The present invention relates to a cosmetic method for preventing and treating skin aging comprising applying a composition containing S-acyl glutathione derivative in a dermatologically acceptable carrier to skin tissue. The acyl group is a saturated or unsaturated aliphatic C12-C24 group, preferably an unsaturated C16- C24 group, most preferably an unsaturated C18 group. In particularly preferred embodiments, the acyl group is a linoleoyl group.