Based on 6 first-hand reports and 4 meta-analyses & systematic reviews in the medical literature. Ranked #2944 of 4,149 overall.
Of reports that state an outcome, 0% are positive.
Of the people who reported each effect, the share who said it got better.
Systematic reviews and meta-analyses from PubMed, with their published conclusions.
At least one meta-analysis, or 5+ randomized controlled trials. The grade measures how much human research exists — read the conclusions below for what it found.
Conclusion: A meta-analysis of 4 studies with no baseline control effect did not show significant results on both blood pressure. The evidence to support this systematic review meta-analysis requires more investigation and future large scale RCT clinical trial to confirm the results.
PubMed 35870546 ↗Conclusion: Toxin production by cyanobacteria is a health concern for both recreational water users and BGAS consumers. Recommendations include: limit harvesting of AFA to months when toxicity is lowest, include AFA in cell counts during visible blooms, and properly identify cyanobacteria species using 16S rRNA methods when toxicity levels are higher than advisory levels.
PubMed 29933577 ↗Conclusion: Further high-quality research is needed to evaluate the effects of spirulina consumption on performance, the immune system and recovery in athletes and active people. [https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=262896], identifier [CRD42021262896].
PubMed 36590230 ↗Conclusion: Conclusions: Chlorella consumption may modulate gut microbiota composition and function, potentially influencing brain-related processes. However, the available literature lacks studies simultaneously addressing both gut microbiota and brain health parameters limiting the understanding of the underlying physiological mechanisms.
PubMed 42356400 ↗As stated by users — not a recommendation. Follow the label or your doctor.
How often each side effect came up across all reports.
First-hand experiences, quoted verbatim. We show one positive and one negative where both exist.
User data from public discussions; research from PubMed. Information only, not medical advice — talk to a doctor before starting, stopping or combining anything. Data updated October 3, 2026. How we rate