Cotton, Schiff and Other Senators Warn FDA That Knockoff Weight-Loss Drug Retatrutide Is Flooding the Internet

A bipartisan group of nine senators is pressing the Food and Drug Administration to crack down on online sellers who use "for research use only" labels to sell unapproved drugs to Americans, pointing to a surge in knockoff versions of the experimental weight-loss drug retatrutide.

"We are concerned that 'for research use only' has become a dangerous loophole that undermines the FDA's authority," the senators wrote in an Oct. 14 letter to Acting FDA Commissioner Kyle Diamantas. The letter was led by Sen. Jim Banks (R-Ind.) and signed by Republican Sens. Tom Cotton, Ted Budd, David McCormick, Jon Husted and Todd Young and Democratic Sens. Martin Heinrich, Adam Schiff and Andy Kim.

What the Senators Say About Retatrutide

Retatrutide is in phase 3 clinical trials and has not been approved by the FDA, the letter says. Yet "many online vendors are already selling poor-quality retatrutide to Americans, and many of these companies source their APIs from unregulated manufacturers in China," the senators wrote, referring to active pharmaceutical ingredients.

According to the letter, America's Poison Centers reported a 265% increase in poisonings related to illicit retatrutide in the first four months of 2026 compared with the last four months of 2025. The senators added that some products sold as retatrutide "contain no retatrutide at all."

FDA Warning Letters

The FDA has sent warning letters to at least seven companies that labeled retatrutide "for research use only" while promoting it for obesity and diabetes, and to more than a dozen others selling the unapproved drug, the letter says.

What the Senators Want

The senators praised those enforcement efforts but urged the FDA to work more closely with Customs and Border Protection, saying the sellers' foreign supply chains "rely on concealment, falsified paperwork, and deliberately mislabeled shipments." They asked for a briefing on how widely the label is misused and what the FDA is doing about it.

Sources: Sen. Jim Banks press release: https://www.banks.senate.gov/news/press-releases/banks-urges-fda-to-crack-down-on-illicit-research-use-only-drugs/ ; Senators' letter to the FDA (Oct. 14, 2026, PDF): https://dl.dropboxusercontent.com/scl/fi/eaeulrk1plwq3ff5e9gar/2026.10.14-Senators-Letter-to-FDA-re-For-Research-Use-Only-Labeling.pdf?rlkey=9vjj3ateafudmlanlmwub60ga&dl=1