A product sold in Australia as retatrutide, the most anticipated weight-loss drug not yet on any market, contained a high dose of semaglutide ↗ and no retatrutide at all.
That finding, from Australia's drug regulator, anchors a JAMA Medical News report ↗ published October 9. The report maps the gray market for two injectable obesity drugs that no regulator anywhere has approved: Eli Lilly's retatrutide ↗ and Novo Nordisk's zenagamtide. Both sell openly online, often labeled "for research purposes only" while the same listings give dosing instructions. Both are pushed by influencers across hundreds of TikTok videos and Instagram posts.
The lab numbers are the part worth reading twice. University of Queensland researchers tested three vials each labeled as 10 mg of retatrutide. One held about half the stated amount, one held about two-thirds more, and one held twice the label. Across the samples they also found traces of lead and small amounts of copper and zinc, all below levels the authors called harmful, and they did not test whether the products were sterile or free of the bacterial fragments that cause injection-site reactions and fever. So a buyer drawing up a dose has no way to know whether the syringe holds half the drug, double it, a different drug, or something with metal in it.
Why "research-grade" is the tell
Retatrutide is Lilly's triple agonist, hitting the GLP-1, GIP, and glucagon receptors at once. In the TRIUMPH trials it produced the largest weight loss of any drug in the class, around 24 percent at the top dose. That is exactly why a gray market formed around it before approval. Lilly does not plan to file with the FDA until the first quarter of 2027. That leaves a window where demand far outruns any legal supply, and sellers fill it with powder of unknown origin.
The "for research purposes only" label is the mechanism that keeps those sellers in business. It is a claim that the product is not for human use, which is what lets it ship without the manufacturing controls a drug requires. The dosing instructions on the same page give the game away. The FDA has sent 21 warning letters to retatrutide sellers since December 2024, including one to a business called Tex Peptides on August 24. Five weeks later its homepage still featured retatrutide. Enforcement that arrives by letter and does not stick is not much of a brake.
This is not Australia's first flag on the class. Its regulator earlier named five peptides being sold outside approved channels ↗, one of them a Phase 3 obesity drug, which is the same pattern a year on, now with lab assays attached. Zenagamtide, the newer of the two, has drawn no FDA warning letters yet, which reads less like a clean record than like a drug the agency has not caught up to.
The real drug, when it arrives, will come with a dose you can trust and a label that means what it says. The vials shipping today are a different product wearing the same name.