The invention relates to the oral or nutraceutical cosmetic use of an effective amount of at least one monounsaturated fatty acid, a salt thereof and/or an ester thereof, as an active agent for treating and/or preventing skin complexion imperfections.USO COSMETICO DE COMPOSICIONES QUE COMPRENDEN ACIDO PETROSELINICO Y OTROS PRINCIPIOS ACTIVOS PARA TRATAR Y/O PREVENIR IMPERFECCIONES DEL COLOR DE LA PIEL.