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Until now, just two companies have dominated the obesity-treatment market: Denmark’s Novo Nordisk A/S and its US rival Eli Lilly & Co. Ozempic and Wegovy, made by Novo, are on track to become the world’s bestselling drug franchise in 2025, and Zepbound and Mounjaro, made by Lilly, are growing fast. But the year will also start to show how soon the weight-loss duopoly will face serious challengers.
Results from dozens of midstage patient trials of medications for obesity and related diseases are due in 2025, according to researcher Airfinity Ltd. The slew of data, from both upstarts and industry heavyweights, will help determine the options available in coming years. Drugmakers are aiming to offer medicines that can be taken less frequently, spur greater weight loss or cause fewer side effects.
Despite opposition to such medications by Donald Trump’s nominee for secretary of health and human services, Robert F. Kennedy Jr., Airfinity says as many as a dozen new obesity drugs might appear by 2027. The market by then could approach $50 billion annually, according to Bloomberg Intelligence.
Given the 1 billion-plus people with obesity worldwide, Novo says there’s ample room for the competition. “This is not one big homogeneous market,” says Chief Financial Officer Karsten Munk Knudsen. Patients need “different products for different motivations and different complications.” Dan Skovronsky, chief scientific officer at Lilly, says teams at various companies working to “out-innovate each other” will push everyone to improve their offerings.
The bar is high for the new medicines, as became clear when Amgen Inc. in November 2024 released trial results for its MariTide. The drug can be administered with a single monthly injection, versus weekly for current shots, and people who took it lost a fifth of their body weight in a year. But investors found the results too similar to what’s available now, and Amgen’s shares plunged. “It seems like folks are demanding something greater than Eli Lilly or Novo,” says Kazi Helal, an analyst with research company PitchBook.
The leaders are doing their best to stay ahead. Retatrutide, Lilly’s next-generation shot, showed an average 24% weight reduction after 48 weeks of treatment in a midstage study released in 2023. And Novo says its CagriSema might help patients shed a quarter of their weight.
While many coming compounds work similarly to what’s already on the market, technologies on the horizon are far more exciting, says Novo scientific adviser Lotte Bjerre Knudsen. She championed early versions of the drugs three decades ago, eventually figuring out how to make a compound that mimics a gut hormone and stays active long enough to have an effect. With the field developing so rapidly, she’s eager to see the range of diseases beyond weight and diabetes that the new drugs might treat. “It’s so difficult to predict,” Knudsen says. “What really excites me is more to take many things forward and figure out which ones are the best.” —With Madison Muller