New Delhi, 17 May 2025: A groundbreaking study from the University of Oxford has unveiled concerning findings about the long-term efficacy of popular weight-loss injections, such as Wegovy and Mounjaro. While these medications have been celebrated for their rapid weight-loss results, the research indicates that the benefits may be short-lived once the treatment ceases.
Rapid Weight Regain Post-Treatment
The Oxford study, presented at the European Congress on Obesity, analyzed data from 11 clinical trials involving over 6,000 adults. Participants who used GLP-1 receptor agonists like semaglutide (Wegovy) and tirzepatide (Mounjaro) experienced significant weight loss—averaging 16.1 kg (35.5 lbs). However, upon discontinuation of the medication, these individuals began regaining weight at a rate of approximately 0.8 kg (1.8 lbs) per month, returning to their original weight within 1.7 years.
In comparison, those who ceased older medications such as liraglutide (Saxenda) regained weight even faster, typically returning to their baseline weight in just under a year.
Understanding the Underlying Causes
GLP-1 receptor agonists function by mimicking the glucagon-like peptide-1 hormone, which suppresses appetite and slows gastric emptying, leading to reduced food intake. When the medication is stopped, the body’s appetite regulation mechanisms revert to their pre-treatment state, often resulting in increased hunger and caloric intake.
Additionally, these medications improve metabolic functions and blood sugar control. Discontinuation can lead to a reversal of these benefits, potentially causing blood sugar spikes and cravings for high-calorie foods, further contributing to weight regain.
The Necessity of Lifestyle Modifications
Experts emphasize that while weight-loss injections can be effective tools, they should not be viewed as standalone solutions. Dr. Susan Jebb, co-author of the Oxford study, stated, “These drugs are very effective at helping people lose weight, but the regain after discontinuation is significantly faster than what we observe after diets.”
Incorporating sustainable lifestyle changes—such as a balanced diet, regular physical activity, and behavioral support—is crucial for maintaining weight loss achieved through pharmacological means.
Potential Side Effects and Risks
Beyond weight regain, GLP-1 receptor agonists are associated with several side effects. Common adverse effects include nausea, vomiting, diarrhea, and constipation. Some users have reported cosmetic concerns like “Ozempic face,” characterized by facial fat loss leading to a gaunt appearance.
More severe complications, though rare, have been documented. For instance, a UK woman experienced a life-threatening episode after injecting herself with a counterfeit weight-loss jab purchased online, which was later found to contain insulin.
Guidelines and Recommendations
Given the potential for rapid weight regain and side effects, UK health guidelines recommend limiting the use of GLP-1 receptor agonists to a maximum of two years. Healthcare providers are encouraged to develop comprehensive weight management plans that include dietary counseling, physical activity, and psychological support to enhance the sustainability of weight loss.
The Oxford study underscores the importance of viewing weight-loss injections as part of a broader, multifaceted approach to obesity management. While these medications can offer significant short-term benefits, their long-term efficacy is contingent upon continued use and the integration of healthy lifestyle practices. Patients and healthcare providers must engage in informed discussions to weigh the benefits and risks, ensuring that weight-loss strategies are both effective and sustainable.
