The object of the present invention relates to a novel family of peptide conjugates of formula (I): A-X1-X2-Pro-Ala-X—B  (I) wherein: A represents a hydrogen atom, a C6 to C20 acyl group or a cholesterol residue; X1 represents a covalent bond, an alanine or a proline; X2 represents an arginine, a lysine, or an alanine; X represents a lysine, an alanine, or a phenylalanine; and B represents a hydroxyl or an amine; or one of its preferentially pharmaceutically, dermatologically or cosmetically acceptable salts, as well as their synthesis processes and their uses for reducing hair loss and stimulating hair growth.