If you have type 2 diabetes, you’ve probably heard of metformin. It’s the medication doctors typically prescribe first when you’re diagnosed.
Metformin is a tablet that lowers blood sugar levels by keeping your liver from releasing too much sugar, also called glucose, into your blood. It also makes your body more sensitive to insulin -- the hormone that controls your blood sugar. Metformin makes the cells in your muscles, fat, and liver react to insulin more efficiently so they can better absorb glucose from your blood.
There are a few reasons why metformin is the typical first choice for diabetes treatment. It’s unlikely to make your blood sugar dip too low the way other medicines can. And it doesn’t cause weight gain. Some people even lose a little bit of weight when they take metformin.
Doctors prescribe this medicine when a healthy diet and exercise routine aren’t doing enough to keep blood sugar levels under control. It may be the only medication you take for diabetes, or you may need others, too. But it’s likely not a good option if you have:
- Liver or kidney problems
- A bad infection
- Heart failure or had a recent heart attack
- An allergy to the medication
Metformin has some common side effects, including:
- Loss of appetite
- Metallic taste in your mouth
You can ease these problems if you take the medicine with food or if your doctor starts you at a low dose of the medicine and gradually raises it. For many people, side effects go away after a few weeks as your body gets used to the medicine.
Some people will have more serious side effects, like a vitamin B12 deficiency. If you take metformin along with another diabetes medicines, your blood sugar levels could drop too low, a condition called hypoglycemia. Metformin can also cause a serious condition called lactic acidosis, when too much lactic acid builds up in your body. But this is very rare, and it usually affects people who have another serious health problem, like kidney failure, liver disease, or heart failure. But if you notice any of the signs -- stomach pain, low appetite, diarrhea, fast breathing, muscle cramps, weakness, or tiredness -- call your doctor right away.