A 16-year-old boy’s death in San Francisco has brought renewed attention to cychlorphine, a relatively new synthetic opioid that public health and law enforcement officials say is significantly more potent than fentanyl.
Dante Paul Lacourte, a teenager, died April 7 of an apparent drug overdose in his home in San Francisco. His autopsy also found cychlorphine to be in his system and the case is the city’s first known fatal overdose involving the drug.
The case has caused concern because cychlorphine can show up in counterfeit pills and could not be detected using the commonly used fentanyl test strips. And the widespread use of fentanyl in illicit drug supplies could present additional problems for overdose prevention and treatment, authorities have said.
What is Cychlorphine?
Cychlorphine (N-propionitrile chlorphine) is a synthetic opioid in the orphine analogue class. The U.N. Office on Drugs and Crime (United Nations Office on Drugs and Crime) has called it a new synthetic opioid with a potency more than fentanyl.
In the U.S., cychlorphine is up to 10 times more powerful than fentanyl, federal public health officials have said. The Tennessee Department of Health warned in March after linking the drug to more than 30 fatal overdoses in the state since October 2025.
The SFPD last week made four arrests and seized more than 20,000 counterfeit pills, fentanyl, and firearms after diligently investigating the death of a 16-year-old San Franciscan who died of an overdose from counterfeit pills. The Medical Examiner found cychlorphine, a synthetic… pic.twitter.com/qBaGolJz89
— Daniel Lurie 丹尼爾·羅偉 (@DanielLurie) September 15, 2026
The drug has been detected in North America more frequently than ever since 2024. Cychlorphine has been reported in 10 countries and in drug seizures and post-mortem investigations of fatal overdoses, according to the UNODC. Many of the cases also involved other substances like fentanyl, other synthetic opioids and benzodiazepines.
Its presence in the illegal drug supply is especially concerning because people who are using a counterfeit pill or the other illicit substance might not realise that cychlorphine is present.
Why Cychlorphine is so hard to detect?
One of the biggest concerns with cychlorphine is detection. Standard fentanyl test strips are not meant to identify the drug; a negative fentanyl test does not necessarily mean that a substance is free of other highly potent synthetic opioids.
The drug has also been detected in counterfeit pharmaceutical tablets. The UNODC reported detections of cychlorphine in falsified versions of medicines such as Xanax, Percocet, Dilaudid and OxyContin.
San Francisco police said counterfeit pills that resembled common prescription drugs were among the drugs used in the teen’s death. Four people have since been arrested, and counterfeit pills, firearms, and other drugs have been seized, and investigators are still trying to determine if suspects were connected to the teen’s overdose.
Cychlorphine is associated with fatal overdoses.
The San Francisco case is part of a wider pattern of cychlorphine detection in fatal overdose investigations.
The UNODC reported 78 cychlorphine-related post-mortem cases in the United States and the United Kingdom in its early warning update in May 2026. Many of these cases involved multiple substances, making the exact involvement of cychlorphine in individual deaths hard to know.
In Tennessee, health officials reported more than 30 fatal overdoses from cychlorphine between October 2025 and March 2026. In Cook County, Illinois, seven deaths were linked to the drug in the first half of 2026, according to the county medical examiner’s office.
Health officials say naloxone (commonly known as Narcan) can reverse an opioid overdose involving cychlorphine. But many times, because of its potency, multiple doses are needed, Tennessee health officials and other experts say. Emergency medical assistance in the event of an opioid overdose is needed immediately.
The development of cychlorphine has also been another challenge in the ongoing synthetic opioid crisis. When new drugs get into the illicit drug market, public health agencies and forensic laboratories have to find them quickly and determine their effects.
For families and communities, the death of the San Francisco teenager has made the risks of counterfeit pills and illegal drugs more apparent. Now officials monitor cychlorphine’s spread and law enforcement authorities are investigating the networks that distributed it.
