Positive allosteric modulator (PAM) at the glucagon-like peptide 1 receptor (GLP-1; EC50 value 0.66 μM) with good selectivity over GLP-2, GIP, PTH, and glucagon receptors. BETP has a signifficant effect on cAMP accumulation, iCa2+ mobilization, and β-arrestin1 and β-arrestin2 recruitment in Flp-In-CHO cells stably expressing the human GLP-1R (pEC50 values 5.2, 5, 5.0, and 5.0, respectively). BETP induced glucose-dependent insulin secretion in vitro and in vivo, and increased calcium influx in CHO cells expressing GLP-1R.