The use of copolymers obtainable by the radically initiated polymerization of A) 50 to 99.9 wt % of an olefinically unsaturated C3 to C5 monocarboxylic acid, an olefinically unsaturated C4 to C8 dicarboxylic acid or its anhydride, or a mixture of such carboxylic acids or carboxylic acid anhydrides with B) 0.1 to 50 wt % of one or more long-chained compounds with isolated multiple C—C bonds from the group (1) mono or polyunsaturated C8 to C30 monocarboxylic acids which may have additional hydroxyl groups and their alkaline metal and earth alkaline metal salts, alkyl esters, amides, sorbitane esters, glycerin esters and polyglycerin esters, (2) mono or polyunsaturated aliphatic Ca to C30 amines, (3) mono or polyunsaturated C8 to C30 alcohols and esters thereof with saturated Cl to C4 monocarboxylic acids, (4) to (C8 to C30 alkyl) vinyl ether which may incorporate up to 25 alkylene oxide units, and (5) final and medium-position Ci3 to C30 alkenes; C) 0 to 49.9 wt % of other copolymerizable monomers, and D) 0 to 10 wt % of one or more compounds with at least two olefinically unsaturated groups in the molecule as cross-linking agents, as thickening or dispersing agents, especially in cosmetic and pharmaceutical preparations.