The invention is directed to the use of at least one peptide of formula: X –(Xaa1 ) n –Pro* –(Xaa2)m –Y (I) With: -n = 0, 1 or 2； -m =0 or 1and if m = 0 then n ≠ 0 -Xaa is: -An hydrophobic aminoacid selected from Alanine (Ala, A), Valine (Val, V), Methionine (Met, M), Leucine (Leu, L), Isoleucine (Ile, I), Phenylalanine (Phe, F), Proline (Pro, P) and analogues and derivatives thereof； -A polar aminoacid selected from Serine (Ser, S), Threonine (Thr, T), Tyrosine (Tyr, Y), Asparagine (Asn, N), Glutamine (Gln, Q)and analogues and derivatives thereof； or -Glycine (Gly, G)； When n = 2 the two aminoacids Xaa1 can be the same or different； -Xaa2 is: -An hydrophobic aminoacid selected from Alanine (Ala, A), Valine (Val, V), Methionine (Met, M), Leucine (Leu, L), Isoleucine (Ile, I), Phenylalanine (Phe, F), Proline (Pro, P) and analogues and derivatives thereof； -A basic aminoacid selected from Arginine (Arg, R), Lysine (Lys, K) and Histidine (His, H) and analogues and derivatives thereof； -Glycine (Gly, G) or Serine (Ser, S)； -At the N terminal end of the peptide, X is selected from H, -CO-R1 and -SO2 -R1； -At the C terminal end of the peptide, Y is selected from OH, OR1, NH2, NHR1 or NR1 R2, -R1 and R2 being independantly from each other, selected from an alkyle, aryle, aralkyle, alkylaryl, alkoxy and aryloxy group, that can be linear, branched, cyclic, poly-cyclic, non- saturated, hydroxylated, carbonylated, phosphorylated and/or sulphured, with the possibility to have in said group skeleton a O, S and/or N heteroatom； -Pro* corresponding to a Proline, an analogue or derivative thereof； Excluding the peptides where X=H and Y=OH, for a non therapeutical cosmetic pro-pigmenting treatment of skin. The invention also encompasses new tripeptides of formula (I) suitable for a non therapeutical cosmetic treatment of skin.L'invention concerne l'utilisation d'au moins un peptide de formule : X -(Xaa1 )n -Pro* -(Xaa2)m -Y (I) ayant : -n = 0, 1 ou 2 ； -m = 0 ou 1 et si m = 0 alors
