The combination of a GLP-1 receptor agonist and a myostatin pathway inhibitor reduces body fat while maintaining or increasing lean tissue mass.

Study: Bimagrumab plus semaglutide alone or in combination for the treatment of obesity: a randomized phase 2 trial

When people took both a weight-loss drug (semaglutide) and a muscle-protecting drug (bimagrumab), they lost more fat and kept more muscle than when taking just the weight-loss drug alone.

Study: Apitegromab for lean mass preservation during tirzepatide-induced weight loss: a randomized, double-blind, placebo-controlled phase 2 trial

When people took a weight-loss drug (tirzepatide) plus a muscle-protecting drug (apitegromab), they lost the same amount of weight as those on just the weight-loss drug — but kept much more muscle. The muscle drug helped stop the body from breaking down muscle while losing fat.

Study: Antibody blockade of activin type II receptors preserves skeletal muscle mass and enhances fat loss during GLP-1 receptor agonism

When mice took a weight-loss drug alone, they lost both fat and muscle. But when they took the weight-loss drug plus another drug that helps muscles grow, they lost even more fat—while keeping all their muscle. So together, the drugs worked better than either alone.

Study: 1690-P: PG-110, a Novel Bispecific Antibody Targeting ActRII and Myostatin, Enhances Fat-Specific Weight Loss and Improves Bone Health in Combination with GLP-1 Agonist Therapy

When mice were given both a weight-loss drug and a muscle-protecting drug, they lost more fat but kept their muscle, unlike when they got only the weight-loss drug. This means the combo works better without hurting muscle.