New drug to stop 'Ozempic butt' muscle loss side effect of obesity jabs
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- Apitegromab combined with Mounjaro preserved around 1.9kg (55%) more muscle mass over six months than a placebo in a 102-adult trial published in Nature Medicine, most of them women
- Lean mass made up just 14.6% of total weight loss in the apitegromab group versus 30.2% in the placebo group, body scans showed
- Apitegromab blocks a protein involved in muscle breakdown, is currently delivered only as an IV infusion in clinical trials, and its manufacturer is exploring a self-injection pen
- US research cited in the coverage estimates roughly a third of weight lost on GLP-1 drugs such as Ozempic, Wegovy, and Mounjaro comes from muscle rather than fat
- US plastic surgeons report a "noticeable uptick" in consultations over "Ozempic butt"—a deflated, saggy appearance linked to rapid loss of fat, muscle, and tissue volume
- Dr Marie Spreckley of Cambridge University called the findings "encouraging early evidence" rather than definitive proof and urged larger, longer studies to test effects on strength and long-term health
- Apitegromab is also being investigated as a treatment for spinal muscular atrophy and other muscle-wasting conditions
Why it matters: The trial enrolled only 102 adults over six months, so apitegromab remains years from clinical use in obesity—if it ever reaches that indication. If larger studies confirm the 55% muscle-preservation signal, it would directly target the tissue loss already driving GLP-1 users to plastic surgeons, potentially reshaping both obesity pharmacotherapy and the post-weight-loss cosmetic market.
