Phycocyanin, a pigment-protein complex derived primarily from blue-green algae such as Spirulina, has been studied for its antioxidant properties, particularly its capacity to scavenge free radicals and reduce oxidative stress. Laboratory and animal studies have demonstrated that phycocyanin exhibits strong free radical scavenging abilities, primarily due to its unique chemical structure, which allows it to donate electrons and neutralize reactive oxygen species (ROS). Several in vitro experiments have shown that phycocyanin can inhibit lipid peroxidation and protect cellular structures from oxidative damage.

In animal models, administration of phycocyanin has been associated with reduced markers of oxidative stress and improved antioxidant enzyme activities, such as superoxide dismutase and catalase. Some studies also suggest protective effects against chemically-induced organ damage, attributed to its antioxidant action. However, human clinical data are limited; while Spirulina (which contains phycocyanin) supplementation has shown antioxidant effects in some small trials, direct evidence isolating phycocyanin in humans is sparse and more high-quality clinical research is necessary to confirm efficacy and establish optimal dosing.

In summary, there is moderate scientific evidence from preclinical research supporting the use of phycocyanin for mitigating free radical damage, but clinical validation in humans remains limited. Its use for this purpose is primarily justified by laboratory and animal studies rather than robust human trials.