C-Phycocyanin

C-phycocyanin belongs to a family of phycobiliproteins that harvest light energy during photosynthesis in cyanobacteria and red algae. It is composed of protein subunits bound to a chromophore called phycocyanobilin, which is structurally similar to the bile pigments bilirubin and biliverdin. During digestion, phycocyanobilin appears to be cleaved from the protein backbone and absorbed in small amounts. In circulation it is hypothesized to inhibit NADPH oxidase, an enzyme that produces reactive oxygen species in cells. Through this mechanism, phycocyanin may exert antioxidant and anti-inflammatory effects observed in preclinical models. Human evidence is more limited but consistent: small clinical trials show reductions in markers of oxidative stress and modest improvements in exercise recovery. The intact protein is poorly absorbed; most systemic effects are attributed to the chromophore.

There is no RDA. Supplement doses range from 100 mg to 1,000 mg of standardized C-phycocyanin daily, or 3 to 10 grams of whole spirulina (which is roughly 15 to 20 percent phycocyanin by weight). Clinical studies have used 1 to 2 grams of phycocyanin daily over 4 to 12 weeks.

C-phycocyanin can be taken any time of day, with or without food. Splitting doses (morning and evening) may help maintain steady plasma levels. Athletes sometimes take it pre- or post-exercise. No clear sleep impact.

Generally well tolerated. Most side effects reported with spirulina (mild GI upset, headache, skin flushing) likely apply. The primary safety concern is contamination of source algae with microcystins, heavy metals, or non-spirulina cyanobacteria. Use products with documented third-party purity testing. No formal Tolerable Upper Intake Level has been established.

C-phycocyanin may theoretically interact with immunosuppressants (due to immunomodulation) and may potentiate anticoagulants in animal models. Human clinical interaction data are limited.