Health officials are warning Hamilton County residents about cychlorphine, a synthetic opioid up to 10 times more potent than fentanyl found in local drug samples.

Symmes Township and the Hamilton County portion of Loveland fall under the county warning. Milford, mostly in Clermont County, borders it. No specific cases in those communities have been publicly reported, but the county-level detections put area residents on notice.

The Hamilton County Addiction Response Coalition first identified cychlorphine about a year ago through drug testing, Newtown Police Chief Tom Synan told WLWT in a report published Monday, Sept. 28. In the limited samples where it appeared, cychlorphine was found mixed with fentanyl, a Hamilton County Public Health spokesperson told the station.

"It's the newest monster to come on the scene," said Dr. Mike Kalfas, an addiction specialist with St. Elizabeth Physicians.

Cychlorphine belongs to a new class of synthetic opioids called orphines. It was first developed as a research compound in the 1960s, according to Denver7. The Drug Enforcement Administration (DEA) placed it on a temporary Schedule I of the Controlled Substances Act on Aug. 27, according to MedicalDaily.

The Office of National Drug Control Policy linked cychlorphine to 55 deaths nationwide between 2025 and 2026. Ohio is among the states with the highest prevalence, USA Today reported.

What residents should know

Standard fentanyl test strips do not detect cychlorphine. A negative result does not mean a pill is safe.

Health officials told WLWT that any pill not obtained from a licensed pharmacy should be treated as potentially deadly. Counterfeit pills can contain cychlorphine, fentanyl or other powerful substances without the buyer's knowledge.

Naloxone, sold under the brand name Narcan, can reverse an overdose from cychlorphine. Because of the drug's extreme potency, multiple doses may be needed. Anyone who suspects an overdose should administer naloxone, call 911 and stay with the person until paramedics arrive.

Ohio residents can get free naloxone by mail through HarmReductionOhio or through the state's Project DAWN program, which operates more than 180 distribution sites coordinated by the Ohio Department of Health, according to GoodRx. Hamilton County and the University of Cincinnati expanded access to free Narcan at 24 identified overdose hotspots in the Cincinnati area as of Sept. 16, according to WCPO.

The warning gained national urgency after two University of Mississippi students were found dead Sept. 21. Investigators found packaged kratom in their rooms, though the presence of cychlorphine has not been confirmed by law enforcement, according to The Daily Mississippian.

The Kentucky Office of Homeland Security issued its own cychlorphine warning in February 2026. Synan, who helped form the Hamilton County Addiction Response Coalition after witnessing a family lose a mother and three sons to overdoses, said the coalition has been tracking the drug through testing for about a year.

Hamilton County Public Health can be reached at (513) 946-7800.