Chondrus Crispus

Chondrus crispus (Irish moss) is primarily a film-forming thickener/skin-conditioning seaweed extract used at low percentages, and in clinical experience it is generally well tolerated with low irritancy potential. However, as a botanical/marine-derived extract it can contain trace proteins/iodine and variable constituents that occasionally trigger stinging or dermatitis in highly reactive or eczema-prone patients, so it is not truly inert. For patient safety in severe sensitivity populations, I score it as very gentle rather than exceptionally gentle. Safety Notes: Chondrus crispus (Irish moss/seaweed extract, often supplying carrageenan-type polysaccharides) is commonly used at very low levels (~0.05–0.5%) in leave-on lotions/serums and rinse-off cleansers primarily for viscosity/film-forming and skin-feel benefits. In higher-solids gel creams, masks, and “seaweed” treatment products marketed to consumers, total Chondrus-derived material can reach ~2–5% (especially when used as a primary gelling/texture and sensory component), with higher levels generally limited by tackiness, odor/color, and stability constraints rather than regulation.