A recent study suggests that apitegromab, a monoclonal antibody, may help preserve lean body mass during weight loss treatments using GLP-1 medications like tirzepatide, which is found in Mounjaro. While these medications are effective for weight loss, they can lead to a significant reduction in lean body mass, accounting for 25-40% of total weight loss. The trial involved 102 participants, with half receiving apitegromab alongside tirzepatide and the other half receiving a placebo with tirzepatide. Results showed that those on apitegromab lost an average of 1.6kg of lean mass, while the placebo group lost 3.5kg, resulting in a 55% greater retention of lean mass. Despite the promising results, experts caution that the study's small size and short duration necessitate larger trials to confirm benefits and safety. Additionally, they recommend that individuals using these medications should engage in physical activity to help maintain muscle mass.