Cosmetic or dermatological preparations are comprised of from 0.01 to 5% by weight of a dicarboxylic acid selected from the group consisting of 8-hexadecene-1,16-dicarboxylic acid decanedioic acid nonanedioic acid and combinations thereof and from 0.01 to 5% by weight of ascorbic acid, salts of ascorbic acid, ascorbic acid derivatives and combinations thereof. These preparations provide skin-lightening and/or hair-lightening preparations which inhibit melanin biosynthesis and do not damage hair and/or skin.