Which statement accurately describes the primary mechanism of action of metformin?

Which statement accurately describes the primary mechanism of action of metformin?

• A. Stimulates insulin secretion
• B. Decreases hepatic glucose production
• C. Inhibits SGLT2
• D. Increases intestinal glucose absorption

Answer: (B)

Metformin’s main effect is to lower glucose by reducing the liver’s production of glucose, especially gluconeogenesis. It activates AMPK in liver cells, which shifts metabolism away from generating glucose and toward more balanced energy use. This hepatic glucose output reduction drops fasting and postprandial glucose levels, improving overall glycemic control without stimulating insulin secretion. Other effects, like modest changes in intestinal glucose handling or improved peripheral insulin sensitivity, exist but are secondary to the liver-focused action. In contrast, increasing insulin release is the action of other drug classes, and inhibiting SGLT2 or increasing intestinal glucose absorption would not align with metformin’s primary mechanism.

Metformin’s main effect is to lower glucose by reducing the liver’s production of glucose, especially gluconeogenesis. It activates AMPK in liver cells, which shifts metabolism away from generating glucose and toward more balanced energy use. This hepatic glucose output reduction drops fasting and postprandial glucose levels, improving overall glycemic control without stimulating insulin secretion. Other effects, like modest changes in intestinal glucose handling or improved peripheral insulin sensitivity, exist but are secondary to the liver-focused action. In contrast, increasing insulin release is the action of other drug classes, and inhibiting SGLT2 or increasing intestinal glucose absorption would not align with metformin’s primary mechanism.