New research indicates that individuals who come off new GLP-1 drugs like Wegovy and Mounjaro may regain lost weight far faster than those who end traditional diet and exercise programs.
Findings released in a leading medical journal demonstrates that while obese individuals often shed about a fifth of their body weight while on the medication, the weight comes back at an average rate of nearly a kilo each month after stopping.
"Individuals purchasing such drugs must be informed of the risk of rapid weight regain when the therapy concludes," cautioned researcher Dr. Susan Jebb.
This pace of recovery implies a return to pre-treatment weight in about 18 months.
Comparing Approaches
The study, which reviewed 37 of studies involving thousands of participants, contrasted the effects of the injectable medications with conventional dieting.
Scientists emphasize that people who lose weight through diet and exercise usually see a more gradual creep back—approximately 0.1 kg a month—after stopping.
The Reason for the Quick Rebound
Experts suggest the mechanism of the jabs accounts for the accelerated weight return.
These medications imitate a body's own chemical called glucagon-like peptide-1, which moderates feelings of fullness.
"Long-term administration of the hormone concentrations far above than the body's typical production could lead to the system to generate a reduced amount of its own natural hormone, and could reduce responsiveness to its actions," said Dr. Adam Collins, a dietetics specialist.
"Stopping of this GLP-1 'fix' leads to hunger is unsuppressed, making excessive eating far more likely."
A Chronic Issue?
The NHS recommend the injections for individuals with obesity-related medical conditions, alongside prescribed diet and exercise modifications.
A number of clinicians argue that, considering the significant potential of relapse, the treatment might need to be life-long.
This opinion is supported by drug manufacturers, who note that the findings "emphasize the long-term nature of excess weight," akin to managing conditions like hypertension.
Patient Accounts
Individuals who have stopped the jabs describe a sudden return of cravings.
"I experienced something that goes on and you become extremely hungry," said one woman.
This challenge is compounded if users have not established sustainable dietary or behavioural changes during treatment.
Growing Adoption
Figures show that millions of adults in the UK have tried weight-loss jabs in the last 12 months, with demand continuing to grow.
- Adoption is greater among females compared to males.
- The middle-aged demographic shows the greatest usage rates.
- Many access the medications through private prescriptions rather than the NHS.
Ultimately, clinicians caution that while these medications are effective tools for weight loss, they are not a permanent fix and lasting health benefits hinges on ongoing lifestyle support.
