A dangerous cychlorphine opioid is sweeping across Tennessee, and public health officials are raising the alarm. Knox County authorities have now tied it to 16 overdose deaths. The drug spreads fast, combines lethally with other substances, and resists standard reversal treatments.

Formally named N-Propionitrile Chlorphine, this new synthetic opioid is up to ten times more potent than fentanyl. Manufacturers never sought clinical approval for it. No regulatory body has ever authorised it for sale. Yet it is already killing people across multiple Tennessee counties.

How the Cychlorphine Opioid Arrived in Tennessee

The Centre for Forensic Science Research and Education traces cychlorphine’s origins to China in 2024. By mid-2025, it had spread to Europe and Canada before reaching the United States.

Tennessee first encountered the drug in late November 2025. Knox County Regional Forensic Centre identified it following a Roane County overdose death. Later, officials traced an earlier Knox County case back to October of that year. Between late October and December 2025, nine people died. By mid-January 2026, seven more fatalities had emerged, bringing the confirmed total to 16.

The drug did not stay in Knox County. It spread to Roane, McMinn, Campbell, Union, Anderson, Claiborne and Sevier counties. Officials at Nashville-based AEGIS Sciences Corporation have since confirmed that the new synthetic opioid Tennessee communities are battling has now reached Middle Tennessee.

On 16 January, the UK Harm Reduction Hub, a University of Kentucky initiative that monitors the state’s street drug supply, detected cychlorphine in a syringe from Fayette County, Kentucky. Fayette County sits less than three hours from Knoxville. The Hub confirmed that “cychlorphine has now been associated with an increase in fatal overdoses.”

Why This New Synthetic Opioid Tennessee Is Seeing Is So Dangerous

Dr Darinka Mileusnic-Polchan, chief medical examiner at Knox County Regional Forensic Centre, laid out the risks clearly. “This is not a drug that anyone has approved for clinical use,” she said. “It is more powerful than fentanyl and naloxone, or Narcan, does not completely block its effects. Multiple doses may be needed to prevent an overdose.”

That last point matters enormously. Naloxone has served as a frontline overdose reversal tool for years. But this cychlorphine opioid can overwhelm a single dose. Emergency responders and people carrying naloxone now need to administer several doses if they suspect an overdose.

None of the 16 deaths involved cychlorphine alone. Chris Thomas, chief administrative officer and director of Knox County Regional Forensic Centre, confirmed that every fatality occurred alongside other substances, mostly methamphetamine and fentanyl.

Dr Josh Schrecker, Clinical Affairs Senior Director at AEGIS Sciences Corporation, explained the core danger. “When we see it, it is often in a pretty complex mixture of drugs, and that is really where the risk is,” he said. “People who buy something on the street rarely know what is actually in it or how much.”

The Broader Threat: Where Does It Come From?

This cychlorphine opioid did not originate domestically. Dr Schrecker pointed to overseas manufacturing as the likely source. “They are probably being made in parts of the world where these substances are not illegal,” he said. “Then they get imported into the United States.”

Thomas put it directly. “It is showing up at an exponential rate,” he said. “We do not know if this is a single batch or the new future.”

The Tennessee Bureau of Investigation confirmed its Drug Investigation Division is now working with local law enforcement to track down suppliers.

Anyone who witnesses a suspected overdose should seek emergency help immediately and administer naloxone if available. Given how this drug behaves, multiple doses may be necessary.

Source: dbrecoveryresources