A significant new study has revealed that popular weight loss injections, including Mounjaro and Wegovy, trigger substantial muscle loss, affecting even facial features. These drugs, currently used by over 2.5 million people in the UK, have previously been shown to help obese patients lose up to a fifth of their body weight. However, the comprehensive report, which reviewed health data from thousands of patients, found that two-thirds of users also experienced a loss of crucial muscle mass. Experts largely attribute this muscle degradation to the phenomenon dubbed 'Ozempic-face,' where users' faces appear hollowed out and gaunt, with prominent cheekbones.

The findings of this review, set to be presented at the American College of Physicians' Internal Medicine Meeting in San Francisco, underscore the serious implications of rapid weight loss. Researchers are now issuing warnings for users to actively take measures to prevent muscle loss, which can lead to severe complications, including potentially life-threatening falls. Dr. Charlotte Suetta, a geriatric consultant at Copenhagen University Hospital, emphasized the importance of a holistic approach: "Treatment should be paired with strategies likely to preserve muscle health, especially resistance exercise and adequate protein intake."

The aesthetic changes associated with 'Ozempic face' are linked more to the speed and composition of weight loss than to the medication itself, as explained by Dr. Ruby Aktar, a neuroscientist and weight-loss expert at Queen Mary University of London. She states, "When weight is lost quickly, the body doesn’t just draw from fat stores, it can also break down lean muscle and the structural fat that supports areas like the face." This rapid depletion can leave individuals not only looking gaunt and malnourished but also at increased risk of frailty as they lose bone and muscle mass alongside fat. Dr. Suetta further cautioned that for older adults, preserving muscle is critical, as it directly impacts mobility, reduces the risk of falls, combats frailty, and helps maintain an independent life.

Celebrities have also openly discussed their experiences with these weight loss drugs. Sharon Osbourne, for instance, admitted in 2024 to feeling "too gaunt" and "too skinny" after taking the injections, confessing to difficulties in regaining weight. Similarly, pop star Robbie Williams revealed his use of GLP-1s, stating he was diagnosed with 'type 2 self-loathing.' Meghan Trainor also publicly shared her use of Mounjaro to achieve substantial weight loss, which she complemented with "huge lifestyle changes," including working with a dietician and personal trainer to manage her diabetes and slim down.

Beyond the immediate effects, the long-term implications of GLP-1 drugs also raise concerns. A landmark Oxford study published in January found that the majority of users tend to regain the lost weight within two years of discontinuing treatment, a rate much faster than traditional dieting methods. Experts warned that stopping the drugs not only reverses weight loss but also negates key heart benefits. These GLP-1 drugs work by mimicking hormones released after eating, but practitioners are urging that patients prescribed these medications should also receive comprehensive advice on diet, nutrition, and increasing physical activity to help preserve muscle mass.

Despite these concerns, GLP-1 drugs have fundamentally transformed obesity treatment, offering dramatic weight loss that was largely unachievable through diet and exercise alone. The National Institute for Health and Care Excellence (NICE) recently announced that over a million people with heart disease will be offered these injections on the NHS, marking the first time the drugs have been approved in the UK specifically to prevent heart problems, rather than solely for weight loss. While potential side effects such as nausea, vomiting, diarrhoea, and in rare cases, pancreatitis, exist, experts generally agree that the benefits significantly outweigh the risks for most patients. To mitigate muscle loss, experts continue to advise strength training and adherence to national guidelines, which recommend 150 minutes of moderate to vigorous exercise per week.