There is a tremendous need to generate therapeutics targeting metabolic and gastrointestinal diseases. By targeting GPCRs, glucagon-like peptide (GLP-1 and GLP-2) receptors, therapeutics can be developed to address these globally prevalent medical disorders. In particular, engineered recombinant agonist analogues targeting the GLP-1 receptor are FDA approved for managing type 2 diabetes, obesity and body weight disorders, while GLP-2 analogues have been under therapeutic focus for the treatment of short bowel syndrome, a serious unmet medical disorder. Several other novel GLP analogues, including biosimilar and biobetters, are in clinical development; however, existing assays for characterising their mechanism-of-actions (MOAs) are complex and require extensive development time.