The invention relates to a tripeptide conjugate having general formula I, A-AA1-AA2-AA3-NH2, wherein A represents the radical corresponding to a monocarboxylic acid with general formula II, HOOC&mdashR, in which: R represents a linear or branched aliphatic radical at C1-C24, which is optionally substituted by a hydroxyl group and which can comprise one or more unsaturations, preferably between 1 and 6 unsaturations, lipoic acid or the reduced form thereof, dihydrolipoic acid, N-lipoyllysine, or phenylbutyric acid and AA1, AA2 and AA3, which may be identical or different, represent independently of each other an amino acid selected from His, Phe, Ala, Arg, Lys, Orn, Trp, Nap, Tpi and Tic, on the condition that at least one of AA1, AA2 or AA3 represent Phe, preferably Dphe in the form of enantiomers or diastereoisomers and mixtures thereof, including racemic mixtures.
