Research indicates that individuals often regain weight lost although using GLP-1 medications, potentially regaining all lost weight within 20 months of stopping treatment, according to Dr. Jack Mosley.
The medications, including semaglutide (Ozempic and Wegovy) and tirzepatide (Mounjaro), work by reducing appetite and cravings, making the dieting process easier. However, Dr. Mosley cautioned against viewing these drugs as a “quick fix,” emphasizing that the rebound effect can be significant. “Although the weight loss is real with the weight-loss medications, so is the rebound,” he stated on Instagram. A 2026 study highlighted that weight regain occurs “between four and up to eight times faster” after discontinuing GLP-1s compared to traditional dieting.
Dr. Mosley, a GP registrar and son of the late Dr. Michael Mosley, has released a book titled Food Noise addressing healthy living alongside these medications. He noted his father had expressed concerns about the management of these drugs and the proliferation of online pharmacies offering them. Dr. Mosley emphasized that the drugs are “designed for people who have a BMI over 30 or women over 27 with an obesity-related disease,” and cautioned against their use for minor weight loss.
To mitigate weight regain, Dr. Mosley stresses the importance of establishing “sustainable healthy eating habits and lifestyle changes” while on the medications. He describes the drugs as “soundproof ear defenders,” reducing “food noise” and appetite, but emphasizes they are a tool that must be used in conjunction with other strategies for long-term success. He also warned that some online pharmacies may prescribe higher doses to increase profits, potentially leading to more significant side effects.
Dr. Mosley’s concerns echo broader discussions about the long-term efficacy of GLP-1 medications. While effective for some who have struggled with traditional dieting, the demand for sustained lifestyle changes remains paramount to prevent weight regain and maintain positive cardio-metabolic health markers.
