New Drug May Reduce Muscle Loss in Weight Loss Injections

A new drug called apitegromab may help prevent muscle loss in patients using weight loss injections like Wegovy and Mounjaro, according to a recent study published in Nature Medicine. The research found that participants taking apitegromab alongside tirzepatide (Mounjaro) lost significantly less lean mass compared to those taking tirzepatide with a placebo, despite similar overall weight loss. The study involved 102 adults, with half receiving apitegromab and the other half a placebo. After six months, those taking apitegromab lost around 1.9 kg less lean mass than the placebo group. Previous studies have shown that up to a third of the weight lost from these injections comes from muscle and bone rather than fat. Apitegromab works by blocking myostatin, a protein that inhibits muscle growth. Researchers found that lean mass accounted for 14.6% of total weight loss in the apitegromab group compared to 30.2% in the placebo group. Experts note that while the findings are promising, more evaluation is needed before recommending the drug for widespread use. The drug is currently only available in clinical trials and is administered via intravenous infusion, though the manufacturer is exploring a self-injection option. Users of GLP-1 drugs like Ozempic and Wegovy have reported concerns about muscle loss and body shape changes, including the so-called "Ozempic butt." Health experts emphasize the importance of a balanced diet and exercise, including strength training, to mitigate muscle loss. Apitegromab is also being explored for other muscle-related conditions, such as spinal muscular atrophy.