DETROIT, Michigan — The drugs on the street are getting more dangerous — and more unpredictable. Federal law enforcement is warning the public that fentanyl is increasingly being mixed with a new class of synthetic substances that can be more potent than fentanyl itself, render standard overdose treatments ineffective, and kill without warning.
The DEA’s Detroit Field Division issued a public safety advisory Tuesday identifying four substances now routinely found mixed into the illicit drug supply: xylazine, medetomidine, nitazenes, and cychlorphine. Two of those — xylazine and medetomidine — are veterinary sedatives not approved for human use. The other two are synthetic opioids operating largely outside existing drug regulations.
None of them can be detected by the person taking them.
“The illicit drug supply is more unpredictable and more lethal than ever before,” said Joseph O. Dixon, Special Agent in Charge of the DEA Detroit Field Division. “There is no way to know what is truly contained in a counterfeit pill or street narcotic.”
The stakes are not abstract. When xylazine or medetomidine is present in a drug, naloxone — the overdose reversal medication carried by first responders and distributed to the public — may not fully work. Those two substances are not opioids, meaning naloxone cannot reverse their effects. Nitazenes and cychlorphine may require multiple doses of naloxone to counteract. In the window between collapse and a full reversal, people are dying.
Xylazine also causes severe physical damage in people who survive. The drug has been linked to serious soft tissue wounds, deep infections, and prolonged sedation that can leave people incapacitated for extended periods.
The DEA has identified 22 unique nitazene compounds since 2020. Twenty-one are now classified as Schedule I controlled substances. New variants keep appearing as enforcement pressure on existing versions forces traffickers to introduce slightly altered chemical structures that fall outside current regulations — a cat-and-mouse cycle that authorities say is accelerating.
Dixon said the mixing is deliberate. “Drug traffickers continue to prioritize profits over human life by mixing fentanyl with dangerous synthetic substances that increase the risk of overdose and death,” he said.
Authorities are urging the public never to take a pill that was not prescribed and dispensed by a licensed pharmacy, to assume any street drug may contain fentanyl or other additives, and to carry naloxone while understanding it may not be enough on its own. Anyone witnessing a suspected overdose should call 911 immediately.
More information is available at DEA.gov/fentanyl and DEA.gov/onepill.