GIP(3-42) is a truncated form of Glucose-dependent Insulinotropic Polypeptide (GIP), functioning primarily as a competitive antagonist or weak partial agonist at the GIP receptor. Its main application lies in research settings, particularly in studies related to glucose metabolism and insulin secretion. Scientists use GIP(3-42) to investigate the role of endogenous GIP by selectively blocking its receptor activity, helping to clarify the hormone’s contribution to the incretin effect. It is also employed in metabolic research to explore conditions such as type 2 diabetes and obesity. By inhibiting full-length GIP action, researchers can assess changes in insulin response, glucose tolerance, and energy balance. Additionally, GIP(3-42) supports studies examining the interaction between GIP and GLP-1 pathways, which is relevant for developing dual or multi-receptor agonist therapies for metabolic disorders. Due to its specific mode of action, it serves as a valuable tool for dissecting receptor-specific effects in cell cultures and animal models.