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Chlorella is a freshwater algae that is commonly supplemented by vegan populations (similar to Spirulina). Chlorella appears to be a bioavailable source of both Iron and Vitamin B12, and may have other benefits.

Our evidence-based analysis on chlorella features 39 unique references to scientific papers.

Research analysis led by .
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Last Updated:

How to Take

Recommended dosage, active amounts, other details

Supplementation of chlorella appears to be in the range of 6-10g daily. It is unsure why this dose is chosen, but it appears to be somewhat effective. Higher doses have not been sufficiently tested and the optimal dose of supplemental chlorella is not known.

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Human Effect Matrix

Unlocked for Examine members

The Human Effect Matrix summarizes human studies to tell you what effects Chlorella has on your body, how much evidence there is, and how strong these effects are.

Full details are available to Examine members.
Grade Level of Evidence
Robust research conducted with repeated double-blind clinical trials
Multiple studies where at least two are double-blind and placebo controlled
Single double-blind study or multiple cohort studies
Uncontrolled or observational studies only
Level of Evidence
? The amount of high quality evidence. The more evidence, the more we can trust the results.
Outcome Magnitude of effect
? The direction and size of the supplement's impact on each outcome. Some supplements can have an increasing effect, others have a decreasing effect, and others have no effect.
Consistency of research results
? Scientific research does not always agree. HIGH or VERY HIGH means that most of the scientific research agrees.
grade-c Minor - See study
No remarkable effects following oral ingestion of chlorella, although some may be present
grade-c Minor Moderate See all 3 studies
Might reduce blood pressure in some instances but does not appear remarkably potent.
grade-c Minor - See study
Increase in salivary IgA suggests an immune enhancing effect; no comparison to an active control.
grade-c - - See study
No significant effects on fat mass
grade-c - - See study
Has once failed to modify the DNA damage observed in male smokers
grade-c - - See study
No significant influence on heart rate has been detected
grade-c - - See study
Has once failed to act effectively as a vaccine adjuvant
grade-c - - See study
No significant effects on body weight
grade-d Minor - See study
Study in pregnant women, it did have efficacy but more studies are required to assess chlorella overall.
grade-d Minor - See study
Reduced proteinuria in pregnant women (possibly indiciative of kidney protective effects); more studies would be prudent as to include comparators or use in other contexts.
grade-d Minor - See study
May be secondary to the Iron content, somewhat effective in pregnant women. Requires more evidence, especially in anemics
grade-d Minor - See study
May have efficacy in reducing pain associated with fibromyalgia, but requires more evidence

Studies Excluded from Consideration

  • Excluded due to being highly confounded[1]

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Things to Note

Also Known As

Chlorella pyrenoidosa

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Click here to see all 39 references.