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Health Benefits, Uses, Side Effects & More


Updated May 16, 2014

Written or reviewed by a board-certified physician. See About.com's Medical Review Board.

Spirulina is a type of blue-green algae available in dietary supplement form. Claims for spirulina benefits include the treatment of various health conditions, as well as the promotion of weight loss. However, few human studies have actually explored spirulina's health benefits, and there is insufficient evidence to show that it helps with weight loss.

Spirulina contains a number of nutrients, including B-complex vitamins, beta-carotene, and vitamin E. Spirulina is high in protein and also contains antioxidants, minerals, and chlorophyll.

Health Benefits of Spirulina

To date, few human studies have explored spirulina's health benefits. However, test-tube studies and animal-based research suggest that spirulina may help with the following conditions:

1) Allergies

Spirulina holds some promise in the treatment of allergic rhinitis (nasal allergies), according to a research review published in 2009. Indeed, a previously published study of patients with allergic rhinitis found several benefits for spirulina consumption (including improvement in symptoms like nasal discharge, sneezing, congestion, and itching).

Find out about other Natural Remedies For Allergies.

2) Diabetes

In a 2008 study involving 37 people with type 2 diabetes, researchers found that those assigned to 12 weeks of spirulina supplementation experienced a significant reduction in blood-fat levels. Spirulina benefits also included a decrease in inflammation and, for some patients, a decrease in blood pressure and cholesterol.

See Natural Treatments For Diabetes.

3) Oral Cancer

Spirulina may offer some protection against oral cancer, according to one small study of tobacco chewers with precancerous oral lesions. For 12 months, study members took either a daily dose of spirulina or a placebo. By the study's end, the lesions cleared up in 20 of the 44 participants who'd consumed spirulina (compared to three of the 43 participants who'd been assigned to the placebo group).

4) Weight Loss

Despite widespread marketing claims that spirulina can suppress appetite, there is insufficient evidence to show that spirulina can boost weight loss.

See Natural Remedies For Weight Loss for other ways to lose weight.

Common Uses for Spirulina

Spirulina proponents claim that the benefits of spirulina include treatment and/or prevention of the following health problems:

  • attention deficit hyperactivity disorder
  • cancer
  • fatigue
  • high cholesterol
  • viral infections

Purported spirulina benefits also include weight loss and stimulation of the immune system.

Side Effects

Although few adverse effects are associated with use of spirulina, consuming spirulina may cause headache, muscle pain, sweating, and insomnia in some cases.


As with all supplements, it's also important to consult your health-care provider before using spirulina in combination with other medications and/or supplements.

Learn more about supplement safety.

Forms of Spirulina

Spirulina is often sold in powder form, but it's also available in capsules, tablets, and other natural products (including juices).

Although there are a large number of blue-green algae species commonly referred to as "spirulina," most spirulina supplements contain Aphanizomenon flos-aquae, Sprirulina maxima, and/or Spirulina platensis.


Cingi C, Conk-Dalay M, Cakli H, Bal C. "The effects of spirulina on allergic rhinitis." Eur Arch Otorhinolaryngol. 2008 265(10):1219-23.

Lee EH, Park JE, Choi YJ, Huh KB, Kim WY. "A randomized study to establish the effects of spirulina in type 2 diabetes mellitus patients." Nutr Res Pract. 2008 2(4):295-300.

Man LX. "Complementary and alternative medicine for allergic rhinitis." Curr Opin Otolaryngol Head Neck Surg. 2009 17(3):226-31.

Mathew B, Sankaranarayanan R, Nair PP, Varghese C, Somanathan T, Amma BP, Amma NS, Nair MK. "Evaluation of chemoprevention of oral cancer with Spirulina fusiformis." Nutr Cancer. 1995;24(2):197-202.

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