Porphyra umbilicalis (nori) extract is a red‐algal active valued for its high content of mycosporine-like amino acids (MAAs) — notably porphyra-334 and shinorine — and sulfated galactan polysaccharides (porphyran). MAAs are low-molecular, water-soluble UV-absorbing chromophores (λ_max typically ~310–360 nm) that dissipate energy non-radiatively and quench reactive oxygen species (ROS). In topical systems they function as photostable antioxidant boosters and photo-stress mitigators, helping to limit UV-induced oxidative damage and downstream matrix metalloproteinase (MMP) upregulation implicated in photoaging. The polysaccharide fraction contributes film-forming, humectant, and barrier-support properties that reduce transepidermal water loss (TEWL) and improve sensorial slip, making nori extract relevant to daily wear serums, day creams, after-sun care, and SPF-adjacent formats (as a supportive antioxidant/UV-booster in combination with approved UV filters).

In hair care, Nori Extract’s anionic polysaccharides form hydrating, flexible microfilms along the fiber, improving combability, surface smoothness, and manageability while helping to curb static and frizz. The antioxidant/anti-photo-oxidative activity can also help protect color vibrancy and fiber lipids from environmental stress. Formulators leverage the extract in rinse-off and leave-on systems — shampoos, conditioners, scalp essences, and lightweight styling gels — where it enhances glide, provides light hold through film formation, and supports a healthier scalp environment with gentle, non-sensitizing actives.