Pectin

Pectin is a polysaccharide used mainly as a thickener/film-former in leave-on and rinse-off products, typically at low concentrations (about 0.1–2%), and it is generally well tolerated in patch-test settings. While it lacks the intrinsic reactivity of acids, fragrances, or strong preservatives, any film-forming plant-derived polymer can rarely sting or feel tight on compromised eczema skin, so I score it as very gentle rather than completely inert for safety. Safety Notes: In commercial skincare, pectin is most often used as a secondary rheology modifier/film former in leave-on serums, lotions, and masks at very low levels (~0.01–0.3%), where it subtly boosts viscosity and skin feel without forming a true gel. Higher levels are seen in consumer-available gelled products (especially peel-off or “jelly” masks, wash-off masks, and some thick gel textures) where pectin functions as a primary gellant/film former, typically ~1–3% and up to about 5% in high-structure formulations. Above this, consumer cosmetics tend to become impractically stiff/tacky or unstable unless paired with specific sugar/acid systems, so >5% is uncommon in real-world OTC skincare.