Peptide derivatives of glucagon-like peptide-1 (GLP-1), exendin-3 and exendin-4 which are modified with an amine at the C terminus and bind to GLP-1 receptor through the N terminus, are new. An independent claim is also included for chimeric peptides comprising the GLP-1(1-37) sequence of formula (I) and either the exendin-3 sequence of formula (II) or the exendin-4 sequence of formula (III): H-His-Asp-Glu-Phe-Glu-Arg-His-Ala-Glu-Gly-Thr-Phe-Thr-Ser-Asp-Val-Ser-Ser-Tyr-Leu-Glu-Gly-Gln-Ala-Ala-Lys-Glu-Phe-Ile-Ala-Trp-Leu-Val-Lys-Gly-Arg-Gly-OH (I) H-His-Ser-Asp-Gly-Thr-Phe-Thr-Ser-Asp-Leu-Ser-Lys-Gln-Met-Glu-Glu-Glu-Ala-Val-Arg-Leu-Phe-Ile-Glu-Trp-Leu-Lys-Asn-Gly-Gly-Pro-Ser-Ser-Gly-Ala-Pro-Pro-Pro-Ser-NH 2 (II) H-His-Gly-Glu-Gly-Thr-Phe-Thr-Ser-Asp-Leu-Ser-Lys-Gln-Met-Glu-Glu-Glu-Ala-Val-Arg-Leu-Phe-Ile-Glu-Trp-Leu-Lys-Asn-Gly-Gly-Pro-Ser-Ser-Gly-Ala-Pro-Pro-Pro-Ser-NH 2 (III) ACTIVITY : Cytostatic. MECHANISM OF ACTION : GLP-1 receptor ligand.본 발명은 GLP-1 수용체에 결합하는 GLP-1(글루카곤-유사 펩티드 1) 및 엑센딘-3 및/또는 엑센딘-4로부터 유도된 펩티드에 관한 것이며, 이는 GLP-1 수용체 발현이 역할하는 양성 및 악성 질환들을 진단하고 치료하는 수단을 제조하기 위하여 표지되거나 비표지되어 사용될 수 있다.