Use of at least one compound of formula I ** ** Formula wherein R1 and R2 each independently represent aryl, alkyl group straight or branched chain of 1 to 30 carbon atoms which may be substituted with aryl or a group alkenyl straight or branched chain of 2 to 30 carbon atoms, containing one or more double bonds which may be substituted with aryl, wherein or R1 or R2 may represent H, wherein R1 and R2 together may also form a five- membered unsubstituted or substituted, which may be substituted a) with at least one alkyl group of straight or branched chain 1 to 30 carbon atoms and / or b) with at least one aryl group of 6 to 12 carbon atoms and / or c) with at least one alkenyl group linear or branched chain of 2 to 30 carbon atoms containing one or more double bonds, wherein the alkyl group of 1 to 30 carbon atoms and / or alkenyl group of 1 to 30 carbon atoms C may be substituted with aryl and / or aryl group of 6 to 12 C atoms p ou be substituted with alkyl, OH, O, NH2, NH-alkyl, N (alkyl) 2, C (O) alkyl, OC (O) alkyl and / or C (O) -Oalkyl, R3 represents H or an alkyl group straight or branched chain of 1 to 30 carbon atoms and R4 represents H or OR3, wherein aryl represents an aryl group of 6 to 12 carbon atoms which optionally may be substituted with alkyl, OH, O, NH2, NH-alkyl, N (alkyl) 2, C (O) alkyl, OC (O) alkyl or C (O) -Oalkyl, and alkyl denotes a straight or branched chain of 1 to 30 carbon atoms, and / or its salts, tautomers, stereoisomers and / or solvates, including mixtures thereof in all proportions as self-tanning substance.Uso de al menos un compuesto de fórmula I**Fórmula** donde R1 y R2 cada uno independientemente entre sí representan arilo, un grupo alquilo de cadena lineal o ramificada de 1 a 30 átomos de C que puede estar sustituido con arilo o un grupo alquenilo de cadena lineal o ramificada de 2 a 30 átomos de C, que contiene uno o varios enlaces dobles, que puede estar sustituido con arilo, donde o R1 o R2 puede representar H, donde R1
