Deadly New Drug More Potent Than Fentanyl Found In LA County

LOS ANGELES, CA — A deadly synthetic opioid more potent than fentanyl has been detected in Los Angeles County's illicit drug supply for the first time, prompting a warning from public health officials.

The Los Angeles County Department of Public Health issued the warning after the county Medical Examiner identified the drug, known as cychlorphine, as a cause of death in a February 2026 case.

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The death marks the first confirmed presence of cychlorphine, also known as N-propionitrile chlorphine, in the county's illicit drug supply, officials said.

Like fentanyl and heroin, cychlorphine is an opioid that can slow breathing and cause a fatal overdose. However, its extreme potency makes even small amounts potentially deadly, health officials warned.

The drug is particularly dangerous because it can be mixed into other illicit substances without users knowing, and it cannot be detected by standard fentanyl test strips.

Cychlorphine has been found in powders, counterfeit prescription pills, crystals and liquids.

The drug first appeared in the nation's illicit drug supply in 2024 and has since been detected in 19 states, according to Public Health.

Another cychlorphine-related death was reported in Northern California in April 2026.

In August, the U.S. Drug Enforcement Administration classified cychlorphine as a Schedule I controlled substance, making it illegal to possess or sell. The drug has never been approved for medical use by the U.S. Food and Drug Administration.

Although cychlorphine has been more prevalent in other parts of the country, Los Angeles County health officials said they are monitoring for changes in its presence in the local drug supply.

Public Health officials urged residents to avoid illicit drugs because of the risk of unknowingly consuming cychlorphine.

For people who use drugs, the department recommended several precautions to reduce the risk of a fatal overdose:

• Never use drugs alone. Have someone nearby who can call 911 and administer naloxone if an overdose occurs.
• Start with a small amount and proceed slowly because even a tiny quantity of cychlorphine can stop breathing.
• Avoid mixing opioids with alcohol, sedatives, sleeping medications or other drugs, which can significantly increase the risk of an overdose.
• Carry naloxone, a medication that can reverse opioid overdoses, including those involving cychlorphine.

Naloxone can be administered through a nasal spray or an injection. Both methods are effective, although multiple doses may be necessary to reverse an overdose involving cychlorphine, according to Public Health.

Officials urged anyone witnessing a suspected overdose to immediately call 911 and administer naloxone.

Naloxone nasal spray is available at community health stations, county public health centers, retail pharmacies and through medical providers.

Residents can also have drug samples tested specifically for cychlorphine at no cost through Drug Checking LA.