Can metformin cause weight loss?

Does metformin cause weight loss? | How does metformin work for weight loss? | Who can take metformin to lose weight? | Metformin alternatives | How to lose weight on metformin | Losing too much weight | Metformin weight gain

Metformin is a commonly used medication to help lower and manage blood sugar in people with Type 2 diabetes. Brand names of metformin include Glucophage, Fortamet, and Glumetza. The diabetes medicine metformin works by helping the body respond better to the insulin it makes naturally, decreasing the amount of glucose the liver makes, and decreasing the amount of glucose the intestines absorb. This prescription medication can help keep blood glucose levels (blood sugar) ( in the target range to prevent or delay long-term, serious health issues, such as heart disease (cardiovascular disease), vision loss, and kidney disease. Additionally, maintaining blood sugar levels can help improve energy and mood. Metformin is available as a tablet, extended-release tablet, and oral solution.

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Does metformin cause weight loss?

Overweight and obesity raise the risk for Type 2 diabetes and losing weight may help prevent developing diabetes, according to the American Diabetes Association. Although metformin is not an FDA-approved weight loss drug, there is research suggesting metformin treatment may lead to a modest amount of weight loss. 

In addition to diabetic patients, a doctor may prescribe metformin for certain people that they think may benefit from it. Metformin may be prescribed off-label for weight reduction in people at high risk for metabolic complications such as those who have prediabetes. Weight management is important when treating and preventing diabetes to reduce the risk of complications and improve overall health. Additionally, metformin may be prescribed off-label for weight gain associated with antipsychotic medications or polycystic ovarian syndrome symptoms such as weight gain.

How much weight do you lose on metformin?

In one study, it was determined that metformin can be an effective drug to reduce weight in an outpatient setting in insulin-sensitive and insulin-resistant overweight and obese patients. Researchers found an average weight loss in the metformin-treated group after six months was 5.8 kg (about 12.8 pounds). The observed weight loss in the metformin-treated patients was 10% or more in 16.2% of people and at least 5% in 47.4% of people.

In another study, it was determined that metformin used in overweight or obese individuals with elevated fasting glucose and impaired glucose tolerance was associated with modest but durable weight loss. Additionally, the study determined that metformin therapy was safe and well-tolerated over many years. Study participants being treated with metformin started at a dose of 850 mg once per day and increased the dose within one month to 850 mg twice daily unless gastrointestinal symptoms warranted a longer titration period. The study found a mean weight change at one year of 2.7 kg (about 6 pounds) in the metformin group. Metformin’s effects reduced the development of diabetes by 31% over an average of 2.8 years of follow-up. Weight loss was a strong predictor of diabetes prevention in both the metformin and placebo groups, with weight loss accounting for 64% of the metformin versus placebo effect on diabetes prevention. Additionally, metformin produced a highly significant reduction in waist circumference.

How does metformin help you lose weight?

While some diabetes drugs may cause weight gain, the use of metformin is not associated with weight gain. Current evidence suggests that the weight change associated with metformin is more likely to be due to decreased intake of calories versus increases in energy expenditure. Metformin appears to impact appetite regulation both directly and indirectly due to its gastrointestinal side effects.

Additionally, the potential for weight loss with metformin could be a result of lowering blood insulin. High levels of insulin (hyperinsulinemia) can lead to sugar cravings, weight gain, and feeling hungry all the time. By regulating the amount of insulin secretion in the body, people may lower their food intake by experiencing fewer carbohydrate cravings and decreased constant feelings of hunger. Additionally, the hormone leptin, which regulates food intake and body mass, may play a role in how metformin can cause weight loss.

Metformin also has a beneficial effect on the blood lipid profile, by lowering plasma triglyceride (fats in the blood) and cholesterol concentrations. High triglycerides or cholesterol in the blood can raise the risk of health conditions like heart disease and stroke.

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Who can take metformin to lose weight?

Metformin may be prescribed off-label for weight loss. Prescribers may be more likely to prescribe metformin for weight loss in people at high risk for metabolic complications such as prediabetes, metabolic syndrome, or polycystic ovary syndrome (PCOS). While not FDA-approved for weight loss, taking metformin for weight loss has been found to be safe and well-tolerated in overweight and obese individuals with elevated fasting glucose levels and impaired glucose tolerance. 

In the study, Long-Term Safety, Tolerability, and Weight Loss Associated With Metformin in the Diabetes Prevention Program Outcomes Study, the studied dose was 850 mg once per day, increasing the metformin dose within one month to 850 mg twice daily unless gastrointestinal symptoms warranted a longer titration period. Prescribers may use a similar off-label metformin weight-loss dosage or one of the below doses for different uses.

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Other diabetic medications that help with weight loss

Along with metformin, several other diabetes medications have been shown to cause weight loss, including GLP-1 receptor agonists, amylin mimetics, and SGLT2 inhibitors. According to the Mayo Clinic, people taking these drugs have seen their blood pressure and cholesterol levels improve. This can often be a desirable and positive effect of these medications for people with Type 2 diabetes.

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How to maximize metformin benefits

• The best time to take metformin is with meals to help lessen the chance of side effects that upset the stomach, including nausea, vomiting, abdominal discomfort, and diarrhea.
• It’s advised not to drink a lot of alcoholic drinks while taking metformin. This includes binge drinking for short periods and drinking a lot of alcohol on a regular basis. Alcohol can increase the chance of getting lactic acidosis for those taking metformin. Lactic acidosis is a buildup of lactic acid in the blood, which is a life-threatening medical emergency that requires treatment in the hospital.
• There are no known drug interactions between grapefruits or grapefruit juice and metformin. Grapefruit juice has shown some major health benefits as it has a higher content of antioxidant compounds in comparison to other commercial fruit juices. Research has shown the benefits of grapefruit juice for diabetics include improving insulin resistance and weight gain, which are risk factors for developing Type 2 diabetes.
• Continue regular exercise, a healthy diet including a low-calorie diet, and other lifestyle changes to both achieve and maintain healthy body weight or BMI (body mass index). For people with diabetes, continue to test blood sugar regularly according to the diabetes care plan established with the healthcare provider.

Losing too much weight on metformin

Taking metformin can lead to modest weight loss that is typically gradual. Metformin is not expected to cause a person to lose too much weight. However, if there is sudden weight loss, significant changes, or an alarming amount of weight loss, people should reach out to their healthcare provider to determine the cause of weight loss.

Can metformin cause weight gain?

Using metformin is not associated with weight gain. While some people may experience weight loss while taking metformin, others may experience little to no weight loss.

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References

• Diabetes-Mange Blood Sugar, CDC
• Metformin Prescribing Information, FDA
• Metformin Dosing, Epocrates