Which hormone lowers blood glucose after a meal?

• A. Glucagon
• B. Insulin
• C. Epinephrine
• D. Cortisol

Answer: (B)

After a meal, blood glucose rises and triggers insulin release from pancreatic beta cells. Insulin lowers blood glucose by promoting entry of glucose into liver, muscle, and adipose tissue, especially through GLUT4 transporters in muscle and fat. It also drives glucose storage as glycogen in the liver and muscles (glycogenesis) and enhances glycolysis, while suppressing hepatic glucose production by inhibiting gluconeogenesis and glycogenolysis. In this way, insulin shifts metabolism toward storage and utilization of the incoming glucose, bringing blood sugar back toward normal. The other hormones mentioned (glucagon, epinephrine, and cortisol) tend to raise blood glucose by stimulating glucose production in the liver, so insulin is the key hormone that lowers glucose after a meal.