An incretin hormone; induces insulin secretion in response to glucose; a GIP receptor agonist (IC50 = 3.2 nM; EC50 = 377 pM); stimulates insulin secretion from BRIN-BD11 rat pancreatic β-cells at 10 nM; decreases blood glucose level and increases plasma insulin level in rats following glucose challenge at 1 pmol/min per 100 g; decreases plasma glucose level and increases insulin level in ob/ob mice following glucose challenge at 25 nmol/kg ,