Doctors say drugs that improve muscle mass could benefit older or infirm people at greater risk of falls and fractures

Popular weight-loss therapies like Novo Nordisk's Wegovy and Eli Lilly's Zepbound result in both fat and muscle loss.

About a dozen drugmakers are developing new weight-loss treatments aimed at preserving muscle, and industry analysts, clinical trial experts and doctors say they may also need to demonstrate additional health benefits beyond the numbers on a scale to get approved.