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-Xaai is: —An hydrophobic amino acid; —A polar amino acid; —or Glycine (Gly, G); When n=2 the two amino acids Xaa1 can be the same or different; —Xaa2 is: —An hydrophobic amino acid; —A basic amino acid 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; Excluding the peptides where X=H and Y=OH, for a non therapeutical cosmetic pro-pigmenting treatment of skin.