New research indicates individuals who discontinue weight-loss injections like Mounjaro or Wegovy may regain lost weight at a rate four times faster than those who stop traditional dieting and exercise regimens. Published data in the British Medical Journal suggests that patients using these injections can lose approximately one-fifth of their body weight, but typically regain 0.8 kg each month after stopping treatment, potentially returning to their original weight within a year and a half.
Rapid Weight Regain a Key Concern
Dr. Susan Jebb, an investigator from Oxford University, cautioned that individuals considering these injections “need to be aware of the risk of fast weight regain when the treatment ends.” Dr. Jebb also noted that the findings are based on data from medical trials and further research is needed to fully understand the long-term effects of these medications.
The study compared the effects of these injections to conventional weight loss methods across 37 studies with over 9,000 participants. While those using the newer GLP-1 drugs, such as Wegovy and Mounjaro, experienced more significant weight loss, the data suggests a faster rate of regain upon cessation. Individuals who dieted experienced a slower rate of weight creep—around 0.1 kg per month—though this varied.
The NHS currently recommends these injections for individuals with obesity-related health risks, not simply for cosmetic weight loss. Doctors are also advised to prescribe accompanying lifestyle changes, including healthy eating and regular exercise, to support long-term weight management. Some medical professionals suggest treatment should be considered ongoing, given the potential for relapse.
Experiences shared by individuals who have discontinued the injections describe a sudden return of intense hunger. One woman reported, “It was like something opened up in my mind and said: ‘Eat everything, go on, you deserve it because you haven’t eaten anything for so long.'”
Dr. Adam Collins, a nutrition expert at the University of Surrey, explained that the mechanism of these drugs—mimicking the hormone GLP-1 which regulates hunger—may contribute to the amplified weight regain. “Artificially providing GLP-1 levels several times higher than normal over a long period may cause you to produce less of your own natural GLP-1, and may also make you less sensitive to its effects,” he stated. “That’s not a problem when taking the drugs, but as soon as you withdraw this GLP-1 ‘fix’, appetite is no longer kept in check and overeating is far more likely.”
Growing Use and Future Considerations
According to recent estimates, approximately 1.6 million UK adults have used these injections in the past year, primarily through private prescriptions. An additional 3.3 million express interest in using them in the coming year, representing roughly one in ten adults. Use is more common among women and those in their 40s and 50s.
Professor Naveed Sattar from Glasgow University suggested that even short-term use of these injections could offer health benefits by quickly reducing weight. However, he emphasized the need for larger and longer-term trials to assess the full impact. Continued use over three to four years, he noted, may be necessary to maintain significant weight loss.
Frequently Asked Questions
What happens when someone stops taking Wegovy or Mounjaro?
The research suggests that individuals typically regain 0.8 kg every month after stopping these injections, potentially returning to their pre-treatment weight within a year and a half.
Who is eligible for these injections on the NHS?
The NHS recommends these injections for people who are overweight with obesity-related health risks, not for those seeking weight loss for cosmetic reasons.
Are these injections a long-term solution for obesity?
The findings suggest that ongoing treatment may be necessary to maintain weight loss, similar to managing chronic conditions like diabetes or hypertension.
Given the potential for rapid weight regain, how might individuals best prepare to discontinue these medications?