Semaglutide impacts skeletal muscle to a similar extent as caloric restriction in mice with diet-induced obesity.

People using GLP-1 agonists for weight loss lose more muscle mass than those who lose weight without medications.

In mice that became obese from their diet, stopping semaglutide or calorie restriction causes muscle mass and strength to fully recover within six weeks, and body fat and lean mass return to what they were before treatment.

In obese mice, semaglutide lowers total energy use as much as eating fewer calories, even though it causes more fat loss; this suggests the drop in metabolism is due to loss of lean tissue, not the drug itself.

In mice with obesity caused by diet, 4 weeks of semaglutide treatment causes the same loss of muscle mass and strength as a calorie-restricted diet with the same number of calories, even though semaglutide leads to more total weight and fat loss.

In mice with obesity caused by diet, semaglutide leads to more fat loss and total weight loss than eating the same number of calories without the drug, over four weeks.

In obese mice, semaglutide increases the activity of specific genes linked to muscle breakdown in skeletal muscle, while an identical calorie-restricted diet does not increase these genes, even though both treatments cause the same amount of muscle loss.