Half of adults stop taking weight-loss drug within a year, study finds
A new study has found that half of adults without diabetes who begin taking the weight-loss drug semaglutide in Denmark stop treatment within a year.
The research, presented at the annual meeting of the European Association for the Study of Diabetes (EASD) in Vienna, raises concerns about the long-term use of these costly medicines, which are designed to be taken continuously to maintain their benefits.
Semaglutide belongs to a class of drugs known as glucagon-like peptide-1 receptor agonists (GLP-1RAs). Originally developed for diabetes, they have become widely prescribed for weight loss after being shown to reduce appetite and increase feelings of fullness. However, the drugs are expensive, costing around €2,000 per year for the lowest dose in Denmark and users often regain weight once they stop treatment.
The study analysed data from nationwide health registries, covering 77,310 adults who began semaglutide for weight loss between December 2022 and October 2023. More than half (40,262 people, median age 50 years, 72 per cent women) had stopped taking the drug after 12 months.
Discontinuation was common early on: 18 per cent stopped within three months, 31 per cent within six months and 42 per cent within nine months.
Professor Reimar W. Thomsen of Aarhus University and Aarhus University Hospital, who led the study, said: “These medications are not meant to be a temporary quick fix. To work effectively, they need to be taken long term. All of the beneficial effects on appetite control are lost if the medication is stopped.”
The analysis highlighted several factors linked to stopping treatment. Younger adults aged 18–29 were 48 per cent more likely to discontinue than those aged 45–59. People living in low-income areas were 14 per cent more likely to stop than those in wealthier neighbourhoods, suggesting cost is a key barrier.
Side-effects also played a role. Those with a history of gastrointestinal conditions were nine per cent more likely to discontinue, while people with a history of psychiatric medication were 12 per cent more likely to stop. People with cardiovascular disease or other chronic illnesses also had a slightly higher risk of early discontinuation.
Men were 12 per cent more likely than women to end treatment within a year, which researchers suggested may reflect lower weight loss outcomes compared with women.
Professor Thomsen said the findings shed light on real-world patterns of use: “With over half of adults in Europe living with overweight or obesity, understanding who may benefit most from interventions that encourage adherence is essential to improving treatment use and subsequent health outcomes.”
The researchers noted limitations, including a lack of information on participants’ body mass index or the amount of weight lost during treatment, as well as limited data on mild side-effects or financial factors that may have influenced discontinuation.