PROBLEM TO BE SOLVED: To provide a preventive or therapeutic agent for obesity, having excellent drug efficacy even in a usual administration form such as peripheral administration.SOLUTION: There is provided: a peptide derivative selected from the group consisting of PEG20k(AL)-β-Ala-Tyr-Nal(1)-Leu-Phe-Arg-Pro-Arg-Asn-NH2, PEG20k(AL)-β-Ala-Tyr-Nal(2)-Leu-Phe-Arg-Pro-Arg-Asn-NH2, PEG20k(AL)-NpipAc-Tyr-Nal(2)-Leu-Phe-Arg-Pro-Arg-Asn-NH2, PEG20k(AL)-NpipAc-Tyr-Nal(2)-Leu-Phe-Arg-Ala-Arg-Asn-NH2, PEG20k(AL)-PEG(2)-Tyr-Nal(2)-Leu-Phe-Arg-NMeAla-Arg-Asn-NH2 and the like or its salt.COPYRIGHT: (C)2014,JPO&INPIT【課題】末梢投与等の通常の投与形態でも優れた薬効を有する肥満症の予防または治療剤等の提供。【解決手段】PEG20k(AL)-β-Ala-Tyr-Nal(1)-Leu-Phe-Arg-Pro-Arg-Asn-NH2、PEG20k(AL)-β-Ala-Tyr-Nal(2)-Leu-Phe-Arg-Pro-Arg-Asn-NH2、PEG20k(AL)-NpipAc-Tyr-Nal(2)-Leu-Phe-Arg-Pro-Arg-Asn-NH2、PEG20k(AL)-NpipAc-Tyr-Nal(2)-Leu-Phe-Arg-Ala-Arg-Asn-NH2、PEG20k(AL)-PEG(2)-Tyr-Nal(2)-Leu-Phe-Arg-NMeAla-Arg-Asn-NH2等からなる群から選ばれるペプチド誘導体またはその塩。【選択図】なし
