What to know about cychlorphine, the synthetic opioid 10 times stronger than fentanyl

Multiple states have raised the alarm in the past month about cychlorphine, a synthetic opioid tied to several dozen recent overdoses that is far stronger than fentanyl.

Cychlorphine is part of a new class of synthetic opioids making their way into the U.S. illicit drug supply. The drug has never been approved for use in humans. Like fentanyl, cychlorphine is being mixed in with other street drugs, but it is not detectable through fentanyl test strips, making it even more dangerous.

Narcan is still believed to be effective at treating an overdose caused by cychlorphine. 

When reached for comment, the Drug Enforcement Administration said in a statement to The Hill, “In April 2024, N-propionitrile chlorphine was first reported in Florida by a DEA laboratory. Through the end of February 2026, DEA laboratories have identified this substance in 22 samples.” 

In East Tennessee, cychlorphine has been linked to 19 overdose deaths; the Gallia County Health Department in Ohio issued an overdose alert this week; and the Kentucky Office of Homeland Security sent out a public warning about the drug last month.

The Center for Forensic Science Research & Education (CFSRE) issued a public alert at the end of January on the spread of cychlorphine, or N-propionitrile chlorphine. 

“In vitro pharmacology data show this drug to be approximately 10x more potent than fentanyl,” the CFSRE’s alert stated. “The positivity of N-propionitrile chlorphine, specifically in fatal drug........

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