New Synthetic Opioid Linked to 41 Deaths in Tennessee

Officials warn of dangerous rise in overdoses from N-Propionitrile Chlorphine, a powerful new drug 10 times more potent than fentanyl.

Apr. 7, 2026 at 6:03pm

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A translucent X-ray photograph showing the ghostly outline of a human heart and lungs, glowing with an ethereal blue-green light against a dark background, conveying the vulnerability of the body to powerful synthetic drugs.An X-ray view of the human body's vital organs reveals the fragility of life in the face of a dangerous new synthetic opioid crisis.Knoxville Today

A new synthetic opioid called N-Propionitrile Chlorphine, also known as cychlorphine, has been linked to at least 41 overdose deaths in East Tennessee since mid-2025. Experts say the drug is approximately 10 times more potent than fentanyl and has been detected in multiple states, often in combination with other substances like fentanyl and methamphetamine.

Why it matters

The emergence of this highly potent synthetic opioid represents a dangerous escalation of the ongoing opioid crisis, as public health officials struggle to keep up with the constantly evolving drug supply. The ability to quickly identify and respond to new threats like cychlorphine is critical to saving lives.

The details

Since July 2025, cychlorphine has been detected in the toxicology of at least 41 overdose deaths across 11 counties in East Tennessee. The drug was first identified less than two years ago in a lab and is believed to have originated in China before spreading to Europe and the United States. Cychlorphine is often found in combination with other substances like fentanyl and methamphetamine, further increasing the risk of fatal overdose.

  • Between July 2025 and February 2026, cychlorphine was linked to 41 overdose deaths in East Tennessee.
  • Since October 2024, cychlorphine has also been detected in toxicology reports in several other states, including California, Illinois, Louisiana, Nevada, New York, Pennsylvania, and Texas.
  • In March 2026, the Oklahoma Bureau of Narcotics reported that cychlorphine had been identified in the state as well.

The players

Center for Forensic Science Research and Education

A research organization that has been tracking the emergence of cychlorphine and its spread across the United States.

Chris Thomas

The chief administrative officer and director of the Knox County Regional Forensic Center, which has been testing for cychlorphine and detecting it in overdose cases.

Dr. Rachel Wirginis

An addiction medicine and family medicine physician at the Oklahoma State University Addiction Recovery Clinic in Tulsa, who has warned that cychlorphine represents a dangerous shift in the opioid crisis.

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What they’re saying

“Cychlorphine represents a dangerous shift in the opioid crisis. We are seeing increasingly powerful synthetic opioids that require rapid recognition and aggressive intervention to prevent fatal outcomes.”

— Dr. Rachel Wirginis, Addiction Medicine and Family Medicine Physician

“We don't know if it's contained to a limited supply or one bad batch, or if it's representative of a longer-term shift in the drug supply. That's what is really concerning.”

— Chris Thomas, Chief Administrative Officer and Director, Knox County Regional Forensic Center

“It has never been more dangerous to take street-level drugs than right now.”

— Chris Thomas, Chief Administrative Officer and Director, Knox County Regional Forensic Center

What’s next

Experts say that the ability to quickly identify and respond to new synthetic opioids like cychlorphine is critical to saving lives. Public health officials are working to expand testing and surveillance capabilities to stay ahead of the evolving drug supply.

The takeaway

The emergence of cychlorphine, a highly potent synthetic opioid 10 times more powerful than fentanyl, represents a dangerous escalation of the ongoing opioid crisis. This underscores the urgent need for enhanced drug monitoring, rapid response, and aggressive intervention to prevent further overdose deaths.