PEG-20 Glyceryl Triisostearate Good Cleansing Agent Hydration PEG-20 Glyceryl Triisostearate at a glance An ester of the fatty acid isostearic acid combined with polyethylene glycol and glycerin May be animal-derived or synthetic Commonly used as an emulsifier and mild cleansing agent Noted for offering skin-softening properties PEG-20 Glyceryl Triisostearate description PEG-20 glyceryl triisostearate is an ester of the fatty acid isostearic acid combined with polyethylene glycol and glycerine. It may be animal-derived or synthetic (Paula's Choice uses the latter). Its high molecular weight keeps it from penetrating past skin's surface. It has emollient and skin-softening properties as well as being an emulsifier and mild cleansing agent, where it's often seen in oil-based formulas due to its ability to help oily ingredients rinse from skin without leaving a greasy residue. This ingredient has undergone extensive toxicology review and is considered non-irritating and safe as used in rinse-off or leave-on cosmetics. Related ingredients: Glycerin Isostearic Acid Polyethylene Glycol