Two big drug companies, Novo Nordisk and Pfizer, are competing to buy a smaller company called Metsera, which is developing new treatments for obesity. Novo Nordisk has offered to buy Metsera for $6.5 billion upfront, with the possibility of paying up to $9 billion if certain conditions are met. Pfizer had previously made its own offer to buy Metsera, but Novo Nordisk’s offer is higher. Metsera has told Pfizer that Novo Nordisk’s offer is better, which gives Pfizer four days to make a higher offer if they want to. Pfizer has said that Novo Nordisk’s offer is trying to unfairly stop competition. Both companies are trying to improve their position in the obesity treatment market, which is expected to grow to $100 billion a year by 2030. Novo Nordisk was the first to market with obesity drugs like Victoza and Wegovy, but has since lost some ground to a competitor called Eli Lilly. Eli Lilly’s obesity drug, Zepbound, had sales of $3.6 billion in the third quarter of 2025, and their diabetes drug Mounjaro, which has the same active ingredient as Zepbound, had sales of over $10 billion, making it the world’s best-selling medicine. Novo Nordisk has had some setbacks with their own obesity drugs, and Pfizer has also had problems with their obesity drug candidates. Buying Metsera would allow both companies to improve their position in the obesity treatment market. Novo Nordisk’s offer is risky because they have to pay $6.5 billion upfront, even if the deal doesn’t go through. Pfizer has said that Novo Nordisk’s offer may have problems with regulations and could be blocked by the U.S. government. It’s unclear if the U.S. government would block the deal, but Metsera’s lawyers seem to think that the deal structure is acceptable.