Agar

Agar is a polysaccharide gelling/thickening agent used at low concentrations (typically well under 1%) and is generally non-reactive and non-sensitizing in topical products. Clinical experience and patch-test data suggest irritation is uncommon, but in highly compromised barriers (e.g., active eczema) any film-former can occasionally contribute to tightness or stinging from the overall formula. Given the Foundation’s safety emphasis, it fits best as very gentle rather than completely inert. Safety Notes: Agar is used in consumer skincare mainly as a gelling/thickening and stabilizing hydrocolloid; in emulsions and gel-creams it is often present at very low levels (~0.05–0.3%) to provide viscosity and suspension with minimal sensory impact. In high-structure water gels, jelly masks, and “peelable/jelly” specialty products available OTC, formulas can push into the ~1–3% range, and the strongest consumer-available set-style gels can reach ~4–5% where agar functions as the primary gellant (higher levels become very rigid/brittle and are uncommon in cosmetics). Agar is used primarily in leave-on and wash-off textures similarly, but the highest levels are most often seen in mask/gel formats rather than standard daily leave-on emulsions.