard (

The information in this monograph is intended for informational purposes only, and is meant to help users better understand health concerns. Information is based on review of scientific research data, historical practice patterns, and clinical experience. This information should not be interpreted as specific medical advice. Users should consult with a qualified healthcare provider for specific questions regarding therapies, diagnosis and/or health conditions, prior to making therapeutic decisions.

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