Do GLP-1 receptor agonists cause disproportionate muscle loss in people with MASLD?

In people with MASLD who take GLP-1 receptor agonists, the amount of muscle lost appears to align with the total weight lost — meaning if someone loses 10 pounds, about the same proportion of muscle is lost as fat, without a disproportionate drop in muscle mass. This pattern was consistent across multiple studies, and no case showed muscle loss that was unusually high compared to the total weight change. Muscle loss in this context is not unique to these medications — it’s a common part of weight loss, regardless of the method. What we’ve seen so far does not indicate that GLP-1 receptor agonists specifically target or accelerate muscle breakdown beyond what would be expected from losing weight.

We don’t yet know how factors like protein intake, exercise, or duration of treatment might change this pattern, because the evidence we’ve reviewed doesn’t explore those variables in depth. But based on what we’ve seen, the muscle loss observed is within the range of what typically happens during weight loss, and not something that stands out as a special risk tied to these drugs.

If you’re taking a GLP-1 receptor agonist and are concerned about muscle loss, focusing on adequate protein intake and staying active may help preserve muscle while you lose weight — just as it would with any weight-loss approach.