Does Metformin Causes Weight Loss?

Metformin is the first line of treatment used to control blood sugar in diabetes patients.

It is also used to treat polycystic ovary syndrome, cancer risks linked to diabetes and non-alcoholic fatty liver disease.

The chemical name of metformin is dimethyl biguanide.

Its origin can be traced back to the use of the plant, Galega officinalis (French lilac).

This plant is rich in guanidine and in the late 1800s it was shown to have blood glucose lowering effect in animals.

In later centuries synthetic guanidine derivatives were developed, one of them being metformin.

Metformin is used to promote weight loss in overweight or obese individuals.

It is proposed that metformin works by ameliorating insulin resistance and suppressing glucose formation by the liver. It also helps in reducing cholesterol and blood lipid levels.

Metformin is one of the two oral anti-diabetic agents approved by WHO.

The aim of this article is to investigate the effect of this drug on body weight and not to suggest its use as an anti-obesity drug.

Can Metformin cause Weight Loss?

A review study based on metformin and its effect on body weight report that unlike other oral anti-diabetic agents, metformin does not cause weight gain and instead it prevents weight gain linked with insulin treatment.

The Diabetes Prevention Program conducted in USA reported that metformin is safe and well-tolerated drug for diabetes prevention.

Results of this study showed that individuals receiving metformin experienced significant weight loss and the decrease in waist circumference.

Also, weight loss outcomes increased in the group who continued taking the treatment.

Interestingly, metformin has been evaluated for its effect on weight loss in individuals who don’t suffer from diabetes.

This study showed that a dose up to 2500mg caused significant weight loss.

Metformin has also been used in treating obesity in children and adolescents.

It has been proven that this drug can cause modest decrease in weight and BMI and favorably impact glucose and insulin levels in obese children.

Metformin along with lifestyle modification is proven to be efficient and safe in treating the obese adolescents with metabolic syndrome.

However, a review of 9 clinical trials involving effect of metformin on the weight of healthy individuals concluded that adequate data is not available to confirm whether metformin helps in weight loss in obese but otherwise healthy individuals.

But lack of evidence or foolproof design of studies alone can’t suggest that metformin does not cause weight loss.

Many clinical trials have shown that metformin indeed helps with weight reduction.

Let’s find out how.

How does Metformin Cause Weight Loss?

The potential mechanism thought to be involved in weight loss by metformin is control of appetite and modulation of fat oxidation and storage in body tissue

An elaborate explanation as to how this actually occurs is not readily available.

Following sections demonstrate the different molecular targets manipulated by metformin to support weight loss.

Metformin Help in Weight Loss

1. It acts as an appetite suppressant

A dose of 1700mg of metformin is proven to have marked appetite suppressing properties.

In this study individuals treated with metformin experienced a weight loss of around 8 kg more than the untreated group.

2. It controls blood sugar and improves insulin levels

The fact that it is an anti-diabetic agent, it is obvious that the drug controls elevation in post meal glucose levels.

Balanced glucose metabolism helps prevent weight gain.

3. It regulates leptin levels

Leptin is a hormone that promotes satiety and controls appetite.

Metformin reduces serum leptin concentrations which are linked with increased glucose tolerance and reduced food intake.

4. It increases adiponectin level

Adiponectin is a hormone that favors glucose metabolism and supports the breakdown of fats.

Metformin increases adiponectin levels which lead to a reduction in BMI.

5. It increases the activity of glucagon like peptide (GLP-1)

GLP is a hormone secreted by intestinal cells which stimulates insulin secretion. GLP-1 regulates appetite and food intake and decreased secretion of GLP-1 can lead to obesity.

Metformin prevents degradation and promotes the activity of GLP-1 in obese non diabetic patients.

6. It influences AMPK and SIRT1 pathway

Metformin regulates this biochemical pathway which suppresses fat deposition.

Activation of protein AMPK by metformin leads to oxidation of fats, decrease in enzymes that support the production of lipids and also increases in use of glucose as energy.


One of the risks associated with metformin therapy is the development of lactic acidosis (build up of lactic acid in the blood).

Metformin suppresses TSH levels ; individuals suffering from thyroid problems should avoid metformin.

Individuals suffering from metabolic ketoacidosis should not take metformin. In case of pregnancy and lactation avoid this drug.

Metformin is reported to cause low blood sugar and can even have drug interactions.

Consume metformin only when advised by a physician.


Metformin is a drug that is used primarily to treat diabetes.

Research indicates that it promotes weight loss in healthy patients and also in those suffering from diabetes, PCOS.

Outcomes improve if take over a long period of time.

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