...
By Jordan King
Reporter
0
Share
Newsweek is a Trust Project member
See more of our trusted coverage when you search.Prefer Newsweek on Googleto see more of our trusted coverage when you search.
People who stop taking weight-loss injections such as Wegovy and Mounjaro regain pounds much faster than those who halt exercising and dieting, a new medical study shows.
Research published in The British Medical Journal this month suggests that people lose around a fifth of their body weight when taking the jabs. But once they quit them, they regain 0.8 kg per month on average, meaning they return to their pre-treatment weight in around a year-and-a-half, according to the findings.
The study was based on the analysis of more than 9,000 adults worldwide taking weight management medications (WMMs).
Read More on News
Novo Nordisk, the parent company of Wegovy, told Newsweek that this study "highlights the chronic nature of obesity and suggest that ongoing treatment is necessary."
Eli Lilly and Company, the parent company of Mounjaro, told Newsweek: "When treatment is stopped, weight can return, which reflects the biology of the condition rather than a lack of effort."
Newsweek reached out to the Centers for Disease Control and Prevention (CDC) via email for comment.
...
Why It Matters
The findings come as usage of weight-loss jabs surges in the United States — a Rand Corporation survey from last August found that nearly 12 percent of Americans had used glucagon-like peptide (GLP-1) drugs, including Wegovy and Mounjaro, for weight loss.
The findings also suggest that users need to take the drugs long-term for continued effect, which could have a large financial impact on them.
What To Know
The study, published in The BMJ on January 7, summarized evidence from 37 trials involving 9,341 participants, most of whom received newer "incretin mimetic" drugs such as semaglutide (Wegovy) or tirzepatide (Mounjaro).
The key findings included:
- After stopping WMMs, adults regained an average of 0.4 kg (0.9 lb) per month; for newer drugs, they regained an average of 0.8 kg (1.8 lb) per month.
- Nearly all lost weight was regained within 1.5 years of stopping new drugs such as Wegovy and Mounjaro.
- Cardiometabolic health improvements—such as better blood sugar, cholesterol, and blood pressure—also returned to a baseline within a similar timeline.
- In contrast, individuals who shed weight through behavioral management programs regained weight at a rate of just 0.1 kg (0.2 lb) per month, requiring nearly four years to return to a baseline weight.
- Behavioral support during or after WMM therapy did not significantly slow weight regain after stopping the drugs.
The review notes that almost half of patients discontinued the jabs within the first year, meaning long-term benefits remained uncertain.
The study's authors said: "These findings suggest caution in short term use of these drugs without a more comprehensive approach to weight management."
What People Are Saying
Dr. Susan Jebb, lead investigator of the study and a University of Oxford professor, told the BBC: "People buying these need to be aware of the risk of fast weight regain when the treatment ends. The findings come from medical trials rather than real life and more studies of the longer-term effects of new slimming jabs would be helpful."
A Novo Nordisk spokesperson told Newsweek: "Wegovy (semaglutide injection) is indeed indicated for weight management, and it’s expected that some level of weight regain can occur upon discontinuation of the medicine. Our own study published in 2022 from the STEP1 trial demonstrated that treatment withdrawal of Semaglutide resulted in the regain of two-thirds of the weight loss within 52 weeks. These findings highlight the chronic nature of obesity and suggest that ongoing treatment is necessary to maintain improvements in weight and overall health for patients, similar to the management of other chronic conditions such as diabetes or hypertension."
An Eli Lilly and Company spokesperson told Newsweek: "Obesity is a chronic progressive disease, and people living with obesity deserve care that reflects that reality. Many long-term conditions, such as high blood pressure or diabetes, need ongoing treatment. Authorised weight-management medicines, when prescribed appropriately, can be part of longer-term care alongside healthy eating, physical activity, and medical follow-up. When treatment is stopped, weight can return, which reflects the biology of the condition rather than a lack of effort. Lilly continues to study the long-term effects of these medicines and works closely with healthcare professionals and people living with obesity to support their safe and appropriate use."
What Happens Next
The study's authors recommend that guidelines be reviewed so that patients receiving the medications are made aware of the likelihood of rapid weight regain unless the medication is sustained long-term.
Pharmaceutical companies continue to call for a "chronic disease" model—offering medication alongside ongoing medical and behavioral support.
Update 1/8/26, 12:55 p.m. ET: This article was updated with comment from Eli Lilly and Company and Novo Nordisk
View 0 Comments
Submit Correction
View Editorial & AI Guidelines