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, or 2; −m=0 or 1 and if m=0 then n≠0−Xaa is: —An hydrophobic aminoacid; —A polar aminoacid; or —Glycine (Gly, G); When n=2 the two aminoacids Xaa1 can be the same or different; —Xaa2 is: —An hydrophobic amino acid; —A basic aminoacid; —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; —Pro* Excluding the peptides where X=H and Y=OH, for a non therapeutical cosmetic pro-pigmenting treatment of skin.