Metformin Weight Loss: Truth Behind its Side Effect

Recently people are much talking about the drug Metformin and its "miracle" weight-loss qualities.

This article will demystify the aura surrounding Metformin (𝐶4 𝐻11 𝑁5 ), clear up its real purpose, and alert you to possible adverse effects.

What is Metformin?

Metformin is a drug prescribed to address type-2 diabetes. It is also prescribed for obese or overweight individuals at risk of developing diabetes, i.e., prediabetic.

How it Works?

Metformin works to address diabetes by improving the efficiency and effectiveness with which the body's muscles use glucose and by minimizing glucose release by the liver. It also promotes better functioning of insulin, thereby raising insulin sensitivity. So, it can also be prescribed for overweight individuals who display insulin resistance.

With better insulin function, your blood sugar levels drop concomitantly. Metformin drugs like Glucophage are usually used in conjunction with other medications. Doctors suggest lifestyle changes to maximize the benefits of this drug regime.

Currently, FDA, or the U.S. Food and Drug Administration, has only cleared the use of Metformin to treat type 2 diabetes and considered it the first-line treatment.

Does Metformin Cause Weight Loss and How?

Metformin has been shown to promote moderate weight loss among the people it is prescribed for. It is very different compared to other diabetes drugs, which usually make people put on weight. But it's important to note that weight loss is a secondary side-effect. The medication isn't prescribed for weight loss, but dropping a few pounds is a happy coincidence.

Initially, taking Metformin makes most patients quite sick to their stomachs. They suffer nausea, diarrhea, vomiting, and an upset stomach. These side effects could cause a temporary but almost immediate loss in water weight. The side effects can also last quite a while, causing a decrease in appetite and a reluctance to eat, which may also cause weight reduction.

But Metformin has an array of other stimulatory mechanisms responsible for weight loss. For one, the body either produces more leptin or becomes more sensitive to leptin – the exact modality remains unclear. The leptin hormone is responsible for increased feelings of fullness, which curb appetite. The GLP-1 hormone is also thought to be released with this drug, which further blocks the GLP receptor and suppresses appetite. The simultaneous function of these hormones could promote weight loss by limiting and regulating the body's need to eat.

Metformin also supposedly reduces visceral fat stored around organs in the abdominal cavity. Because it burns this fat, patients may see a reduction in their waistline and belly fat. It may also affect the gut bacteria or microbiome ecosystem, the enhanced activity of which also interplays with other hormones and brain activity to reduce hunger and food intake.

Is the Weight Loss from Metformin Permanent?

The FDA has not approved this drug as a stand-alone medicine for weight loss. But doctors use it as off-label medication for many other purposes. For example, it is used for people who are overweight/obese and run the risk of developing diabetes or showing signs of insulin resistance. Technically, Metformin isn't approved for even these adjacent purposes. But here may be a therapy deficit in such areas that makes using these drugs crucial for conditions where other methods have failed to work. Since a drug cannot be tested for all purposes and indications, off-label use isn't illegal in the strict sense. But its use should be self-regulated by doctors and used only where necessary, effective, and safe. Uncontrolled or unregulated use can cause adverse health effects and endanger patients' lives.

Weight loss may be a reason for prescribing the drug. In case you are prediabetic or have metabolic complications due to obesity. But weight loss is temporary and dependent on several factors. If you take Metformin, continue eating indiscriminately, and remain sedentary, you may not even lose weight. But with all other factors remaining the same, you will probably gain the weight back once you regain your normal appetite – it doesn't substitute an active lifestyle. In any case, you can only lose about 3-5 kg in about four or five years. The proper diet and fitness regime can sustain and increase gradually over the years.

Metformin isn't a magic drug that promotes sudden or drastic weight loss. It isn't a quick fix for an unhealthy routine. If you have to lose a lot of weight, for example, 10-15 kgs, then Metformin's contribution is minimal.

Is using Metformin for weight loss Safe?

So far, it hasn't proven problematic for Type 2 diabetes and parallel concerns. However, since it isn't prescribed for type 1 diabetes, obesity, or weight management, you need to be responsible for its use. A doctor should prescribe it and must use only the stated amounts. Dosages should be adjusted based on any side effects, significantly if you don't suffer from the primary issue targeted i.e., Type 2 diabetes. Metformin use for weight loss is unlikely to develop serious side effects but should be strictly monitored. Depending on their body types and metabolic activity, it may only be effective for some.

Adults are not to have more than 25 ml a day – the ideal dosage is between 5-8.5 ml daily. For children, the recommended dosage is only 5ml. The range for tablets is between 500 and 1000 mg and should never exceed 2500 mg. Only liquid and standard tablets are currently available on the market.

Some extended-release Metformin tablets were recalled recently due to the suspected presence of a potential carcinogen. Until the risk of cancer-causing ingredients is ruled out, they will remain unavailable.


Metformin can be used if the situation so necessitates it. But taking a drug as a shortcut is never a good idea. As we've seen with the recall, medicines can have unintended consequences. It's always best to lose weight naturally and healthily.