Many people around the world are turning to new prescription drugs to help them lose weight.
These medicines can work very well while you are taking them, but a new study suggests that the weight loss may not last after you stop.
In fact, many patients tend to put some of the weight back on once they finish their course of medication.
The research, published in the journal BMC Medicine, looked at information from 11 clinical trials involving patients who had been prescribed weight loss drugs.
This type of research, called a meta-analysis, combines the results from many different studies to find overall patterns. In this case, scientists wanted to know what happens to people’s weight once they stop taking these medicines.
There are currently six weight loss medicines approved by the United States Food and Drug Administration (FDA). These include orlistat, phentermine-topiramate, and semaglutide. Another group of medicines, known as GLP-1 drugs, was originally designed for people with diabetes but is now often used for weight loss too.
One example is tirzepatide. While these medicines have helped many people lose weight, doctors have noticed that the weight can start creeping back once the drugs are stopped.
The researchers, led by Xiaoling Cai and Linong Ji, looked at studies from different countries. Altogether, they analysed data from 1,574 people who took weight loss medicines and 893 people in control groups who did not.
The studies tracked changes in body weight and body mass index (BMI) after patients stopped their treatment.
The 11 studies included in the review focused on a variety of medicines: six involved GLP-1 receptor agonists, one looked at a GLP-1 and GLP dual drug, one examined orlistat, two studied phentermine-topiramate, and one looked at naltexone-bupropion.
The researchers also took into account other factors that could affect the results, such as whether patients had diabetes and whether they made lifestyle changes like diet and exercise.
The findings were clear: people lost a noticeable amount of weight while taking the drugs, but they began to regain weight about eight weeks after stopping them. This weight regain tended to continue for around 20 weeks before levelling off.
The amount of weight gained back varied depending on the type of drug and the person’s lifestyle habits. For instance, in one study, people who took tirzepatide for 36 weeks regained almost half the weight they had lost once they were switched to a placebo.
The authors pointed out that their research did not include studies on lifestyle changes alone or on weight loss surgery, so they could not compare how these methods stack up against each other over the long term. Still, weight regain is not unique to medication—it also happens after many other weight loss methods, including gastric bypass surgery.
Overall, the study highlights that while weight loss drugs can be effective, keeping the weight off after stopping them can be a challenge.
This suggests that people may need ongoing support, lifestyle changes, or even continued treatment to maintain their results. It also shows that obesity is a long-term condition that may require ongoing management, much like high blood pressure or diabetes.
If you care about obesity, please read studies about Scientists find new key cause of obesity and findings of Double whammy: diabetes drug also knocks out obesity.
For more information about weight loss, please read studies about Scientists find secrets to long-term weight loss success and findings of Weight loss surgery linked to this mental disease.
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