It’s an unfamiliar name that comes up in alerts from state medical examiners, local law enforcement and college campuses: cychlorphine.

The synthetic opioid has been linked to at least 122 deaths in the US since July 2025, and in April, the Office of National Drug Control Policy identified it as an “emerging drug threat.”In August, the US Drug Enforcement Administration designated cychlorphine as temporary Schedule I drug, making it illegal in the United States.

But experts say they don’t expect it to become as widespread or dangerous a problem as many other illicit opioids. Here’s what to know about cychlorphine.

Cychlorphine is from a relatively new class of opioids called orphines that haven’t been used for medicinal purposes in the past, according to Dr. Nabarun Dasgupta, a street drug scientist at the University of North Carolina at Chapel Hill. Cychlorphine cases are “sporadic” in the United States, he said, appearing significantly less often than fentanyl samples.

UNC researchers first detected the drug in the United States in August 2024, Dasgupta said. He noted that his colleagues in Europe had been seeing orphines in 2019 and had been watching for the group of drugs to emerge in the US since then.

Cychlorphine showing up in the United States is also a consequence of countries around the world making fentanyl analogs illegal, he said. This has pushed illicit markets to create drugs that are not fentanyl-related but have the same effects on users. “It’s not surprising that it’s showed up,” Dasgupta said.

Cychlorphine has been seen in about 25 states across the country, according to Dr. Alex Krotulski, director of toxicology and chemistry at the Center for Forensic Science Research and Education.

In the Midwest, including Illinois and Tennessee, the drug has been seen in a powdered form, often mixed alongside fentanyl and heroin. In the South, including Texas, Louisiana and Alabama, cychlorphine has appeared in a pill form.

Laboratory-based models show that cychlorphine is more potent than fentanyl, which correlates to what researchers can see in humans, Krotulski said. Due to the potency of the drug, it takes only a small amount to get a bigger effect.

Dr. Shravani Durbhakula, director of comprehensive pain service at Vanderbilt University, said that because cychlorphine is an opioid, it works on opioid receptors to cause respiratory depression, which is when people stop breathing or their breathing becomes slowed. Cychlorphine can also cause sedation and euphoria, decreased consciousness and unresponsiveness. Symptoms can be reversed with naloxone, the opioid overdose reversal drug also known as Narcan.

In cases Durbhakula has seen, cychlorphine is often combined with other substances, even in counterfeits of Xanax and OxyContin, making the effects more powerful and dangerous.

“It’s also been found by itself, so it doesn’t mean that it’s always mixed,” Durbhakula said. “But obviously, if you combine it with other things, it gets even more deadly.”

Fentanyl test strips do not detect cychlorphine because they’re different drugs, according to Dr. David Liss, an associate professor of emergency medicine at Washington University.

The drug is not on typical tests in hospitals, he said, so they may have to order specialized tests to detect it. “I don’t believe that that there’s any kind of way to test for this on an individual scale,” Liss said.

Liss said he also thinks there’s an undercount of cases related to the new compounds, as hospitals cannot identify orphine drugs and it’s not clear whether they’re routinely tested in other labs.

Krotulski thinks cychlorphine will “fall off here pretty quickly” because it has been scheduled by the DEA and in China, which is the source for many novel opioids. He predicts that the number of cases will decline, appearing only as one-offs in the future.

Still, he said, cychlorphine is just one of at least 100 different opioids that he’s seen appear in the last decade, and he is expecting for new opioids to emerge down the road.

“For example, we’re not going to be talking about cyclorphine next October,” Krotulski said. “We’re going to be talking about the new and latest opioids, and there may be three or four until that time.”