Which medication listed is a GLP-1 receptor agonist used to treat type 2 diabetes mellitus?

• A. Januvia
• B. Byetta
• C. Metformin
• D. Invokana

Answer: (B)

GLP-1 receptor agonists imitate the incretin hormone GLP-1, boosting glucose-dependent insulin secretion, suppressing glucagon when glucose is high, and slowing gastric emptying to help lower blood sugar and often promote weight loss. Byetta is exenatide, a GLP-1 receptor agonist used to treat type 2 diabetes. The other drugs shown belong to different classes: Januvia is a DPP-4 inhibitor that increases endogenous GLP-1 levels by preventing its breakdown, Metformin is a biguanide that decreases hepatic glucose production and improves insulin sensitivity, and Invokana is an SGLT2 inhibitor that reduces glucose reabsorption in the kidneys.