Medications like Ozempic and Wegovy have gained widespread popularity for their weight-loss benefits, but scientists are raising questions about their effects on muscle mass. A recent commentary in The Lancet by an international team of experts highlights a lack of research on how these drugs—specifically GLP-1 receptor agonists—might impact muscle tissue.
The authors of the commentary emphasize that GLP-1 agonists have brought substantial benefits for people worldwide. Initially approved for managing type 2 diabetes, these medications have shown potential for promoting weight loss and improving kidney and heart health. Even for individuals who do not experience weight loss, the drugs have shown benefits in reducing risks of stroke and cardiac arrest.
However, researchers have concerns about early findings on GLP-1 agonists. Preliminary studies indicate that weight loss from these drugs may result in slightly higher rates of non-fat tissue loss compared to weight loss achieved through lifestyle changes alone. Though a decrease in fat-free tissue does not necessarily confirm muscle loss, nor directly imply reduced strength or movement capability, scientists emphasize that long-term studies are needed to assess the full impact on muscle mass.
At present, there is no concrete data to confirm whether GLP-1 agonists contribute to muscle loss or physical frailty, the authors noted. This is due in part to a lack of studies specifically designed to answer these questions. The initial studies suggest that strength might not be directly impacted by weight loss on GLP-1 agonists, but strength represents just one facet of muscle function. Beyond movement, muscles are essential for various physiological processes, including metabolism, immune function, and the body’s response to stress and trauma. Muscle tissue also plays a critical role in glucose uptake in response to insulin, meaning that loss of muscle mass could have broader implications.
Researchers are particularly concerned that muscle loss might compound certain risk factors associated with GLP-1 agonists in some individuals, such as metabolic dysfunction, inflammation, low dietary intake, and limited physical activity.
To address these potential risks, the authors recommend that GLP-1 agonists be used strategically, alongside interventions in nutrition and exercise. Studies suggest that, after weight loss, some decline in skeletal muscle mass can be countered by increased protein intake and exercise. In fact, resistance exercise has been shown to reduce losses in fat-free mass by as much as 50 to 95 percent. This reinforces the idea that combining exercise and nutritional counseling with GLP-1 agonists could yield more favorable outcomes for patients.
It’s also worth noting that patients who stop using appetite-suppressing drugs like GLP-1 agonists tend to regain about two-thirds of their lost weight within a year. In a recent clinical trial, participants who engaged in supervised exercise programs maintained their weight loss more effectively. Researchers are also exploring ways to mitigate muscle loss through other drug treatments that could help preserve muscle tissue during weight loss.
Although concerns about potential muscle loss do not suggest that patients should stop taking GLP-1 agonists, the researchers stress the importance of understanding more about these drugs’ effects on muscle health. Given the critical role of muscle tissue in overall health, the authors advocate for further research to gain a clearer picture of GLP-1 agonists’ impact on muscle mass and to identify strategies for minimizing any negative effects.
