Glycereth-26 Good Texture enhancer Hydration Glycereth-26 at a glance Synthetic, glycerin-based ingredient Used as a moisturising and thickening ingredient in cosmetics Is used in concentrations up to 39.5% in rinse-off products and 6% in leave-on formulas Ruled safe as used in cosmetics Glycereth-26 description Glycereth-26 is a synthetic glycerin-based ingredient used as a humectant (moisture-binding agent) and thickener in cosmetics. In its raw form it is a slightly viscous liquid. Glycereth-26 is used in rinse-off products in concentrations up to 39.5% and leave-on products in amounts up to 6%. The independent Cosmetic Ingredient Review panel has deemed glycereth-26 safe as it is used in cosmetics.