It is the most widely used first-line oral medication for the treatment of type 2 diabetes mellitus (T2DM).
Indications (Approved Uses)
First-line treatment for type 2 diabetes – alone or combined with other antidiabetic drugs (e.g., sulfonylureas, SGLT2 inhibitors, insulin).
Off-label / adjunctive uses:
Polycystic Ovary Syndrome (PCOS) – to improve insulin resistance and restore ovulation
Prediabetes – in some cases to delay progression to T2DM
Occasionally investigated for weight management or cancer risk reduction (research stage)
Mechanism of Action:
Metformin does NOT increase insulin secretion, so it rarely causes hypoglycemia alone:
↓ Hepatic glucose production (suppresses gluconeogenesis via AMPK activation)
↑ Insulin sensitivity in peripheral tissues (muscle/fat)
↓ Intestinal glucose absorption
Slows gastric emptying slightly; may reduce appetite
