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 1 and if m=0 then n≠；0 -Xaa1 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 NR1R2, R1 and R2 being independently 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.
