The invention relates to peptides of formula (I) R-V.sup.1-Ala.sup.2-His.sup.3-X.sup.4-Y.sup.5-Trp.sup.5-NH2 wherein R represents a hydrogen atom or a protective group which can be chosen from among a benzoyl group, a tosyl group, a benzene sulfonyl group, a benzyloxycarbonyl group or a pyridinepropionyl group; V represents a natural amino acid or not chosen from among norleucine, norvaline and 2-N-Me-norleucine, X represents a natural amino acid or not having an aromatic character chosen from among phenylalanine, 1-naphtylalanine, 2-naphtylalanine, phenylglycine, benzothienylalanine, 4,4'-biphenylalanine, 3,3-diphenylalanine, homophenylalanine, indanylglycine, 4-methylphenylalanine, thienylalanine, p-nitrophenylalanine, halogenophenylalanine of configuration L or D; Y represents a natural amino acid of configuration L, having a basic character chosen from among arginine, lysine or ornithine, the enantiometers or diastercoisomers, and the mixtures thereof, including racemic mixtures. The invention also relates to a method for the preparation and application thereof in the field of therapeutics or cosmetics.