A compound of general formula: R 1 -W n -X m -AA 1 -AA 2 -AA 3 -AA 4 -AA 5 -AA 6 -AA 7 -Y p -Z q -R 2 its stereoisomers, mixtures thereof and/or its cosmetically or pharmaceutically acceptable salts, characterized in that: AA 1 is selected from the group formed by -Arg-, -Lys-, -Gln-, -Asn-, -Glu- and -Asp-; AA 2 is selected from the group formed by -His-, -Gln-, -Asn-, -Glu- and -Asp-; AA 3 is selected from the group formed by -Leu and -Phe-; AA 4 is selected from the group formed by -Lys- and -Leu; AA 5 is selected from the group formed by -Arg-, -His-, -Lys-, -Gln-, -Asn-, -Glu- and -Asp-; AA 6 is -Trp-; AA 7 is selected from the group formed by -Met-, -MetO- and -MetO 2 -; W, X, Y, Z are amino acids and are independently selected from amongst themselves; n, m, p and q are independently selected from amongst themselves and have a value of 0 or 1; n+m+p+q is smaller or equal to 2; R 1 is selected from the group formed by H, a polymer derived from polyethylene glycol, a non-cyclic substituted or unsubstituted 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-, wherein R 5 is selected from the group formed by H, a non-cyclic substituted or unsubstituted aliphatic group, substituted or unsubstituted alicyclyl, substituted or unsubstituted aryl, substituted or unsubstituted aralkyl, substituted or unsubstituted heterocyclyl and substituted or unsubstituted heteroarylalkyl; R 2 is selected from the group formed by -NR 3 R 4, -OR 3 and -SR 3, wherein R 3 and R 4 are independently selected from the group formed by H, a polymer derived from polyethylene glycol, a non-cyclic substituted or unsubstituted aliphatic group, substituted or unsubstituted alicyclyl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted heteroarylalkyl, substituted or unsubstituted aryl, and substituted or unsubstituted aralkyl; and R 1 and R 2 are not α-amino acids. AA 1 is selected from the group formed by -Arg-, -Lys-, -Gln-, -Asn-, -Glu- and -Asp-; AA 2 is selected from the group formed by -His-, -Gln-, -Asn-, -Glu- and -Asp-; AA 3 is selected from the group formed by -Leu and -Phe-; AA 4 is selected from the group formed by -Lys- and -Leu; AA 5 is selected from the group formed by -Arg-, -His-, -Lys-, -Gln-, -Asn-, -Glu- and -Asp-; AA 6 is -Trp-; AA 7 is selected from the group formed by -Met-, -MetO- and -MetO 2 -; W, X, Y, Z are amino acids and are independently selected from amongst themselves; n, m, p and q are independently selected from amongst themselves and have a value of 0 or 1; n+m+p+q is smaller or equal to 2; R 1 is selected from the group formed by H, a polymer derived from polyethylene glycol, a non-cyclic substituted or unsubstituted 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-, wherein R 5 is selected from the group formed by H, a non-cyclic substituted or unsubstituted aliphatic group, substituted or unsubstituted alicyclyl, substituted or unsubstituted aryl, substituted or unsubstituted aralkyl, substituted or unsubstituted heterocyclyl and substituted or unsubstituted heteroarylalkyl; R 2 is selected from the group formed by -NR 3 R 4, -OR 3 and -SR 3, wherein R 3 and R 4 are independently selected from the group formed by H, a polymer derived from polyethylene glycol, a non-cyclic substituted or unsubstituted aliphatic group, substituted or unsubstituted alicyclyl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted heteroarylalkyl, substituted or unsubstituted aryl, and substituted or unsubstituted aralkyl; and R 1 and R 2 are not α-amino acids.