Learning About Metformin for Type 2 Diabetes

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Metformin is a medicine used to treat type 2 diabetes. It helps keep blood sugar levels on target.

You may have tried to eat a healthy diet, lose weight, and get more exercise to keep your blood sugar in your target range. If those things do not help, you may take a medicine called metformin. It helps your body use insulin. This can help you control your blood sugar. You might take it on its own or with other medicines.

When taken on its own, metformin should not cause low blood sugar or weight gain.


  • Metformin (Glucophage)

Possible side effects

Common side effects include:

  • Short-term nausea.
  • Not feeling hungry.
  • Diarrhea.
  • Increased gas in your belly.
  • A metallic taste.

You may have side effects or reactions not listed here. Check the information that comes with your medicine.

What to know about taking this medicine

  • Metformin does not usually cause low blood sugar. But you may get a low blood sugar when you take metformin and you exercise hard, drink alcohol, or you do not eat enough food.
  • Sometimes metformin is combined with other diabetes medicine. Some of these can cause low blood sugar.
  • If you need a test that uses a dye or you need to have surgery, be sure to tell all of your doctors that you take metformin. You may have to stop taking it before and after the test or surgery.
  • Over time, blood levels of vitamin B12 can decrease in some people who take metformin. Your body needs this B vitamin to make blood cells. It also keeps your nervous system healthy. If you have been taking metformin for more than a few years, ask your doctor if you need a B12 blood test to measure the amount of vitamin B12 in your blood.
  • Be safe with medicines. Take your medicines exactly as prescribed. Call your doctor if you think you are having a problem with your medicine.
  • Check with your doctor or pharmacist before you use any other medicines. This includes over-the-counter medicines. Make sure your doctor knows all of the medicines, vitamins, herbal products, and supplements you take. Taking some medicines together can cause problems.

Where can you learn more?

Go to http://www.healthwise.net/patientEd

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