Fentanyl test strips miss deadly opioid stronger than fentanyl detected in Los Angeles County

First county detection confirmed

The Los Angeles County Department of Public Health said a fatal overdose in February marked the first verified finding of cychlorphine in the county’s illicit drug supply. The discovery has prompted concern that the potent opioid could spread locally.

Cychlorphine, also known as N-propionitrile chlorphine, was first identified in the U.S. illicit drug market in 2024. The department says it has since been detected in 19 states, with detections more common in other parts of the country.

Testing limits raise risks

Health officials describe cychlorphine as substantially more potent than fentanyl, but have not specified how much stronger it is. The drug can cause severe respiratory depression, in which breathing slows dangerously or stops.

Conventional fentanyl test strips do not identify cychlorphine. It may be mixed unknowingly into other illegal drugs, and combining it with alcohol, prescription opioids, sedatives or other substances can make an overdose more dangerous.

Authorities say it has been found in powders, counterfeit prescription pills, liquids and rock-like crystals. The Food and Drug Administration has not approved cychlorphine for medical treatment.

Naloxone and local resources

Naloxone, used to reverse opioid overdoses, can also work against cychlorphine, officials say. Multiple doses may be needed, and the medication is available as a nasal spray or injection.

People can obtain naloxone from pharmacies, medical providers, public health centers and local Community Health Stations. Drugcheckingla.com offers testing results in about 15 to 20 minutes. For substance use disorder treatment resources, residents can visit SUDHelpLA.org or RecoverLA.org, or call the county Substance Abuse Service Helpline at 800-854-7771.