LOS ANGELES, CA – Los Angeles County has recorded its first fatal overdose tied to cychlorphine, a synthetic opioid that Public Health officials say is more potent than fentanyl, after the County of Los Angeles Medical Examiner identified the drug as a cause of a death that occurred in February, according to the Los Angeles County Department of Public Health.
The department issued the warning Oct. 15 in a news release titled “First Fatal Overdose Tied to Potent Opioid Cychlorphine Reported in Los Angeles County.” The release says the Medical Examiner recently identified the drug, which is also known as N-propionitrile chlorphine, as a cause of a death that occurred in February 2026.
Public Health described the fatality as the first confirmation of cychlorphine in the local illicit drug supply. The release does not identify the person who died, give an age or describe the circumstances of the death.
According to the department, cychlorphine is more potent than fentanyl and can cause respiratory depression and death. Public Health said even a small amount can cause a person to stop breathing. Officials said laboratory testing suggests the drug is roughly 10 times as strong as fentanyl.
The release also sets out steps people can take to lower the risk of an overdose, from carrying naloxone to using free drug checking, along with treatment and poison-control resources.
Drug found in several forms since 2024
Cychlorphine has been known in the illicit drug supply in the United States only since 2024, Public Health said, and it has been detected in 19 states.
The U.S. Drug Enforcement Administration describes N-propionitrile chlorphine in a drug fact sheet as a synthetic opioid that appeared on the illicit market in 2024. The sheet says the substance is not approved for medical use in the United States and that DEA toxicology has detected it in 44 fatal overdose cases since 2025.
Public Health said the drug has been found in powders, counterfeit tablets, rocks or crystals, and liquids. The counterfeit tablets are made to look like prescription medication, the department said.
According to initial reports, California has had at least one other confirmed cychlorphine death, a 16-year-old in San Francisco in April.
Fentanyl test strips cannot detect the drug
Public Health said cychlorphine is “currently undetectable by fentanyl testing strips” and is being mixed into the illicit drug supply without people knowing.
Because the strips cannot pick up the drug, a negative fentanyl test result does not rule out cychlorphine, the department said. It pointed residents to a separate free drug checking service, described below.
County overdose deaths fell in 2025
The warning follows a decline in overdose deaths countywide. Public Health reported in a June 25 news release that there were 2,298 accidental drug overdose and poisoning deaths in Los Angeles County in 2025, down 6% from 2024 and below the all-time high of 3,220 deaths in 2022.
Fentanyl-related overdose deaths fell about 10% in 2025 to 1,135, or 49% of all overdose deaths, according to the department’s Substance Abuse Prevention and Control reports.
Public Health Director Barbara Ferrer said in that release, “Three consecutive years of fewer overdose deaths in LA County is proof that sustained investments in prevention, harm reduction, treatment, and recovery services saves lives.”
The June figures cover calendar year 2025, so they do not include the February 2026 death.
Public Health lists steps to reduce risk
Public Health advised residents not to use drugs alone. It also urged people to start with very small amounts and not to mix drugs.
The department said residents should carry naloxone, the medication used to reverse an opioid overdose. Naloxone can reverse a cychlorphine overdose, though multiple doses may be needed, according to Public Health.
The medication can be given through the nose or as an intramuscular injection, the department said.
The county’s harm reduction page covers overdose prevention for residents, including naloxone and drug checking.
Free drug checking and helplines available
Public Health said residents can get free drug checking through Drug Checking LA at drugcheckingla.com, with results in about 15 to 20 minutes.
The release lists Poison Control at 1-800-222-1222. People seeking treatment or recovery services can call the county’s Substance Abuse Service Helpline at 800-854-7771 or use SUDHelpLA.org.
Temporary Schedule I order runs two years
In August 2026, the DEA classified cychlorphine as a Schedule I drug, making it illegal to possess or sell, according to the release.
The agency’s Federal Register notice, published Aug. 27, 2026, temporarily placed N-propionitrile chlorphine and three related substances in Schedule I, effective that day. The other substances are 5,6-dichloro brorphine, 5,6-dichloro desmethylchlorphine and spirochlorphine.
The temporary order lasts two years and can be extended while permanent scheduling is considered. The DEA had published a notice of intent on July 1, 2026.
The release reports one confirmed Los Angeles County death tied to cychlorphine and announces no additional local cases.
