Federal Officials Warn EMS Agencies About Emerging Synthetic Opioid Threat

Federal public safety officials are warning EMS agencies and clinicians about cychlorphine, an emerging synthetic opioid that has been linked to at least 55 deaths nationwide.

The National Highway Traffic Safety Administration Office of EMS and the White House Office of National Drug Control Policy issued the alert after cychlorphine was identified in the illicit drug supply across multiple states and regions of the country.

According to The White House Office of National Drug Control Policy, ONDCP, cychlorphine, also known as N-Propionitrile Chlorphine, is part of a class of synthetic opioids that also includes substances such as brorphine, spirochlorphine and chlorphine. Federal officials said the drug is especially concerning because it may be up to 10 times more potent than fentanyl.

Officials said cychlorphine has been found mixed with fentanyl, methamphetamine, bromazolam, cocaine and other illicit substances, but has also been detected on its own. That creates added danger for people who may not know what they are taking, as well as for first responders and medical providers treating overdoses.

Another major concern is detection. ONDCP said cychlorphine is not detected by drug test strips or routine hospital opioid urine screens, making it harder to identify during overdose responses or clinical care.

In 2025, federal officials said 106 reports of cychlorphine in the drug supply were identified in 10 states across all four U.S. Census regions. Reports were most concentrated in the South, Midwest and Northeast. The Knox County Regional Forensic Center in Tennessee recently reported that cychlorphine had been linked to at least 41 overdose deaths in Tennessee between July 2025 and February 2026. Nationally, officials said at least 55 deaths have been linked to the substance between 2025 and 2026.

Public safety officials are urging EMS providers, clinicians, law enforcement and the public to remain aware of the emerging threat. Because of the drug’s reported potency, overdose patients may require multiple doses of naloxone.

Officials recommend that the public avoid illicit substances, call 911 immediately if someone may be overdosing, and seek medical care right away following a suspected exposure.

EMS agencies and clinicians are also being encouraged to share information with public health and public safety partners as federal agencies continue tracking the spread of the substance.