Eli Lilly, the maker of blockbuster weight loss and diabetes drugs Zepbound and Mounjaro, said it will invest an additional $27 billion to build four new manufacturing plants in the United States, shoring up domestic manufacturing as President Donald Trump threatens new tariffs on pharmaceuticals.

Eli Lilly said Wednesday it will build three manufacturing plants in the United States to make the key raw ingredients in its medicines, a push to bring home a critical part of the pharmaceutical supply chain that largely comes from foreign sources.