A peptide of general formula R 1 -W p -X n -AA 1 -AA 2 -AA 3 -AA 4 -Y m -R 2 its stereoisomers, mixtures thereof, and/or its cosmetically or pharmaceutically acceptable salts, characterized in that at least one of the amino acids AA 1, AA 2 and AA 4 is uncoded, and in that: AA 1 is selected from the group consisting of -Arg-, -Phg- and -Nle- or is a bond; AA 2 is selected from the group consisting of -Ala-, -Phg-, -Cit- and -Nle-; AA 3 is selected from the group consisting of -Trp-, -Val- and -Tyr-; AA 4 is selected from the group consisting of -Phg- and -Gly-; W, X and Y are independently selected from the group consisting of coded or uncoded amino acids; p, n and m range between 0 and 1; R 1 is selected from the group consisting of H, substituted or unsubstituted non-cyclic aliphatic group, substituted or unsubstituted alicyclyl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted heteroarylalkyl, substituted or unsubstituted aryl, substituted or unsubstituted aralkyl and R 5 -CO; R 2 is selected from the group consisting of -NR 3 R 4, -OR 3 and -SR 3; wherein R 3 and R 4 are independently selected from the group consisting of H, substituted or unsubstituted non-cyclic aliphatic group, substituted or unsubstituted alicyclyl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted heteroarylalkyl, substituted or unsubstituted aryl and substituted or unsubstituted aralkyl; wherein R 5 is selected from the group consisting of H, substituted or unsubstituted non-cyclic aliphatic group, substituted or unsubstituted alicyclyl, substituted or unsubstituted aryl, substituted or unsubstituted aralkyl, substituted or unsubstituted heterocyclyl and substituted or unsubstituted heteroarylalkyl; and provided that when AA 1 is a bond, AA 2 is -Phg- and AA 3 is -Trp-. AA 1 is selected from the group consisting of -Arg-, -Phg- and -Nle- or is a bond; AA 2 is selected from the group consisting of -Ala-, -Phg-, -Cit- and -Nle-; AA 3 is selected from the group consisting of -Trp-, -Val- and -Tyr-; AA 4 is selected from the group consisting of -Phg- and -Gly-; W, X and Y are independently selected from the group consisting of coded or uncoded amino acids; p, n and m range between 0 and 1; R 1 is selected from the group consisting of H, substituted or unsubstituted non-cyclic aliphatic group, substituted or unsubstituted alicyclyl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted heteroarylalkyl, substituted or unsubstituted aryl, substituted or unsubstituted aralkyl and R 5 -CO; R 2 is selected from the group consisting of -NR 3 R 4, -OR 3 and -SR 3; wherein R 3 and R 4 are independently selected from the group consisting of H, substituted or unsubstituted non-cyclic aliphatic group, substituted or unsubstituted alicyclyl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted heteroarylalkyl, substituted or unsubstituted aryl and substituted or unsubstituted aralkyl; wherein R 5 is selected from the group consisting of H, substituted or unsubstituted non-cyclic aliphatic group, substituted or unsubstituted alicyclyl, substituted or unsubstituted aryl, substituted or unsubstituted aralkyl, substituted or unsubstituted heterocyclyl and substituted or unsubstituted heteroarylalkyl; and provided that when AA 1 is a bond, AA 2 is -Phg- and AA 3 is -Trp-.