GCGR Antagonist 2, a Furan-2-carbohydrazide, serves as an orally active antagonist of the glucagon receptor. It exhibits affinity for the human glucagon receptor (hGluR) with a dissociation constant (Kd) of 2.3 nM and demonstrates inhibitory activity against the rat receptor with a half-maximal inhibitory concentration (IC50) of 0.43 nM. Additionally, this compound effectively prevents glucagon-stimulated glycogenolysis.