About Metformin
Metformin is a biguanide oral medication and the most widely prescribed drug for type 2 diabetes worldwide. Available as an affordable generic since the 1990s, it has been a cornerstone of type 2 diabetes management for decades and is recommended as first-line therapy by the American Diabetes Association (ADA), the American Association of Clinical Endocrinologists, and most international diabetes guidelines. Beyond blood sugar control, metformin has shown benefits for weight management (weight-neutral to modest weight loss), cardiovascular outcomes, and has been studied for potential roles in cancer prevention and longevity. It comes in regular and extended-release (XR) formulations.
How It Works
Metformin primarily works by reducing glucose production in the liver (hepatic gluconeogenesis), which is often elevated in type 2 diabetes. It also improves the sensitivity of muscle and fat cells to insulin (insulin sensitization), allowing more glucose to enter cells rather than accumulating in the bloodstream. Unlike some diabetes medications, metformin does not stimulate insulin secretion, which means it does not cause hypoglycemia (low blood sugar) when used alone.
Key Facts
- ✓First-line medication for type 2 diabetes per ADA guidelines
- ✓Very affordable generic — often under $10/month
- ✓Does not cause hypoglycemia when used alone
- ✓Weight-neutral or modest weight loss effect
- ✓Must be stopped before contrast dye procedures (CT scans)
- ✓Available in regular and extended-release formulations
Who Is Metformin For?
Metformin is the standard first-line medication for most newly diagnosed type 2 diabetes patients, particularly those who are overweight or obese. It is also used for prediabetes and polycystic ovary syndrome (PCOS). It is not appropriate for people with severe kidney disease (eGFR <30), liver disease, or conditions that increase lactic acidosis risk. It should be used cautiously in people over 65 and those with heart failure.
Snapshot
Cost
Estimated monthly cost:
Medical Disclaimer: This information is for educational purposes only and should not be used as a substitute for professional medical advice. Always consult your healthcare provider before starting, stopping, or changing any medication. Prices shown are estimates and may vary by location and pharmacy.