Fig. 2. Classification of currently available glucagon-like peptide-1 receptor agonists (GLP-1 RAs) by structure and duration of action. Adapted from Kuritzky et al. [26], with permission from Taylor & Francis. QW, weekly; QD, daily; BID, twice a day; DPP-4, dipeptidyl peptidase 4; IgG4, immunoglobulin G4.