A reporter bought two vials of a weight-loss drug off the internet, sent them to a lab, and got back results one chemist called “pretty terrifying.”
Quick Take
- CBS News purchased two samples marketed as retatrutide, an experimental drug still in Eli Lilly clinical trials, and sent them for independent lab testing.
- One lab found phenylacetic acid, a filler, instead of verified retatrutide. Another found 13 colonies of bacteria in a sample meant for injection.
- The vials carried a “research use only, not for human consumption” label even though they were marketed for people to inject.
- The Food and Drug Administration (FDA) has already issued multiple warning letters calling retatrutide products unapproved and illegal to sell.
- Eli Lilly says no retatrutide drug has been approved for human use and calls black-market versions “entirely unverified, unapproved.”
What the Lab Found in the Vials
CBS News bought two products sold online as retatrutide, a weight-loss drug Eli Lilly is still testing in clinical trials. Neither sample matched the real thing. Both matched a basic lab-made standard, not the actual drug being studied in Lilly’s trials, according to the chemist who analyzed them.
One tested sample contained phenylacetic acid, which the analyst identified as a filler rather than an active ingredient. A separate lab found something worse. Carl Ross, who directs development work at the University of Iowa’s Center for Biocatalysis and Bioprocessing, counted 13 bacterial colonies in a sample meant to be injected into the body. He warned that injecting contaminated material like this could cause an infection.
The vial itself carried a warning label reading “Research use only, not for human consumption.” That label sat alongside marketing aimed squarely at consumers looking to lose weight, a gap between the fine print and the sales pitch that has become common across this corner of the internet.
Why Regulators Call This an Unapproved Drug
The FDA has sent warning letters to sellers of retatrutide products, stating plainly that these are unapproved new drugs with no approved application on file. One letter, sent to the company Swisschems, cited violations of federal drug law covering the sale of unapproved and misbranded drugs. These letters make clear that no version of retatrutide sold to consumers has cleared FDA review.
The agency has separately warned that products labeled “for research purposes” or “not for human consumption” are often sold directly to people anyway, sometimes with dosing instructions included. That mismatch between the label and the real-world use is exactly what shows up in these retatrutide sales, and it is a pattern the FDA has flagged across the broader unapproved GLP-1 drug market, not just one product.
Eli Lilly Distances Itself From Black-Market Vials
Eli Lilly, the company actually developing retatrutide through clinical trials, has pushed back hard on the black-market version of its own drug. Chief Medical Officer David A. Hyman said retatrutide is being rigorously studied in formal trials, while material sold online is “entirely unverified, unapproved.” Lilly has publicly called on online platforms, payment companies, and regulators to shut down the black market.
🇺🇸 A "miracle" weight loss shot from a Brooklyn bodega turned out to be fragrance filler and BACTERIA
CBS News bought retatrutide, an experimental drug Eli Lilly is still testing, from a clinic website, a gym and a corner store without ever talking to a doctor.
Lab tests showed… pic.twitter.com/dYvqFbMj25
— Mario Nawfal (@MarioNawfal) October 22, 2026
That statement matters because Lilly has every reason to protect its drug’s reputation, and it still confirms the core fact regulators and the lab testing point to: nothing sold on the open internet right now is the real, approved drug, because no approved version exists yet for anyone to buy.
A Pattern Already Familiar to Regulators
This is not a new problem. Counterfeit weight-loss pills have shown up for years with substituted ingredients, including a case where fake Xenical capsules were found to contain sibutramine, a drug pulled from the market for safety reasons. The FDA’s own guidance warns that illegal GLP-1 products can carry the wrong ingredient, too much, too little, or none at all.
Enforcement letters alone have not stopped the flow. A watchdog group tracking FDA warning letters since 2024 found that most sellers kept advertising retatrutide or similar peptide drugs even after receiving a formal warning, and most kept selling. For anyone searching retatrutide online today, the FDA record and this lab testing point in the same direction: buyer caution is not optional; it is the only protection currently available.
Sources:
cbsnews.com, fda.gov, citizen.org, investor.lilly.com
