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Limited evidenceLongevity & antioxidants

Phycocyanin

The blue pigment-protein from spirulina, sold as a concentrated antioxidant. Human data are thin: one safety trial of a phycocyanin-enriched extract and a handful of trials of whole spirulina, which is not the same product.

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What the science says

  • Safety at high doses Moderate evidence

    A randomized double-blind placebo-controlled study gave a high dose of phycocyanin-enriched spirulina extract and found no meaningful effect on coagulation or platelet activation, addressing a specific safety concern. This was a safety endpoint study, not an efficacy trial.

  • Anti-inflammatory and antioxidant effects Limited evidence

    A triple-blinded randomized placebo-controlled trial of whole spirulina in people with relapsing-remitting multiple sclerosis reported reductions in some inflammatory markers and improved quality-of-life scores. The intervention was whole spirulina, so the contribution of phycocyanin specifically is unknown.

Dosage & safety

Studied doseNo efficacy-based dose. The safety trial used a phycocyanin-enriched extract at doses corresponding to several grams of spirulina; commercial blue spirulina powders typically supply 500–2,000 mg/day.
SafetySpirulina products are generally well tolerated, but they can be contaminated with microcystins, heavy metals or other cyanobacteria — buy tested products. Avoid if you have phenylketonuria (phenylalanine content) or an autoimmune condition on immunomodulating treatment, and avoid in pregnancy without medical advice.

How to take it

TimingTiming does not matter.
With food?With or without food; nothing is established either way.
Worth knowingBuy only product tested for microcystins and heavy metals — cyanobacterial contamination is the real risk with spirulina-derived powders, not the phycocyanin itself.

Interactions

With medications

  • immunosuppressants

    Spirulina constituents stimulate immune signalling in laboratory studies, which could work against drugs given to suppress it. do not take it if you are on immunosuppressive therapy without asking your doctor

Well-established interactions only — this is not a complete list. Always tell your doctor and pharmacist what you take.

Frequently asked questions

Does phycocyanin have health benefits?

Human data on phycocyanin are thin, so the evidence is limited: the anti-inflammatory findings come from whole spirulina, not phycocyanin itself. One trial in multiple sclerosis reported lower inflammatory markers with spirulina.

Is phycocyanin safe for blood clotting?

A randomized placebo-controlled study found a high dose of phycocyanin-enriched spirulina extract had no meaningful effect on coagulation or platelet activation, a moderate-grade safety finding. It tested safety, not benefit.

How much blue spirulina or phycocyanin should I take?

Phycocyanin has no efficacy-based dose; commercial blue spirulina powders typically supply 500–2,000 mg/day, with or without food.

Who should avoid phycocyanin or blue spirulina?

Avoid phycocyanin products if you have phenylketonuria, are on immunosuppressants or immunomodulating treatment for an autoimmune condition, or are pregnant without medical advice. Buy only products tested for microcystins and heavy metals, which are the real contamination risk.

Scientific references

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