The present disclosure provides GIP receptor agonist peptide compounds having an activating action on GIP receptors and use of the GIP receptor agonist peptide as a medicament for the treatment and/or prevention of diabetes, obesity, emesis, or a symptom or condition associated with diabetes, obesity, or emesis. Specifically, a GIP receptor agonist peptide containing a sequence represented by the formula (I) or a salt thereof, and a medicament comprising the same are provided. Formula I: P1-A1-A2-A3-A4-A5-A6-A7-A8-A9-A10-A11-A12-A13-A14-A15-A16-A17-A18-A19-A20-A21-A22-A23-A24-A25-A26-A27-A28-A29-A30-A341-A32-A33-A34-A35-A36-A37-A38-A39-A40-A41-P2 (SEQ ID NO: 4), or a salt thereof, wherein each symbol is as defined herein, with the proviso that the GIP receptor agonist peptide does not have an amino acid sequence as provided in SEQ ID NOs: 4-569 disclosed in PCT/JP2018/013540.