Sargassum Filipendula Extract

An extract of a brown seaweed from the Sargassum genus. Brown algae contain fucoidans and alginates — polysaccharides that hold water well and are widely used in cosmetics for texture and film-forming. CosIng lists it as skin protecting. It usually appears in hydrating and soothing formulas as part of a marine blend.

The polysaccharides bind water and form a light, flexible film as the product dries. That film holds moisture at the surface and provides a physical buffer against the environment, which is what the protecting classification describes. Fucoidans have been studied for antioxidant and anti-inflammatory activity in the laboratory. Whether that carries through to a finished cosmetic depends on concentration and extraction method, which are rarely disclosed, so it is fair to treat this as a supporting ingredient.