Eli Lilly sues two pharmacies making copycat Zepbound, Mounjaro

Eli Lilly is suing two pharmacies for compounding Zepbound and Mounjaro, claiming the companies are skirting the Food and Drug Administration's ban on the practice and luring people away from Lilly's medicines.

In lawsuits filed Tuesday in Delaware and New Jersey, Lilly alleges the two companies — Strive Pharmacy and Empower Pharmacy — are falsely marketing their products as personalized versions of the drugs that have been clinically tested and are made using stringent safety standards. Lilly argues these claims are turning people toward compounded drugs and away from its FDA-approved treatments.

Strive and Empower didn't immediately respond to CNBC's requests for comment.

Compounding pharmacies and outsourcing facilities were largely supposed to stop making their own versions of tirzepatide, the active ingredient in Lilly's weight-loss drug Zepbound and diabetes treatment Mounjaro, last month after the FDA determined the branded versions were no longer in shortage. Some continued compounding, tweaking the dosages and combining them with vitamins, distinctions that make them different from Lilly's drugs and potentially allow them to skirt the FDA's ban.

Lilly argues Strive and Empower are merely mass producing altered versions of tirzepatide rather than personalizing them. Branded drugs are allowed to be compounded at large scale when they're in shortage. Outside of that, custom versions can be made for unique situations, like if a person is allergic to an ingredient or can't take the form of the drug it's normally sold in.

Strive and Empower supply tirzepatide to popular telehealth sites, including Lavender Sky Health and Mochi Health. The companies didn't immediately respond to CNBC's requests for comment.

These lawsuits will be the first test of Lilly's ability to take on compounding pharmacies in court now that Zepbound and Mounjaro are off the FDA's shortage list. And they could provide a roadmap for Novo Nordisk, whose obesity drug Wegovy and diabetes treatment Ozempic generally can't be compounded after the end of May.