What Is Metformin Used For? Uses, Conditions and How It Works

Quick Answer

Metformin is a prescription medication primarily used to treat type 2 diabetes in adults and children aged 10 and older. It helps control blood sugar levels by reducing the amount of glucose the liver produces, slowing sugar absorption from food, and improving how the body responds to insulin. It is usually the first medication doctors prescribe when diet and exercise alone are not enough to manage blood sugar.

What Is Metformin?

Metformin is a prescription medication that belongs to a class of drugs called biguanides. It has been used to treat type 2 diabetes for several decades and remains one of the most commonly prescribed medications worldwide.

Metformin is available as both an immediate-release tablet and an extended-release tablet, taken by mouth once or twice daily with meals.

What Is Metformin Used For?

Metformin is approved by the FDA to treat type 2 diabetes mellitus. ^[1] It is used to:

• Lower blood sugar levels in people with type 2 diabetes
• Improve how the body uses insulin
• Reduce the amount of sugar released by the liver
• Slow the absorption of sugar from the digestive system

It is not used to treat type 1 diabetes, as people with type 1 diabetes do not produce insulin and require insulin therapy instead.

How Does Metformin Work?

Unlike some other diabetes medications, metformin does not increase the amount of insulin the body produces. Instead, it works in three main ways:

• Reduces glucose production in the liver
• Decreases the amount of sugar absorbed from food in the intestines
• Improves insulin sensitivity so the body can use insulin more effectively

Because metformin does not stimulate insulin production, it does not typically cause low blood sugar (hypoglycemia)^[2] when used on its own.

Who Is Metformin Prescribed For?

Metformin is typically prescribed for:

• Adults with type 2 diabetes
• Children aged 10 and older with type 2 diabetes
• People whose blood sugar is not controlled with diet and exercise alone

Important: Metformin is not recommended for people with severe kidney problems (eGFR below 30 mL/min), as this can increase the risk of a rare but serious condition called lactic acidosis. Always tell your doctor about any kidney conditions before starting metformin.

Is Metformin Used for Anything Else?

While the FDA-approved use of metformin is for type 2 diabetes, doctors may sometimes prescribe it for other conditions. These uses are considered off-label, meaning they are not officially approved but are supported by clinical evidence in some cases:

• Polycystic ovary syndrome (PCOS)^[3] — to help manage insulin resistance and hormone levels
• Prediabetes — to help prevent or delay the onset of type 2 diabetes in high-risk individuals
• Weight management — as a supportive treatment in some patients with obesity

Always speak with your doctor before using metformin for any condition other than the one it was prescribed for.

How Long Do You Take Metformin?

For most people with type 2 diabetes, metformin is a long-term medication. It is usually taken indefinitely as part of an ongoing diabetes management plan, alongside healthy eating and regular exercise.

Your doctor may adjust your dose over time or add other medications depending on how well your blood sugar is controlled.

When to Contact a Doctor

Speak with your doctor if you experience:

• Muscle pain, weakness, or difficulty breathing (possible signs of lactic acidosis)
• Severe stomach pain, nausea, or vomiting
• Signs of low blood sugar such as dizziness, sweating, or confusion
• Any new symptoms that concern you after starting metformin

Frequently Asked Questions

Can metformin be used for weight loss?

Metformin is not approved as a weight loss medication, but some people may lose a small amount of weight when taking it, particularly those with insulin resistance. It should not be taken solely for weight loss purposes.

Is metformin safe for long-term use?

Yes. Metformin has been used safely for decades and is generally considered one of the safest long-term diabetes medications available. Regular monitoring of kidney function is recommended during treatment.

Can metformin be used for type 1 diabetes?

No. Metformin is not approved for type 1 diabetes. People with type 1 diabetes require insulin therapy because their bodies do not produce insulin at all.

Can metformin be used for PCOS?

Metformin is sometimes prescribed off-label for polycystic ovary syndrome (PCOS) to help manage insulin resistance, regulate menstrual cycles, and reduce androgen levels. Speak with your doctor about whether it is appropriate for you.

Does metformin cause low blood sugar?

Metformin on its own does not usually cause low blood sugar (hypoglycemia) because it does not stimulate insulin production. However, the risk of low blood sugar may increase if metformin is combined with other diabetes medications such as insulin or sulfonylureas.