Does metformin cause weight loss?

Official answer

by Drugs.com

Metformin, an oral type 2 diabetes medicine, may lead to a modest weight loss and does not usually lead to significant, if any, weight gain. In various clinical studies, when metformin was used alone, it led to a weight loss of 0.7 to 3.8 kg (1.5 to 8.4 lbs) in patients. Many clinicians consider metformin a "weight neutral" treatment, meaning it does not cause a significant amount of weight gain or loss.

Metformin (brand name: Fortamet, Glumetza) is approved by the FDA to be used with diet and exercise to improve glycemic (blood sugar) control in adults and pediatric patients 10 years of age and older with type 2 diabetes mellitus. It is classified as a biguanide and has been approved by the FDA since 1995.

Most studies have not seen a significant amount of weight loss with metformin when used alone, and it does not meet the weight loss levels seen in studies for Ozempic, Wegovy or Mounjaro. It also does not cause weight gain like insulin or a sulfonylurea treatment (for example: glimepiride, glipizide, glyburide).

Metformin is usually the first drug used to treat patients with type 2 diabetes. Metformin is favored over many other diabetes drugs as initial treatment because of its ability to control blood sugar levels, lack of weight gain and low blood sugar, oral formulation, and generic affordability.

Overall, the best way to lose weight while taking metformin is to adhere to a recommended diet and exercise program. It can also be used in combination with other type 2 diabetes medications, including:

Staying at a healthy weight is an important part of controlling type 2 diabetes. If you are concerned about gaining weight with your medicine, speak to your healthcare provider about drug and non-drug treatments that may help promote weight loss as well as control your blood sugar. Today, many treatments are available that not only effectively control blood sugar but can also help with significant weight loss in type 2 diabetes.

Is metformin approved for weight loss?

Metformin is not specifically approved to be used for weight loss as a stand-alone therapy, but may lead to a moderate weight loss in some people. Metformin, when used with diet and exercise, is approved by the FDA for blood sugar control in the treatment of type 2 diabetes in adults and children 10 years of age and older.

Some studies have shown that metformin can lead to weight loss when evaluated in non-diabetic individuals with obesity.

The authors concluded that metformin was an effective drug to reduce weight in a naturalistic outpatient setting in insulin sensitive and insulin resistant overweight and obese patients.

Which diabetes treatments work best for weight loss?

Examples of type 2 diabetes medicines that are associated with weight loss include:

Note: Liraglutide (Saxenda) and semaglutide (Wegovy) are approved for weight loss in people with or without type 2 diabetes. Tirzepatide (Mounjaro) has also been shown in clinical trials to be useful for weight loss; however, it is not currently approved as a weight loss drug. The manufacturer submitted approval for this use to the FDA in 2022, with a decision expected in 2023.

Type 2 diabetes medicines that tend to be weight neutral, not increasing or decreasing weight substantially, include:

This is not all the information you need to know about metformin for safe and effective use and does not take the place of your health care provider’s directions. Review the full product information and discuss this information and any questions you have with your doctor or other health care provider.