The invention relates to a specific polyurethane urea, which can be obtained by reacting a single polyisocyanate component, at least one polymeric polyol component, at least one hydrophilizing component and a single amino-functional chain extender component, wherein the polyisocyanate component comprises more than 75 mol % isophorone diisocyanate and the amino-functional chain extender component comprises more than 75 mol % isophorone diamine. Said polyurethane urea can be used in the field of hair cosmetics, in particular in the form of a mixture with conventional solvents. The invention further relates to the use of the polyurethane urea in cosmetics, to a cosmetic composition containing the polyurethane urea, to the use of the cosmetic composition in cosmetics, and to a method for forming hair styles using the cosmetic composition.