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.

Eli Lilly said on Wednesday it had sued four compounders for selling unapproved products containing tirzepatide, after a U.S. judge last month blocked pharmacies from making copies of its weight-loss and diabetes medicines.

Big Pharma has put a Houston pharmacy squarely in the crosshairs of its quest to weed out copycat versions of wildly popular diabetes and weight loss drugs. Eli Lilly, the maker of the diabetes drug Mounjaro and weight loss drug Zepbound,