Many individuals who stop taking weight loss medications tend to regain their previous weight within two years, according to a recent analysis of existing studies.
The rate of regain is notably quicker compared to those who lose weight through lifestyle changes like diet and exercise instead of relying on GLP-1 medications, as reported by researchers from the University of Oxford in a paper published in The BMJ journal.
GLP-1, short for glucagon-like peptide-1, is a hormone produced naturally in the body that signals to the brain and the gut that one feels full, reducing the urge to eat.
These weight loss medications imitate this hormone’s function, enhancing insulin secretion to lower blood sugar levels.
Additionally, they slow digestion, helping individuals feel satiated more quickly and for extended periods while also working in the brain to curb appetite.
GLP-1 medications, such as Ozempic, Wegovy, Mounjaro, and Zepbound, have shown significant effectiveness in weight loss.
However, researchers from the University of Oxford reviewed the findings from 37 studies that involved over 9,300 adults.
They found that people generally regain weight more quickly after discontinuing these medications compared to stopping behavioral weight loss strategies, indicating a difference of approximately 0.3 kg (0.7 pounds) per month.
“This isn’t a failure of the medications themselves; it reflects the chronic and relapsing nature of obesity,” commented Sam West, the study’s lead author from the University of Oxford. He emphasized the need for caution regarding short-term use without a broader strategy for weight management.
Adam Collins, an associate professor of nutrition at the University of Surrey who was not part of the study, deemed the paper as significant and timely. He pointed out that weight regain is a familiar issue in all weight loss methods, but it seems to be more pronounced with GLP-1 medications.
He proposed some reasons behind this phenomenon, suggesting that artificially elevating GLP-1 levels for extended periods might lead the body to produce less of its own GLP-1 and become less responsive to it.
This may not be problematic while taking the medications, but stopping them could make overeating more likely. He illustrated the challenge of suddenly discontinuing a medication, especially for those who relied heavily on GLP-1 drugs for weight loss instead of making lifestyle changes.
Marie Spreckley, an obesity researcher and public health nutritionist at the University of Cambridge, raised concerns about the study’s long-term conclusions being based on modeled projections rather than direct observational data. The follow-up period for halting treatment with these newer medications is roughly 12 months.
She noted that the implications of regaining weight within two years stem from extrapolated data, making comparisons with behavioral changes more suggestive than definite.
“In practical terms, these findings underscore that effective obesity management usually requires long-term strategies. If people stop taking the medication, they will likely need ongoing nutritional guidance, and healthcare systems should prepare for potential reductions in health benefits as weight is regained,” she added, calling for more research into effective long-term strategies for maintaining weight alongside medication use.
GLP-1 medications have gained popularity recently, with over 15 million Americans reportedly using them for weight loss.
Furthermore, a study released in early 2025 indicated that GLP-1 drugs, approved for various conditions like weight loss and diabetes, might also help reduce the risks associated with substance abuse disorders, psychosis, infections, and certain cancers or dementia.
Nonetheless, it’s essential to remember that while these drugs can suppress appetite and aid in fat reduction, they may also contribute to muscle loss.
Research has shown that anywhere from 15% to 60% of the weight lost during treatment can be lean muscle mass, leading to recommendations for users to engage in regular strength training to mitigate excessive muscle loss.
This is particularly crucial for individuals aged 65 and older, who are already vulnerable to age-related muscle mass, strength, and function decline.
