The invention concerns a cosmetic or dermatological preparation with skin-lightening proteins. Said preparation has an efficient modified copper-binding protein content, the prosthetic group copper having been extracted by a prior exchange reaction or said proteins being produced by copper-free recombination. The suitable proteins are auracyanin, azurin, phytocyanin, plastocyanin, rusticyanin, ascorbate oxidase, ceruloplasmin, laccase, nitroreductase and copper-binding proteins such as Cu, Zn-superoxide dismutase, dioxygenase, monooxygenase, aminoxidase, diaminoxidase, cytochrome-c-oxidase, galactose oxidase, lysyl oxidase, cathecol oxidase, N2O-reductase, hemocyanin, tyrosinase, ubichinone oxidase, and mixtures thereof. The inventive preparation may contain other plant lightening agents.