The invention relates to a compound of formula (I) R1 - Wm-Xn-AAi - AA2-AA3-AA4-AA5-AA6- Yp-Zq-Ra, a stereoisomer and/or cosmetically acceptable salt thereof wherein: AA1 is Asp, Gly, Asn, Gln, Ala or no amino acid; AA2 is Val, Ile, Leu or Ala; AA3 is Tyr, Phe, Trp, Lys, Arg or His; AA4 is Lys, Arg, His, Pro or Val; AA5 is Asn, Asp, Gln or no amino acid; AA6 is Thr, Ala, Ser or no amino acid. The compounds are useful for the treatment and/or prevention of the symptoms of skin aging and, in particular, for the treatment and/or prevention of skin wrinkles, the treatment and/or prevention of a sagging appearance of the skin, and/or the reduction and/or prevention of facial asymmetry.