Next-generation obesity drugs will work differently from Ozempic and Wegovy — aiming to deliver greater weight loss with fewer side effects.
Muscle loss is a big concern for people on anti-obesity medications such as semaglutide. These ‘GLP-1 agonists’ mimic a natural gut hormone — glucagon-like peptide 1 — to suppress appetite and regulate metabolism. But reducing calories leads to an energy deficit, which the body often makes up for by burning muscle. The experimental drug that Cook received, called bimagrumab, seems to counteract this muscle loss.
Obesity drugs: huge study identifies new health risks
It’s one of more than 100 anti-obesity drug candidates that are in various stages of development. The next wave of medications, which are likely to hit pharmacy shelves in the next few years, resemble drugs that are already on the market. But close behind are numerous therapies being developed specifically for their muscle-sparing weight-loss potential. Dozens more are aimed at different biological pathways and could redefine obesity treatment in decades to come.
“We’re working to create the next generation of healthy weight-loss solutions,” says Philip Larsen, who played a key part in the early development of GLP-1 drugs and is now chief executive of SixPeaks Bio, an obesity-focused start-up company in Basel, Switzerland.
The surge in anti-obesity drug development has been made possible by the blockbuster success of semaglutide and its rival drug tirzepatide — sold as Zepbound or Mounjaro. These drugs have unlocked the potential for a global market that is projected to surpass US$100 billion by the end of the decade.
But semaglutide and tirzepatide have limitations. They require weekly injections and frequently cause unpleasant side effects, with nausea, vomiting and diarrhoea being particularly common. Long term, the loss of muscle mass and the likelihood of weight regain after stopping therapy are also issues. What’s more, the drugs don’t work sufficiently for an estimated 10–30% of people who take them.
Emerging therapies aim to amplify weight loss, improve tolerability, ensure long-lasting effects and find options for a broader range of individuals (see ‘Next up in obesity drugs’). “We’re going to see that there are different medicines that work better for different groups of people,” says Louis Aronne, an obesity specialist at Weill Cornell Medicine in New York City who consults for drug makers.
