Porphyridium Cruentum Extract Average Plant extracts Anti-Ageing Porphyridium Cruentum Extract description Extract derived from a type of red algae. There is research showing components of red algae contain the omega-3 fatty acid eicosapentaenoic acid, the omega-6 fatty acid arachidonic acid, and other skin-friendly ingredients such as polysaccharides. Whether or not the entire red algae extract provides benefit when applied topically on skin is not known. Related ingredients: Algae