WASHINGTON — Federal officials are warning about a powerful synthetic opioid appearing more often in the U.S. drug supply that can be up to 10 times more potent than fentanyl.
The White House Office of National Drug Control Policy (ONDCP) has issued a national drug threat notice for cychlorphine, a drug that has been linked to at least 55 deaths. The drug has been identified in states across all four U.S. Census regions, with the highest prevalence reported in Ohio, Texas and Tennessee.
Earlier this year, the Drug Enforcement Administration also warned about cychlorphine. According to the Center for Forensic Science Research and Education, the drug was first detected in mid-2024 but has been identified with increasing frequency since mid-2025.
In 2025, 106 reports of cychlorphine were identified across 10 states, compared to just one report in 2024. The Knox County Regional Forensic Center reports the drug has been linked to at least 41 overdose deaths in Tennessee between July 2025 and February 2026.
Health officials warn that cychlorphine overdoses are more difficult to reverse. The ONDCP says multiple doses of naloxone may be needed, and urges emergency responders, healthcare providers, law enforcement and the public to be prepared and to seek immediate medical attention in suspected overdose cases.
Cychlorphine, also known as N-propionitrile chlorphine, is part of a growing class of synthetic opioids sometimes referred to as “orphines,” which includes drugs like brorphine, spirochlorphine and chlorphine.
