GIPR antagonism via peptide 7 reduces GIP but not GLP-1 stimulated insulin secretion from islets from human donors. Insulin secretion from islets from two human donors (A, R449 and B, R451) was measured in response to glucose, GIP, and GLP-1 ± 7 as indicated. The area under the curve (AUC) for glucose (C, D; 8–24 m), GIP (E, F; 44–62 m), and GLP-1 (G, H; 78–96 m) stimulated insulin secretion is recorded for each individual donor. Data represent mean ± SEM for 4 technical replicates per donor.