Bimagrumab is a monoclonal antibody that blocks activin type II receptors, inhibiting myostatin to promote muscle growth while reducing fat mass. It has shown meaningful results in sporadic inclusion body myositis — a disease previously lacking effective treatment — and in sarcopenia. It also improves body composition and insulin sensitivity in obese type 2 diabetics. A key emerging application is its use alongside semaglutide (Ozempic/Wegovy), where up to 40% of GLP-1-driven weight loss comes from lean muscle mass. Bimagrumab may preserve that muscle. Subcutaneous delivery now matches intravenous efficacy, improving practical use. This review compares bimagrumab to other myostatin inhibitors and evaluates it against dual incretin therapies.
