DEA Reports Fentanyl Mixtures With Other Drugs Raise Overdose Risks

The Drug Enforcement Administration issued an alert in mid-May stating that fentanyl is increasingly combined with other synthetic substances. The agency said these mixtures make the drug supply more unpredictable and lethal. The DEA stated that fentanyl is being added to a variety of synthetic drugs already on the market.

It listed xylazine, nitazenes, cychlorphine, and medetomidine as substances now appearing in combinations with fentanyl.

The DEA said many of these substances are not approved for human use and are often undetectable to users. Xylazine and medetomidine are veterinary sedatives. Nitazenes and cychlorphine are unregulated synthetic opioids. The agency noted that naloxone reverses opioid effects but does not reverse xylazine or medetomidine.

This leaves users at higher risk of lethal outcomes when these substances are present.

Seizure Trends Federal data show that U.S.

Customs and Border Protection seized almost half as much fentanyl in fiscal 2025 as in fiscal 2023. Roughly 85 percent of seizures occurred at ports of entry. CBP Commissioner Rodney Scott said in an April interview that cartels have shifted to powder form to reduce detection risk.

He said this change allows smugglers to move the substance with lower overhead. A November agreement between the United States and China aimed to stop exports of fentanyl precursors to Mexican labs. Following a recent summit, the White House said both countries highlighted the need to build on progress in ending the flow of precursors.