SAN FRANCISCO, California: Eli Lilly has filed lawsuits against six U.S. companies it accuses of illegally selling black-market versions of its experimental obesity drug retatrutide, stepping up action against unauthorized sellers before the medicine has received regulatory approval.

The lawsuits target businesses including compounding pharmacies, medical spas and online sellers that allegedly marketed retatrutide products to consumers even though the drug remains under clinical development.

Retatrutide is currently in Phase 3 clinical trials for obesity, type 2 diabetes and other related conditions. Lilly said the compound has not been approved for human use by any regulator.

In June, the U.S. Food and Drug Administration said sales of retatrutide and other unapproved versions of GLP-1 products to consumers are illegal and that the products cannot lawfully be compounded.

"What is being sold on the black market is not a medicine – it is entirely unverified, unapproved and not worth the risk," Lilly Chief Medical Officer Dr. David Hyman said in a statement.

Lilly said demand for obesity treatments has fueled an online market for products claiming to contain weight-loss drugs. According to the company, some sellers have marketed retatrutide through websites, social media posts and businesses presenting themselves as medical providers despite sourcing products from unregulated manufacturers.

The drugmaker said it has referred more than 200 individuals and entities to the FDA, the U.S. Justice Department, state attorneys general, law enforcement agencies and professional licensing boards.

Lilly also called on social media and e-commerce platforms, payment processors, credit card companies, shipping firms and regulators to take stronger action against sellers of unapproved retatrutide products.

U.S. Customs and Border Protection told Reuters that it intercepted more than 690 shipments containing over 31,000 units of illicit GLP-1 drugs during fiscal 2025. In July, the figures more than doubled, with more than 1,400 seizures and nearly 90,000 vials intercepted.

"Every single time that someone takes one of these, they're exposing themselves to a huge amount of risk," said Lilly's Dr. Max Denning, Associate Vice President, Therapeutic Area Lead – Global Patient Safety Cardiometabolic Health.

The six lawsuits were filed against Aesthetic Envy Cosmetic Centers, Astra LLC, Legendary Peptides, Striker Pharmacy, Texas Peptides and Lone Star Peptide Co., according to Lilly.