Glucagon-like peptide-1 (GLP-1), an endogenous incretin hormone, is secreted by the gut in response to enteral nutrition and is responsible primarily for normal glucose homeostasis. There is a defective incretin effect in Type II diabetes mellitus such that meal-stimulated GLP-1 secretion is markedly impaired. However, a continuous infusion of exogenous GLP-1 can result in near normal insulin responses to a glucose load, suggesting preservation of insulinotropic activity. Liraglutide, a synthetic analogue that shares 97% structural homology to native GLP-1, is now a guideline-mandated antidiabetic therapy given as a once-daily subcutaneous injection.