What should I know about metformin before taking it?

Donna Hill Howes, RN
Family Practitioner

Your doctor will need to test your kidney function before starting treatment.

Patients who take metformin should avoid alcohol.

If you are pregnant, planning to become pregnant, or may be pregnant, metformin may not be a good option for you. It is not known if it is safe for pregnant women.

If you are breastfeeding, metformin may not be a good option for you. It is not known if this drug can be is passed into breast milk.

If you have unstable heart failure, you should not take metformin. Once your heart failure is stable, metformin can be taken as long as kidney function is normal.

Metformin can cause a buildup of lactic acid in the blood (lactic acidosis) if there is kidney impairment. If you have abnormally high serum creatinine, you should not take metformin. 

This answer was adapted from Sharecare's award-winning AskMD app. Start a consultation now to find out what's causing your symptoms, learn how to manage a condition, or find a doctor.

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