Eli Lilly’s experimental weight-loss drug retatrutide has yet to be approved by the FDA. But the buzz surrounding the effectiveness of the compound—commonly known at triple-G—has already triggered a booming black market for the injected treatment.
In response, Lilly has filed lawsuits against six companies in the United States, accusing them of selling illegal versions of retatrutide. The lawsuits are targeting compounding pharmacies, medical spas and online sellers who claim that the knockoffs are for “research-use only,” while selling them for human use, according to the Indianapolis drugmaker.
Additionally, Lilly said that it has reported more than 200 entities engaged in the illegal market to the FDA, the Department of Justice, state attorneys general, law enforcement and professional licensing boards. In more than 100 countries, Lilly also has uncovered 14,000-plus websites, advertisements, social media posts and product listings offering retatrutide, it said.
The lawsuits come two months after the FDA warned buyers and sellers about unapproved versions of retatrutide and other weight-loss drugs including Lilly’s tirzepatide, which is known commercially as Mounjaro or Zepbound, and Novo Nordisk’s semaglutide, known commercially as Ozempic or Wegovy.
While copycats may be labeled “for research purposes” or “not for human consumption,” they are being sold directly to consumers with dosing instructions included, the FDA said, adding that the products are of “unknown quality and may be harmful to their health.”
“We take the responsibility of evaluating the safety and efficacy of our investigational medicines seriously,” Lilly’s chief medical officer, David Hayman, M.D., said in a statement. “What is being sold on the black market is not a medicine—it is entirely unverified, unapproved and not worth the risk.”
As early as March of 2025, the FDA was warning (PDF) healthcare professionals about the illegality of compounded versions of retatrutide and the risks they could pose.
The companies Lilly is taking to court are California’s Aesthetic Envy Cosmetic Centers and five in Texas—Astra, Striker, Lone Star Peptide, Legendary Peptides and Texas Peptides.
The lawsuits are similar to those previously brought by Lilly to protect its weight loss products. In 2023, the company sued eight companies in five states that were either producing or selling compounded versions of Mounjaro. Less than a year later, Lilly followed with filings against six companies for false advertising.
Lilly plans to file for approval of retatrutide early next year. The compound has provided up to 29% weight loss in a phase 3 trial. Retatrutide targets three hormone receptors: GLP-1, GIP and glucagon.