Metformin: what it treats, how to take it, and simple safety tips
Metformin is one of the most commonly prescribed medicines for type 2 diabetes. It lowers blood sugar mainly by reducing how much glucose the liver releases and by improving the body's response to insulin. People also use metformin for polycystic ovary syndrome (PCOS) and, in some cases, for weight support when recommended by a doctor.
How metformin works and common uses
Metformin comes in two main forms: immediate-release (taken two or three times daily) and extended-release (once daily). Typical starting doses are 500 mg once or twice daily, usually with food to cut stomach upset. Doctors often increase the dose slowly up to 2,000–2,500 mg per day depending on the product and how well a person tolerates it.
Besides lowering A1c and fasting glucose, metformin often helps with modest weight loss or weight stability, and it rarely causes low blood sugar on its own. For PCOS, metformin can improve menstrual regularity and insulin-related symptoms, but you should only use it under a healthcare plan that monitors progress.
Side effects, safety checks, and practical tips
Most people get mild gastrointestinal issues at first—nausea, diarrhea, bloating. Those often improve after a few weeks. To reduce them: start on a low dose, take metformin with meals, and consider switching to the extended-release form if side effects persist.
Lactic acidosis is a rare but serious risk. It's more likely if you have severely reduced kidney function, severe dehydration, serious infection, or heavy alcohol use. Before you start metformin and during treatment, your provider should check kidney function (eGFR). Many clinicians stop metformin around the time of major surgery or certain contrast dye procedures — follow your doctor’s instructions.
Other practical checks: ask your doctor about measuring vitamin B12 after long-term use (metformin can lower B12 in some people). Keep a list of all your medicines—metformin can interact with drugs that affect kidneys or fluid balance. If you plan pregnancy or are pregnant, talk to your OB; metformin is sometimes used in pregnancy, but that decision needs medical input.
Cost and access tips: generic metformin is inexpensive. If GI side effects bother you, ask about the extended-release version or slower dose increases. Use medication reminders or a pillbox to keep doses consistent; consistent timing helps control blood sugar and makes monitoring easier.
When to call your doctor: severe stomach pain, persistent vomiting or diarrhea, shortness of breath, extreme tiredness, or any sign of dehydration. Also check in if your kidney test results change or you need imaging with contrast dye.
Metformin works well for many people, but safe use depends on proper monitoring and simple habits—start low, take with food, keep hydrated, and get regular blood tests. If you have questions about your dose or side effects, bring them up with your provider so you can use metformin safely and effectively.
