Eli Lilly sues to curb black-market sales of experimental obesity drug retatrutide

Eli Lilly announced it has filed six new lawsuits aimed at stopping black-market sales of its experimental obesity medicine retatrutide. The legal actions target online merchants, clinics, compounders and foreign firms that claim to offer the drug.

Retatrutide, described by Lilly as a "triple-G" therapy, remains in the research stage and the company does not expect to submit an FDA approval application until next year. Early studies have shown weight-loss results that rival bariatric surgery.

Lilly warned that products sold through the illicit market could be counterfeit, impure or incorrectly dosed, creating safety risks for patients. The company is seeking assistance from courts, regulators and law-enforcement agencies as concerns grow over unreviewed substances entering the market.