Trihydroxystearin Bon Émollient Hydratation Trihydroxystearin at a glance Mix of glycerine and fatty acid hydroxystearic acid (which is derived from castor oil) Used in amounts between 1-7% as an occlusive or thickener in cosmetics Ruled safe as used in skin care, hair care, and makeup products Also used as a direct and indirect food additive Trihydroxystearin description Trihydroxystearin is a mixture of glycerine and castor oil-derived fatty acid (hydroxystearic acid). It is used in amounts between 1–7% as an emollient (moisturising ingredient) and texture-improving thickening agent in cosmetics. In particular, it helps thicken the oil (lipid) part of a skin care or makeup product. The independent Cosmetic Ingredient Review board has ruled that trihydroxystearin is safe as it is used in cosmetics. In addition to its use in makeup and skin care, the United States Food and Drug Administration has approved the use of trihydroxystearin as an indirect food additive, for example, as a component of paper or paperboard that comes in contact with aqueous or fatty foods. It is also used directly as a thickener for peanut butter. Related ingredients: Glycerin