Gray-market peptides: what independent testing can tell us

An October 9 JAMA news article put gray-market retatrutide in the spotlight. An Australian study tested three products labeled 10 mg of retatrutide: all three contained it, at measured amounts of 5.13, 19.0 and 16.5 mg. One Australian alert found semaglutide in a product sold as retatrutide; another described six liver-injury cases without establishing the cause. A Reddit preprint identified 13,589 accounts reporting use. None of this shows how often problems occur across the market. Inside: what identity, purity, quantity, endotoxin, microbial and heavy-metal tests each measure, three testing services compared, and what "research use only" means. Study: Drug and Alcohol Review, 2026.