A compound – derivative of metastin selected from (1): Ac-D-Tyr-Hyp-Alb-Thr-Cha-Gly((E)CH=CH)Leu-Arg(Me)-Trp-NH2, Ac-D-Tyr-Hyp-Asn-Thr-Cha-Gly((E)CH=CH)Leu-Arg-Trp-NH2 and Ac-D-Tyr-Hyp-Alb-Thr-Cha-Gly((E)CH=CH)Leu-Arg-Trp-NH2 (1) or salt thereof, medicament containing it and use of the compound and the medicament for supressing a cancer metastasis or cancer growth, for supressing gonadotropic hormone or sex hormone secretion, for treatment of infertility, endometriosis and pubertas precox or hysteromyoma.