Weight Loss Drugs: Muscle Loss Trade-off?

A new analysis indicates that tirzepatide, a GLP-1 drug, may result in more significant weight loss compared to semaglutide. However, this greater fat reduction comes at the cost of increased lean body mass loss, including muscle and connective tissues. The study, which analyzed data from thousands of patients, found that tirzepatide users lost an average of 2% more lean body mass over 12 months.

Researchers noted that approximately 10% of tirzepatide users who lost over 20% of their body weight also lost more than 5% of their lean body mass. This was true for fewer than 7% of semaglutide users achieving similar weight loss. Decreased exercise tolerance was linked to greater lean body mass loss in both groups, but to a more pronounced extent in those using tirzepatide.