Allophycocyanin

ProteinPhycobiliproteinBest with a meal

What is it

Allophycocyanin (APC) is a blue-colored protein-pigment found in cyanobacteria (such as spirulina) and red algae. It functions as a light-harvesting protein in photosynthesis and is used in supplements, food coloring, and biomedical research as a fluorescent label.

Evidence for 1 use

AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.

Antioxidant / anti-inflammatory

Mixed Evidence

Preclinical evidence exists for both APC and phycocyanin. Human clinical data are limited and largely from whole-spirulina studies rather than isolated allophycocyanin.

How it works

Allophycocyanin is a tetrameric protein with bilin chromophores (linear tetrapyrroles) covalently attached. After oral ingestion, the protein is largely digested in the GI tract, releasing amino acids and free bilin chromophores. The intact pigment is not absorbed. In vitro and animal studies have shown that allophycocyanin and its breakdown products may have antioxidant, anti-inflammatory, and immunomodulatory effects. Most research interest is in the closely related phycocyanin (from spirulina), which shares structural and functional features.

Dosage

No established supplement dose. Often consumed as part of spirulina (3-10 g/day), which contains both phycocyanin and allophycocyanin.

When and how to take it

When consumed as part of spirulina, no specific timing requirement. Take with food to improve tolerability.

2 commercial forms

Compare the main delivery options and what they’re best suited for.

Isolated allophycocyanin

Higher purity; used mostly in research.

Protein is digested in GI tract

Spirulina (contains APC)

Most common consumer source.

Whole-food source

Safety

Generally considered safe as part of spirulina and other algae products. Quality and contamination concerns exist with poorly-sourced algae products (microcystins, heavy metals).

Who should be cautious

Pregnancy and lactation: rely on quality-tested algae sources only. People with phenylketonuria should note that algae contains phenylalanine. People on immunosuppressants should consult a clinician (immunostimulant potential).

Interactions

No significant interactions reported at typical doses.

Food sources

Spirulina

Amount
Variable
%DV
—

Red algae (Porphyra, dulse)

Amount
Variable
%DV
—

Frequently asked questions

What's the difference between phycocyanin and allophycocyanin?⌄

Both are blue protein-pigments in cyanobacteria. Phycocyanin is more abundant and more studied; allophycocyanin has a slightly different absorption spectrum and is structurally related.

Is allophycocyanin from spirulina safe?⌄

When consumed as part of quality-tested spirulina, yes. Always source spirulina from reputable suppliers due to potential microcystin contamination in poorly-sourced products.

References

Allophycocyanin on Wikidata — Wikidata link

Allophycocyanin on NIH DSLD (US supplement label database) — NIH Dietary Supplement Label Database link

Research on Allophycocyanin (PubMed search) — PubMed link

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Evidence-based·How we grade evidence

Disclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you’re pregnant, breastfeeding, on medications, or managing a chronic condition.