Porphyra Umbilicalis Extract

Porphyra umbilicalis (red algae) extract is typically used at low concentrations as an antioxidant/soothing, film-forming humectant, and it is generally well-tolerated in standard leave-on products. However, botanical extracts can trigger stinging or dermatitis in a small subset of highly reactive or eczema-prone patients due to variable bioactive compounds and potential trace impurities, so I score it as gentle rather than “very gentle” for compromised skin. Safety Notes: In real-world OTC skincare, Porphyra Umbilicalis Extract (red algae/nori extract) is often used as a minor antioxidant/soothing adjunct in leave-on moisturizers, serums, and sunscreens at ~0.01–0.1%, reflecting supplier-recommended use levels and cost/odor/color constraints. More “algae-forward” consumer formulations (e.g., hydrating masks, gel-creams, after-sun and anti-pollution products) commonly run ~0.5–1.5% when the extract is a featured claim ingredient. The upper end (~3%) is observed in high-strength OTC leave-on products marketed around marine/algae actives; higher levels are uncommon due to stability, sensory (marine odor, tack), and potential color shift, and rinse-off formats typically sit toward the lower-to-mid part of the range because of short contact time.