Half of weight loss drug treatments are discontinued after one year

BarcelonaSemaglutide drugs—which mimic a hormone that regulates blood glucose levels and are used for diabetes and obesity—became a target of the pharmaceutical industry and have ultimately ended up being prescribed in clinics and dispensed by pharmacies as one of the most effective tools. However, the ease with which they are discontinued prematurely is beginning to worry endocrinologists. A study conducted in Denmark (where the pharmaceutical giant Novo Nordisk manufactures) warns that half of semaglutide users discontinue treatment within a year.

"The level of decline is worrying because these are not drugs designed to be a quick, temporary fix," explains the study's author, Professor Reimar W. Thomsen, of the Department of Clinical Epidemiology at Aarhus University and the hospital in the same town. "For them to work effectively, they must be taken long-term. All the beneficial effects on appetite control are lost if the medication is stopped," warns the expert, who will present the report at the annual meeting of the European Association for the Study of Diabetes, which runs until September 19 in Vienna.

Originally developed for diabetes, drugs that mimic the functioning of the hormone GLP-1 stimulate insulin production, slow gastric emptying, and increase the feeling of satiety. But, above all, they essentially cause fat loss, not just overall weight. However, they are expensive medications (the price is around 200 euros per month) that require chronic use for the effects to last. If the medication is stopped, the rebound effect—as the regaining of lost weight is called—is common.

Researchers led by Thomsen analyzed data from Danish health registries to see how likely adults without diabetes were to stop taking semaglutide for weight loss and for what reasons since the drug Wegovy began being prescribed in Denmark. Wegovy is the second generation of the diabetes drug Ozempic. Specifically, between December 2022 and October 2023, of the 77,310 identified semaglutide weight loss users, more than half (40,262) were no longer taking Wegovy after one year. 18% discontinued treatment three months later, 31% after half a year, and 42% after another three months.

Seventy-two percent of users of this medication were women, but men were 12 percent more likely to discontinue treatment. The analysis found that the most common factor influencing the likelihood of discontinuing the medication was age, with younger users—between 18 and 29 years old—up to 48 percent more likely to stop Wegovy during the first year than middle-aged adults (between 45 and 59 years old). Similarly, those living in low-income areas were 14 percent more likely to discontinue treatment during the first year than those living in high-income areas. Both factors highlight the high price of these medications (€2,000 per year for the lowest dose), "which is a major barrier to treatment for many people," Thomsen warns.

People with a history of psychiatric medication were also 12 percent more likely to drop out, while those with cardiovascular or chronic conditions were around 10 percent more likely. Considering that "more than half of adults in Europe are living with overweight or obesity," understanding who can benefit most from interventions that prevent drug discontinuation "is essential to improving treatment uptake and subsequent health outcomes and quality of life," Thomsen concludes.

No public funding

Leading medical societies, such as the Endocrine Society, have long warned that drugs like semaglutide should be considered chronic treatments for patients with long-standing obesity or associated conditions such as diabetes or hypertension. In fact, experts warn that discontinuing treatment after one year only makes sense when serious side effects appear, when weight loss is insufficient—less than 5% in the first 3 to 6 months at maximum doses—or when the doctor deems continued medication unjustified.

According to data from the 2023 Catalan Health Survey (ESCA), approximately half of the adult population between 18 and 74 years of age is overweight: 34.7% are overweight and 15.3% are obese. The drug Wegovy began selling in Spain in May 2024 with a prescription, but the public health system currently does not fund it, forcing patients to bear the entire cost of treatment.