Spirulina
Commonly used for
Healthy AgingHeart HealthMetabolic Health
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The cheapest product is usually low quality, but more expensive doesn’t always mean better.
What is it? / Overview
Spirulina is a nutrient-dense cyanobacterium rich in phycocyanin, antioxidants, and protein. Clinical studies suggest modest improvements in blood pressure, lipid profiles, and oxidative stress markers though effects vary across populations.
How is it used? / Administration
Form: Arthrospira platensis — third-party tested for heavy metals and microcystins
Typical dose studied: 2–8 g/day (3–5 g/day most commonly studied)
Timing: With meals
Choose certified products free of heavy metals and cyanotoxins. Not a replacement for fruits and vegetables despite nutrient density.
How well does it work? / Evidence
? Emerging / limited evidence
Who should avoid it?
Avoid with: Organ transplant (on immunosuppression)
Interacts with: Immunosuppressants; Anticoagulants — theoretical caution due to vitamin K content in some products
Already taking it? Use certified products free of heavy metals and cyanotoxins. Note for phenylketonuria (PKU): some spirulina products contain measurable phenylalanine -- check the label if PKU applies.
Research & references
Hadi V et al. (2020). Spirulina and cardiometabolic risk factors meta-analysis. Complementary Therapies in Medicine. Shiri H et al. (2025). Spirulina and blood pressure meta-analysis. Phytotherapy Research. Limijadi EKS et al. (2025). Chlorella and spirulina for cardiovascular risk. Nutrients.
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