A study published in Cell Metabolism looks at the effects of semaglutide on skeletal muscle mass in mice.
Prof Lora Heisler, Director of Research, Rowett Institute, University of Aberdeen, Rowett Institute, University of Aberdeen, said:
“What may seem quite surprising is that nearly 30% of people in the UK are living with obesity. Obesity increases the risk for a range of medical conditions, including cancer, heart disease and type 2 diabetes. Losing weight, even by as little as 5%, can help reduce this risk. Wegovy mimics a hormone made in the gut called GLP-1 and it is associated with approximately 10% weight loss. Reducing obesity-associated diseases through weight loss benefits people living with obesity and the NHS.
“Weight loss, either through traditional dieting or Wegovy, reduces body fat but it also tends to reduce muscle mass to a smaller extent. This is because the body is using or burning stored energy.
“This study examines muscle loss associated with weight loss produced by Wegovy in mice. What is still an open question is whether the small degree of muscle loss observed in some patients taking Wegovy or similar medicines influences muscle strength or performance. The study by Funai and colleagues suggests that it might do in mice, but there needs to be huge helpings of caution taken alongside this as this study was conducted in mice, the change in muscle function was only found in one type of muscle, and consistently found with one dose of drug. Therefore, further research studies are needed in humans to understand the impact of Wegovy and other similar medications on muscle loss, strength, and performance.
“Preventing muscle loss associated with weight loss is a very active area of research aiming to improve patient outcome. Watch this space!”
‘Unexpected effects of semaglutide on skeletal muscle mass and force-generating capacity in mice’ by Takuya Karasawa et al. was published in Cell Metabolism at 16:00 UK time on Tuesday 5 August 2025.
Declared interests
Prof Lora Heisler: Prof Heisler is a consultant, sits on the Scientific Advisory Board and receives research funding from various pharmaceutical companies, but not Novo Nordisk (Wegovy).