Metformin and weight loss have a long-standing link. First, it was noted that users who consumed the drug to control their blood glucose also reduced kilograms of weight. At first, it was not known if this decrease in fat was due to diet or medication; however, it was a starting point for the hypotheses.
One of the theories suggests that this medicine can reduce appetite. Therefore, the calorie balance is in favour of weight loss. Anyway, it should be clear that it is not a choice strategy to lose weight. For what reason? Here we explain it in detail.
What is metformin?
Metformin is an oral antidiabetic medication; that is, it is indicated of the first choice in people with type 2 diabetes. This form of pathology is one in which the use of injectable insulin is not yet required.
Its form of action focuses on preventing the amount of circulating glucose in the blood from rising. This is achieved by blocking the absorption of sugars in the intestine, which translates, in the end, into less availability of the nutrient.
Also, metformin works in the liver, where it helps stop glucose production. It forces you to make glycogen, which is a form of sugar deposition. Finally, another important action point is in the muscle, where it improves the sensitivity of this tissue to insulin.
Ultimately, the drug does not lower a person’s blood glucose but prevents it from rising after meals. Therefore, their administration hours are with the great meals of the day. 500 or 800 milligrams are usually prescribed with lunch and dinner.
The most severe cases reach up to 1000 milligrams, twice a day. However, at that point, it is preferred to combine it with another oral hypoglycemic agent, such as glimepiride, glibenclamide, among others. The choice is very particular for each clinical picture.
The side impacts of metformin
Metformin can induce weight loss as a side impact. This does not always mean an adverse reaction, but, in this as in other drugs, some issues occur in parallel to what is intended when indicated by the doctor.
In the first place, we will talk about the adverse effects, which are those that happen in a negative sense. They are not always present, but when they are, they could explain weight loss in some patients, since most are gastrointestinal.
Regular users of the drug suffer from nausea, diarrhoea and abdominal pain. An increase in peristalsis is also common, leading to flatulence and a feeling of bloating.
Given this combination of signs and symptoms, the patient may reduce their intake due to discomfort. You may not stop metformin, as the medical indication is usually accurate and forceful. Diabetes leaves no room for interpretations of how to deal with it. The priority is to lower blood glucose.
On the other hand, there is a serious adverse effect of the medicine that, although it is not frequent, represents a vital risk. This is lactic acidosis. In this situation, the blood fills with lactic acid, the product of a deviation of the cellular metabolism due to the drug. Thus, the person may suffer symptoms such as the following:
- Extreme weakness
- Heart and lung rhythm disturbances.
The side effect of weight loss
The association between weight loss and metformin is not fully understood. Various investigations have been carried out to find out the reason for the effect, but none has been conclusive.
One of the strongest hypotheses is about impaired appetite. It is suspected that it reduces the hunger of those who consume it, which favours the energy balance. If we add to this the carbohydrate restriction diet that is usually indicated, the combination is favourable.
In any case, the effect on body weight is not immediate. The studies available have found that the benefit appears after a year of continuous use, and are consistent between 6-15 years later.
Therefore, the effect is considered long-term weight loss (LTWL or long-term weight loss, for its English meaning). It is not a magic pill, nor was it created to support a low-calorie diet. It should be clear that this situation was seen as collateral.
Can metformin be prescribed to lose weight?
How to be prescribed is possible. In any case, it is a drug for type 2 diabetes, designed and marketed to lower blood glucose levels in patients with metabolic disorders.
What often happens is that diabetic patients with insulin resistance are obese or overweight. In these particular cases, metformin appears as a first-line option, since it would reduce not only circulating sugar, but also body fat. With all this, it would improve the insulin response.
The same criteria apply for metabolic syndrome or polycystic ovarian syndrome, in which the lack of action of insulin is combined with high weight. Again, metformin appears as a logical therapeutic strategy.
However, if a professional prescribes it for the sole purpose of helping you lose weight, without diabetes, you are using it “off-label.” This expression refers to the prescription for a utility that is not endorsed. It can be done, but there is no scientific evidence to back it up.
Metformin for diabetic patients
A type 2 diabetic person will surely receive a prescription for metformin. It is the drug of choice to initiate glycemic regulation. It may be prescribed in combination with another, and to help with dietary and lifestyle changes.
The scientific evidence is sufficient to trust this substance in the face of changes in glucose levels. Worldwide it is part of the formula that endocrinologists use.
Still, if we only want to use it for weight loss, we should be careful. Given the lack of evidence, it is unknown whether long-term it can cause adverse effects in healthy adults. It is best to avoid consumption in these cases and seek other strategies to achieve a healthy weight.