Weight Regain After Stopping Anti-Obesity Medications: A Growing Concern

New anti-obesity injection medications, such as Wegovy and Mounjaro, demonstrate effectiveness in weight loss, but research indicates that weight regain is rapid once treatment is stopped. This finding raises questions about the cost-effectiveness of these treatments, particularly for healthcare systems like the UK’s National Health Service (NHS).

Significant Weight Loss, But Not Permanent

Clinical trials have shown participants losing an average of 15 to 20 percent of their body weight while using medications like Wegovy and Mounjaro – results significantly better than those achieved through traditional diet and exercise programs. However, a recent study published in the British Medical Journal reveals that, on average, individuals regain all lost weight within 18 months of discontinuing treatment. This regain occurs approximately four times faster than weight creep following conventional weight loss methods.

Health Improvements Are Also Reversed

The rapid weight regain isn’t the only concern. Improvements in health markers, such as blood pressure, cholesterol levels, and blood sugar, also revert to pre-treatment levels when medication is stopped. This suggests that long-term or even lifelong employ of these medications may be necessary to sustain benefits.

Cost and Access Challenges

Currently, approximately 1 in 50 people in the UK use these treatments, with around 90% paying out of pocket at a monthly cost of between £120 and £250. More than half of individuals discontinue treatment within a year, primarily due to financial constraints. In France, Wegovy, Mounjaro, and Saxenda are authorized for obesity treatment but are not reimbursed by health insurance, making them inaccessible to many.

NHS Rollout and Equity Concerns

The NHS is gradually making these medications available, but currently only to individuals with a Body Mass Index (BMI) greater than 40 and at least four obesity-related health conditions, such as high blood pressure. This restrictive criteria excludes many who could benefit unless they can afford private treatment. A British Medical Journal investigation in January 2026 found that one in five local areas still lacked a functional NHS pathway for Mounjaro, despite a national mandate for wider access.

Cost-Effectiveness Under Scrutiny

The National Institute for Health and Care Excellence (NICE) approved the use of these drugs within the UK public health system based on cost-effectiveness calculations assuming two years of treatment followed by weight regain three years later. However, new data indicates that weight regain occurs much faster, and health improvements are also lost within the same timeframe. This necessitates a reevaluation of the long-term cost-effectiveness of these medications.

Alternative Weight Management Strategies

For individuals who do not meet the strict NHS criteria, or for whom cost is a barrier, traditional weight management programs remain viable options. Total diet replacement programs, involving nutritious soups and drinks, can achieve weight loss comparable to medication at a significantly lower cost. Group weight loss programs, such as Weight Watchers and Slimming World, offer smaller average weight losses but may have a favorable cost-effectiveness ratio and potentially save the NHS money.

The Future of Obesity Treatment

These new anti-obesity drugs highlight the urgent need for effective weight loss solutions. However, a clear evaluation of cost-effectiveness is crucial. Increasing access to affordable weight management programs and ensuring equitable access to medications through the NHS, as prices potentially decrease with patent expirations and the development of oral formulations, will be essential for improving public health.