What Is Cychlorphine? New Synthetic Opioid 10 Times Stronger Than Fentanyl Linked to Teen’s Death

A new synthetic opioid called cychlorphine has been linked to the April 7 death of a 16-year-old San Francisco boy, marking the city’s first fatal overdose involving the drug.

Dante Paul Lacourte was found unresponsive in his Lower Nob Hill bedroom by his mother, Christina Lacourte, who gave him two doses of Narcan, but he could not be revived. His autopsy did not identify fentanyl. Instead, it found cychlorphine, a little-known opioid estimated to be about 10 times more potent than fentanyl.

The case has given San Francisco officials a troubling look at how quickly a new drug can enter an already dangerous illicit market. Cychlorphine is difficult to detect with standard fentanyl test strips, can appear in counterfeit pills or other street drugs, and may require repeated doses of naloxone, the medicine sold as Narcan, during an overdose.

What is Cychlorphine?

Cychlorphine, also known as N-propionitrile chlorphine, is a synthetic opioid from a group of extremely powerful compounds known as orphines.

The drug was originally developed in a Belgian research laboratory in the 1960s. Researchers were investigating powerful painkillers that could potentially help patients suffering severe pain from conditions such as bone cancer.

The compounds were never approved for medical use because they were considered too potent and dangerous. But information about how to make them was published in scientific literature and eventually became available online.

That has created a new problem for drug enforcement and public health agencies. Unlike plant-based drugs that require crops or large production networks, highly potent synthetic opioids can potentially be produced in relatively small, unregulated laboratories.

Stanford psychiatry professor Keith Humphreys, a former senior drug policy adviser in the Obama administration, said the technology has lowered the barrier to producing powerful opioids.

“You don’t need to be a big pharma company,” Humphreys said, explaining that such drugs can be produced without the agricultural resources required for substances such as heroin, cocaine or marijuana.

Why is Cychlorphine so dangerous?

The biggest concern is its extreme potency.

Experts cited by the New York Times gave the estimate that cychlorphine is about 10 times more potent than fentanyl, and that even very small quantities can potentially produce powerful opioid effects.

Its presence is also difficult to identify because standard fentanyl test strips do not detect cychlorphine.

The drug can also appear alongside other substances. In Dante’s case, investigators found evidence of another synthetic opioid, N-desethyl isotonitazene, as well as ethyl bromazolam, an unapproved benzodiazepine.

The combination makes the illicit drug supply particularly unpredictable. Someone buying what appears to be a familiar prescription pill may have no reliable way of knowing which substances are actually inside it.

Bob Beris, special agent in charge of the Drug Enforcement Administration’s San Francisco Field Division, told ABC that cychlorphine does not necessarily remain limited to counterfeit pills.

“It can be mixed into a pill. It can be sold as a powder. It can be mixed in with cocaine. It can be sold as cocaine,” Beris said. “Again, just because we haven’t seen some of these examples yet doesn’t mean it’s not out there.”

How did it reach San Francisco?

San Francisco health officials first warned about the drug in April 2026, after identifying it in connection with an overdose.

Dante died on April 7. Seventeen days later, city health officials held a news conference warning residents about a synthetic opioid that was more potent than fentanyl.

The drug’s presence subsequently became a law enforcement concern. San Francisco police investigated Dante’s death by examining evidence recovered from his bedroom and tracing communications on his cellphone.

According to police, investigators identified people Dante had contacted about buying pills. Undercover officers later purchased drugs from suspected sellers, helping investigators obtain warrants.

On Sept. 8, police arrested Nicholas Wallace, 46, in the Tenderloin and Sharonee Hyson, 44, who was on parole. The following day, officers arrested Leander Pitts, 46, and Starr Lamare, 39, in Bayview-Hunters Point.

Police recovered more than 20,000 pills during the investigation, including suspected counterfeit Xanax and oxycodone, along with fentanyl and other drugs. Firearms and cash were also seized.

The four suspects face felony narcotics and firearms charges. Prosecutors said additional charges could follow if investigators establish who supplied the pill that killed Dante.

Why officials are worried about the next victim

The investigation has also suggested that Dante’s death may not have been an isolated incident.

Pills recovered during earlier, unrelated arrests reportedly tested positive for cychlorphine, indicating that the drug may already have been circulating through multiple sources in San Francisco.

That makes early detection especially important. San Francisco had previously used wastewater testing to monitor substances appearing in the city’s drug supply, but federal funding for the program ended in 2024. The city resumed testing in July and plans to publicly release information about newly detected substances this fall.

Humphreys said wastewater monitoring could help authorities identify dangerous drugs before they are discovered through fatal overdoses. “The worst possible way to find out a new drug is in the city is by an autopsy,” he said.

For Dante’s mother, that autopsy became the first clear warning that the drug supply around her son had changed. She had kept Narcan at home because she feared a fentanyl overdose, but the two doses were not enough to save him.

The case now shows why fentanyl is no longer the only opioid threat officials are watching. As increasingly powerful synthetic compounds enter the illicit market, identifying what is actually inside a counterfeit pill can become as difficult as treating the overdose itself.