Semaglutide treatment in obese mice reduces skeletal muscle mass by approximately 15–20% without impairing maximal isometric muscle force under steady-state conditions, indicating a dissociation between muscle size and strength during pharmacologic weight loss.

When the body receives a drug that mimics a hormone reducing hunger, it takes in less food, which tells muscle stem cells to pause making new muscle fibers. Even though the muscle gets smaller, the existing fibers become more efficient at generating force, so strength stays the same. The muscle doesn't lose its ability to contract hard, even though it has less tissue.