INS and type 2 diabetes mellitus: Although all GLP-1R agonists are effective in stabilizing blood glucose levels, glycated hemoglobin (HbA1c), cholesterol levels, insulin sensitivity, and several other beneficial aspects of metabolism in T2D patients (Courrèges et al., 2008; Patel et al., 2014; Jinnouchi et al., 2015; Rizvi et al., 2015; Rizzo et al., 2015, 2016), drug administration has been challenging.