Weight-loss injections deliver fast results—but rapid regain follows after stopping

New research shows that weight-loss injections help people shed significant weight but may lead to rapid regain once treatment stops. Scientists reviewed 37 studies involving over 9,000 patients to compare these drugs with traditional diets. The findings highlight concerns about long-term effectiveness after discontinuation.

The analysis found that overweight individuals using GLP-1 injections, such as Wegovy and Mounjaro, lose about one-fifth of their body weight. However, after stopping the medication, they regain an average of 0.8 kg per month. This rate is four times faster than the 0.1 kg monthly regain seen in those who end a diet or exercise plan.

Only eight studies examined newer GLP-1 drugs, with the longest follow-up lasting just one year after patients discontinued treatment. Novo Nordisk produces some of these newer options, including the oral Semaglutide-based Wegovy tablet, which received FDA approval in the USA on December 22, 2025. Researcher Susan Jebb warned that rapid weight regain poses a risk for patients who stop using these injections. The findings come from clinical trials, but further studies are needed to assess the long-term impacts of these drugs.

The research confirms that weight-loss injections deliver faster results than dieting but carry a higher risk of quick rebound after stopping. With limited long-term data available, experts stress the need for more studies on sustained effects. Patients considering these treatments may need to weigh short-term benefits against potential challenges after discontinuation.