The primary engine behind the huge revenue expansion is its Mounjaro, powered by the active ingredient tirzepatide. The drug, sold as Mounjaro for type 2 diabetes and Zepbound for obesity, helped grow revenue by more than 56% year over year to $19.8 billion in the first quarter, and improved earnings per share (EPS) to $8.55, up 156% over the same quarter a year ago.

Those numbers don't reflect the impact that Foundayo, a daily GLP-1 pill, will have. The Food and Drug Administration (FDA) approved Foundayo on April 1 to treat adults with weight-related medical problems. The therapy will attract users who dislike needles and will likely be cheaper to manufacture than injectables.

The company is also seeing more pharmacy benefit managers reinstate Zepbound as a preferred drug, opening it up to more users.

2. Lilly is using its profits to broaden its portfolio