The University of Utah has published a study in Cell Metabolism, which found that weight loss drugs like Ozempic and Wegovy may affect more than just fat, raising questions about muscle strength and organ size after significant weight loss. The study, published in the journal Cell Metabolism, revealed “unexpected effects,” highlighting that lean mass, or body weight that isn’t fat, dropped about 10%. Most of the loss came from non-muscle tissues, particularly the liver, which shrank by nearly half. Some skeletal muscles lost around 6% of their size, while others remained unchanged. Despite relatively small changes in muscle size, certain muscles became weaker, which could be especially concerning for adults over 60, who already face higher risks of muscle loss and reduced mobility. The findings challenge the assumption that lean mass loss comes mainly from skeletal muscle and point to changes in metabolically active organs, such as the liver, which can shrink during healthy weight loss without harming function. Further human studies are necessary to determine whether similar effects occur in humans and whether they pose health risks.
A study suggests that semaglutides may decrease muscle size and strength.
