Last Updated: September 28, 2022

Spirulina is a non-toxic blue-green algae. It's rich in nutrients and may have some general cardiovascular and anti-aging benefits. Its potentially potent immunomodulating properties may give it additional uses such as ameliorating allergies and asthma, but more research is needed.

Spirulina is most often used for

What is spirulina?

Spirulina is a type of non-toxic blue-green algae (cyanobacteria). It may refer to a number of different species in the Arthrospira genus, namely platensis and maxima. Spirulina is often used as a vegan source of protein and iron and is rich in a variety of other nutrients and phytochemicals. It is believed by some to provide vitamin B12, but it actually contains the dubious pseuodovitamin B12 which hasn't been shown to be effective. Spirulina has a few notable active components. The main ingredient is called phycocyanobilin, which makes up about 1% of spirulina. This compound mimics the body’s bilirubin compound, in order to inhibit an enzyme complex called nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. By inhibiting NADPH oxidase, spirulina provides potent antioxidative and anti-inflammatory effects.

What are spirulina's benefits?

Evidence suggests a general improvement in the basic components of the lipid panel: triglycerides, HDL, LDL, VLDL, and total cholesterol. It seems to reduce blood pressure by a small amount, and may have some meaningful effects on liver enzymes and overall liver health, though more research is needed on that. It also seems to improve general antioxidant status and reduce markers of oxidative stress, as well as some inflammatory markers. When people take spirulina, they tend to lose a small amount of weight, even if they're not trying to, and there's some evidence to suggest that it can help regulate appetite.

Because of its potentially potent immunomodulating properties, spirulina may have utility for preventing allergic reactions and treating asthma. However, there's only a small amount of research for these indications. Another possible benefit is improved athletic performance, with both resistance and endurance exercise, but the evidence is still preliminary.

What are spirulina's side-effects and drawbacks?

While most spirulina products are safe, there have been reports of contamination with toxic microcystins from other bacteria. It is advisable to ensure that any spirulina products have been throughly tested for safety before consumption. In general, spirulina is safe and adverse events aren't common in clinical trials.

What else is Spirulina known as?
Note that Spirulina is also known as:
  • Arthrospira maxima
  • Arthrospira platensis
Dosage information

The dose of spirulina used in studies examining its effects vary greatly. In general, 1-8 g per day of spirulina has been shown to have some effect. The specific doses depend on the condition its being used for:

  • For cholesterol, doses in the range of 1-8 g per day may be impactful
  • For muscle performance, doses of 2-7.5 g per day have been used
  • For blood glucose control, very mild effects have been seen with 2 g per day
  • Blood pressure may be affected at doses of 3.5-4.5 g per day
  • Effects for fatty liver have been seen at doses of 4.5 g per day

Spirulina is about 20% C-phycocyanin by weight, and about 1% phycocyanobilin by weight. The dosage range of 200mg/kg C-phycocyanin (1g/kg spirulina) converted to human equivalent doses from rats is approximately:

  • 11.0g for a 150lb person

  • 14.5g for a 200lb person

  • 18.2g for a 250lb person

Further research is needed to determine whether spirulina should be taken once a day, or in smaller doses, multiple times per day.

It is not recommended to exceed the highest dose mentioned above, as no clear benefits have been noted beyond that level.

Examine Database: Spirulina