The two biggest weight-loss drugmakers have lost $252bn in value this year, as investor enthusiasm for obesity treatments wanes and Donald Trump’s tariff and price-cut threats weigh on the pharmaceutical sector.

The pricing of weight-loss and diabetes drugs like Lilly’s Zepbound and Mounjaro, and Novo’s Wegovy and Ozempic, is a pressure point for investors. Price erosion is a major worry amid increasing competition— including from knockoff versions of the drugs provided by telehealth pharmacies and coming patent expirations.

Eli Lilly will significantly increase the price of its weight-loss drug Mounjaro in the United Kingdom in a bid to bring down prices in the United States after weeks of pressure from the Trump administration.