The present invention provides a novel peptide compound having an activating action on GLP-1 receptors and GIP receptors and use of the peptide compound as a medicament. Specifically, a peptide containing a partial sequence represented by the formula (I) or a salt thereof and a medicament comprising the same are provided.P1-Tyr-Aib-Glu-Gly-Thr-αMePhe-Thr-Ser-Asp-Tyr-A11-A12-A13-Leu-Asp-A16-A17-Ala-Gln-A20-Glu-Phe-Val-Lys-Trp-Leu-Leu-Lys-A29 (I) wherein each symbol is as defined herein.本發明提供一種具有活化GLP-1受體及GIP受體作用之新穎胜肽化合物，及該胜肽化合物作為藥物之用途。特別是提供含有式(I)所示之部分序列之胜肽或其鹽及包括該胜肽或其鹽之藥物：P1-Tyr-Aib-Glu-Gly-Thr-α MePhe-Thr-Ser-Asp-Tyr-A11-A12-A13-Leu-Asp-A16-A17-Ala-Gln-A20-Glu-Phe-Val-Lys-Trp-Leu-Leu-Lys-A29 (I)其中，各符號係如本文中所定義。
