Study highlights limits of short-term medication use
People who stop using weight loss injections regain the weight they lost in under two years, and at a much faster pace than those following other weight loss approaches, according to a major new analysis. The findings add to growing evidence that obesity treatments relying solely on medication may struggle to deliver lasting results without long-term support.
The study reviewed 37 previous trials involving more than 9,300 participants who used weight loss drugs known as GLP-1 agonists. These medications, initially developed to treat diabetes, work by mimicking a hormone that helps regulate appetite and increase feelings of fullness.
Rapid regain after treatment ends
On average, participants were treated for about nine months and then followed for roughly eight months after stopping medication. The analysis found that weight was regained at an average rate of 0.4 kilograms per month once treatment ended. Most participants returned to their original weight within approximately 1.7 years.
During treatment, people lost an average of 8.3 kilograms. However, nearly 5 kilograms of that weight returned within the first year after stopping the drugs. The pace of regain was almost four times faster than what has been observed in behavioural weight loss programmes focused on diet and physical activity.
Obesity viewed as a chronic condition
Researchers emphasized that the rapid regain should not be seen as a failure of the medications themselves. Instead, it reflects the chronic and relapsing nature of obesity, which often requires ongoing management rather than short-term intervention.
The study also found that improvements in cardio-metabolic markers such as blood pressure and cholesterol faded after treatment stopped, returning to baseline levels within about 1.4 years.
Implications for long-term care
Experts say the findings underline the importance of pairing weight loss drugs with sustained lifestyle, behavioural, and environmental support. While these medications can deliver meaningful short-term results, they are unlikely to be effective as standalone solutions.
Health advocates note that long-term success depends not only on individual behaviour but also on broader factors such as food marketing, affordability of healthy options, and access to structured weight management services.
Looking ahead
Weight loss injections are increasingly used within healthcare systems, but the study suggests their benefits may be temporary without comprehensive follow-up care. As use expands, policymakers and clinicians face growing pressure to design treatment models that support lasting weight management rather than short-term loss alone.