Metformin and weight loss have a long-standing link. First of all, it was noted that users who took the drug to control their blood glucose also lost 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 hypotheses.
One of the theories suggests that this drug has the ability to reduce appetite. Therefore, the calorie balance is in favor of weight loss. Anyway, it should be clear that it is not a strategy of choice to lose weight. For what reason? Here we explain it in detail.
What is metformin?
Metformin is an oral antidiabetic drug, that is, it is indicated as the first choice in people with type 2 diabetes . This form of the 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 in the end results in less availability of the nutrient.
In addition, metformin also works in the liver, where it helps stop glucose production. It forces you to make glycogen, which is a storage form of sugar. Finally, another important point of action is in the muscle, where the sensitivity of this tissue to insulin improves .
Ultimately, the drug does not lower a person’s blood glucose, but rather prevents it from rising after meals. For this reason, their administration schedules are in relation to the big meals of the day. 500 to 800 milligrams are usually prescribed with lunch and dinner.
The most severe cases reach up to 1000 milligrams, twice a day, although 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.
Keep reading: Treatment of diabetes mellitus
The side effects of metformin
Metformin can cause weight loss as a side effect. This does not always mean an adverse reaction , but, in this as in other drugs, there are issues that occur in parallel to what is intended when indicated by the doctor.
First of all, we will talk about 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, diarrhea and abdominal pain . Increased peristalsis leading to flatulence and a feeling of bloating is also common .
Given this combination of signs and symptoms, the patient may reduce their intake due to discomfort. Metformin may not be discontinued, as the medical indication is usually precise and strong. Diabetes leaves no room for interpretation on how to deal with it. The priority is to lower blood glucose.
On the other hand, there is a serious adverse effect of the drug that, although rare, is life-threatening. It is lactic acidosis . In this situation, the blood fills with lactic acid, the product of a deviation in 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
One of the strongest hypotheses is about the alteration of appetite. It is suspected that it reduces the hunger of those who consume it, which favors the energy balance. If to this we add the carbohydrate restriction diet that is usually indicated, the combination is favorable.
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 meaning in English). It is not a magic pill nor was it created with the aim of supporting a low calorie diet. It should be clear that this situation was seen as collateral .
Find out more: How diabetes affects the digestive system
Can Metformin Be Prescribed For Weight Loss?
How to be prescribed, it 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 happens many times 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, the insulin response would improve.
The same criteria apply to metabolic syndrome or polycystic ovary syndrome , in which the lack of action of insulin is combined with a high weight. Again, metformin appears as the 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 names 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 most likely receive a prescription for metformin. It is the drug of choice to initiate glycemic regulation . It may be prescribed in combination with another, and in aid of dietary and lifestyle changes.
The scientific evidence is sufficient to rely on this substance to changes in glucose levels. In fact, all over the world it is part of the formula used by endocrinologists.
Still, if we only want to use it for weight loss, we should be careful. Given the lack of evidence, it is not known whether it can cause adverse effects in healthy adults in the long term. It is best to avoid its consumption in these cases and look for other strategies to achieve a healthy weight.