Non therapeutic cosmetic use of at least one dithiolane compound chosen from those corresponding to formula: in which: Y denotes O, NR 1 or S; R 1 denotes a hydrogen atom; a saturated linear C 1 -C 20 or branched C 3 -C 20 or unsaturated C 2 -C 20 alkyl hydrocarbon-based group; a phenyl group optionally substituted with one or more hydroxyls and/or with one or more C 1 -C 8 alkoxy radicals; R denotes a hydrogen atom; a saturated linear C 1 -C 20 or branched C 3 -C 20 or unsaturated C 2 -C 20 alkyl hydrocarbon-based group; a phenyl group optionally substituted with one or more hydroxyls and/or with one or more C 1 -C 8 alkoxy radicals; or a saturated C 1 -C 8 alkyl group containing a phenyl substituent optionally substituted with one or more hydroxyls and/or with one or more C 1 -C 8 alkoxy radicals; R optionally bears one or more substituents chosen from OR 2, SR 2, NR 2 R 3 and COOR 2 in which: R 2 denotes a hydrogen atom or a saturated linear C 1 -C 5 or branched C 3 -C 5 or unsaturated C 2 -C 5 hydrocarbon-based group, or a phenyl group; R 3 denotes a hydrogen atom; a saturated linear C 1 -C 5 or branched C 3 -C 5 or unsaturated C 2 -C 5 hydrocarbon-based group; a phenyl group; an acetyl group. When Y denotes NR 1, R and R 1 may form a ring chosen from pyrrolidine, pyrroline, piperazine, morpholine, thiomorpholine and azepine; m = 0 or 1 or 2; n = 0 or 1 or 2; and also the salts thereof, chelates thereof, solvates thereof and optical isomers thereof, in a composition comprising a physiologically acceptable medium, for the purpose of reinforcing and/or preserving the natural antioxidant protection of the skin against oxidative stress caused especially by UV radiation. Y denotes O, NR 1 or S; R 1 denotes a hydrogen atom; a saturated linear C 1 -C 20 or branched C 3 -C 20 or unsaturated C 2 -C 20 alkyl hydrocarbon-based group; a phenyl group optionally substituted with one or more hydroxyls and/or with one or more C 1 -C 8 alkoxy radicals; R denotes a hydrogen atom; a saturated linear C 1 -C 20 or branched C 3 -C 20 or unsaturated C 2 -C 20 alkyl hydrocarbon-based group; a phenyl group optionally substituted with one or more hydroxyls and/or with one or more C 1 -C 8 alkoxy radicals; or a saturated C 1 -C 8 alkyl group containing a phenyl substituent optionally substituted with one or more hydroxyls and/or with one or more C 1 -C 8 alkoxy radicals; R optionally bears one or more substituents chosen from OR 2, SR 2, NR 2 R 3 and COOR 2 in which: R 2 denotes a hydrogen atom or a saturated linear C 1 -C 5 or branched C 3 -C 5 or unsaturated C 2 -C 5 hydrocarbon-based group, or a phenyl group; R 3 denotes a hydrogen atom; a saturated linear C 1 -C 5 or branched C 3 -C 5 or unsaturated C 2 -C 5 hydrocarbon-based group; a phenyl group; an acetyl group. When Y denotes NR 1, R and R 1 may form a ring chosen from pyrrolidine, pyrroline, piperazine, morpholine, thiomorpholine and azepine; m = 0 or 1 or 2; n = 0 or 1 or 2; R 2 denotes a hydrogen atom or a saturated linear C 1 -C 5 or branched C 3 -C 5 or unsaturated C 2 -C 5 hydrocarbon-based group, or a phenyl group; R 3 denotes a hydrogen atom; a saturated linear C 1 -C 5 or branched C 3 -C 5 or unsaturated C 2 -C 5 hydrocarbon-based group; a phenyl group; an acetyl group. When Y denotes NR 1, R and R 1 may form a ring chosen from pyrrolidine, pyrroline, piperazine, morpholine, thiomorpholine and azepine; m = 0 or 1 or 2; n = 0 or 1 or 2;