Non-therapeutic use of at least one compound of the formula where R1 stands for a straight-chain or branched C 1 - to C 20 -alkyl group, R2 stands for - H, R4 stands for - H, - straight-chain or branched C 1 - to C 20 -alkyl group or - straight-chain or branched C 2 - to C 20 -alkenyl group having one or more double bonds, R3 stands for a radical selected from - H, - straight-chain or branched C 1 - to C 20 -alkyl group, - straight-chain or branched C 2 - to C 20 -alkenyl group having one or more double bonds, where the alkenyl group may also be substituted by one or more saturated or unsaturated C 3 - to C 12 -cycloalkyl groups, - straight-chain or branched C 2 - to C 20 -alkynyl group having one or more triple bonds, - saturated or unsaturated C 3 - to C 12 -cycloalkyl group, where the rings may in each case also be bridged by -(CH 2) n - groups where n = 1 to 3, - an acyl radical of the formula -C(=O)-R6, R6 stands for - straight-chain or branched C 1 - to C 20 -alkyl group, - a radical of the formula in which X stands for straight-chain or branched C 1 - to C 6 alkylene or straight-chain or branched C 2 - to C 6 -alkenylene and the radicals R5 are selected, independently of one another, from H, OH, straight-chain or branched C 1 - to C 6 alkyl or straight-chain or branched O-(C 1 - to C 6 -alkyl), for the care, preservation or improvement of the general condition or appearance of the skin or hair. R1 stands for a straight-chain or branched C 1 - to C 20 -alkyl group, R2 stands for - H, - H, R4 stands for - H, - straight-chain or branched C 1 - to C 20 -alkyl group or - straight-chain or branched C 2 - to C 20 -alkenyl group having one or more double bonds, - H, - straight-chain or branched C 1 - to C 20 -alkyl group or - straight-chain or branched C 2 - to C 20 -alkenyl group having one or more double bonds, R3 stands for a radical selected from - H, - straight-chain or branched C 1 - to C 20 -alkyl group, - straight-chain or branched C 2 - to C 20 -alkenyl group having one or more double bonds, where the alkenyl group may also be substituted by one or more saturated or unsaturated C 3 - to C 12 -cycloalkyl groups, - straight-chain or branched C 2 - to C 20 -alkynyl group having one or more triple bonds, - saturated or unsaturated C 3 - to C 12 -cycloalkyl group, where the rings may in each case also be bridged by -(CH 2) n - groups where n = 1 to 3, - an acyl radical of the formula -C(=O)-R6, - H, - straight-chain or branched C 1 - to C 20 -alkyl group, - straight-chain or branched C 2 - to C 20 -alkenyl group having one or more double bonds, where the alkenyl group may also be substituted by one or more saturated or unsaturated C 3 - to C 12 -cycloalkyl groups, - straight-chain or branched C 2 - to C 20 -alkynyl group having one or more triple bonds, - saturated or unsaturated C 3 - to C 12 -cycloalkyl group, where the rings may in each case also be bridged by -(CH 2) n - groups where n = 1 to 3, - an acyl radical of the formula -C(=O)-R6, R6 stands for - straight-chain or branched C 1 - to C 20 -alkyl group, - a radical of the formula in which X stands for straight-chain or branched C 1 - to C 6 alkylene or straight-chain or branched C 2 - to C 6 -alkenylene and the radicals R5 are selected, independently of one another, from H, OH, straight-chain or branched C 1 - to C 6 alkyl or straight-chain or branched O-(C 1 - to C 6 -alkyl), - straight-chain or branched C 1 - to C 20 -alkyl group, - a radical of the formula in which X stands for straight-chain or branched C 1 - to C 6 alkylene or straight-chain or branched C 2 - to C 6 -alkenylene and the radicals R5 are selected, independently of one another, from H, OH, straight-chain or branched C 1 - to C 6 alkyl or straight-chain or branched O-(C 1 - to C 6 -alkyl), for the care, preservation or improvement of the general condition or appearance of the skin or hair.