Eli Lilly is suing four telemedicine companies selling compounded versions of its blockbuster obesity drug Zepbound and its diabetes treatment Mounjaro, escalating its battle against unauthorized sellers,

Eli Lilly ( LLY 0.89%) has been growing its sales at a good clip over the past year. This is partly thanks to Zepbound, a weight loss medicine that's already generating more than $1 billion in quarterly sales, although it was approved only in late 2023.