A synthetic opioid up to 10 times more potent than fentanyl has been detected in Hamilton County drug samples, prompting warnings from local health and law enforcement officials.

The drug, cychlorphine, was first identified through local testing about a year ago by the Hamilton County Addiction Response Coalition (HC ARC), as first reported by WLWT. In the limited samples where it has appeared, cychlorphine was found mixed with fentanyl, a Hamilton County Public Health spokesperson told the station.

"It's something Hamilton County Addiction Response Coalition picked up on about a year ago with drug testing," Newtown Police Chief Tom Synan told WLWT.

A Hamilton County Public Health spokesperson estimated cychlorphine is four to 10 times as potent as fentanyl. Health and law enforcement officials are urging residents to treat any pill not obtained from a licensed pharmacy as potentially deadly. Counterfeit pills resembling Xanax, Percocet and Adderall may contain cychlorphine, fentanyl or other substances without the user's knowledge, according to the DEA, as Denver7 reported.

Standard fentanyl test strips do not detect cychlorphine, according to substance-abuse resource site Addiction Center. A negative test does not mean a pill or powder is safe.

Dr. Mike Kalfas, an addiction specialist with St. Elizabeth Physicians, called cychlorphine the newest dangerous synthetic opioid to emerge and said it can depress the respiratory system enough to kill. Because of its extreme potency, officials warn that multiple doses of naloxone, commonly sold as Narcan, may be needed to reverse an overdose.

The DEA first spotted cychlorphine in the U.S. illicit drug supply in 2024. As of March 2026, the National Institutes of Health reported at least 24 states had logged overdoses or deaths linked to the drug, including 19 confirmed deaths in East Tennessee and detections in Ohio and Kentucky. In summer 2026, the DEA moved to temporarily classify cychlorphine as a Schedule I controlled substance.

Hamilton County has made progress against the broader opioid crisis. Overdose deaths fell for the fourth straight year in 2025, dropping from 277 in 2024 to 194, the lowest since 2012, according to the HC ARC annual report.

The drug has not been detected on college campuses in Greater Cincinnati, but local officials are discussing prevention efforts, according to WLWT.

As of 2021, Montgomery Police officers carried Narcan, according to the city's addiction resource page. Residents can reach Montgomery Police at 513-985-1600 for information.

Hamilton County Public Health ships Narcan and fentanyl test strips free by mail. Residents can order supplies by calling 513-316-7725.

Anyone who suspects an overdose should administer naloxone, call 911 immediately and stay with the person until paramedics arrive.