Despite only originating in China two years ago, a new opioid potentially more dangerous than fentanyl has been linked to 28 overdose deaths in East Tennessee, according to the Knox County Regional Forensic Center (RFC).
After reporting the presence of N-Propionitrile Chlorphine, or cychlorphine, last week at the East TN Opioid Conference, the county medical examiner’s office shared the information on social media, confirming to the public that the “non-fentanyl related synthetic opioid” is now present in the Volunteer State.
“It originated in China in 2024 and quickly moved to Europe before hitting the United States in the fourth quarter of 2025,” said the forensic center, adding that only nine states have reported the drug’s presence, though many have yet to begin testing.
Last month, Knox County RFC Communications Director Chris Thomas reportedly stated that the drug was appearing at an “exponential rate,” but on Monday stated that Knox County’s advanced testing likely made the medical examiner’s office aware of the situation emerging across the country.
“I hear people say Knox County has a big drug problem but that’s not exactly true – we have the best surveillance,” said Thomas. “A decade ago, drug testing strips were not advanced enough to detect fentanyl and now they are.”
Chief medical examiner Darinka Mileusnic-Polchan said last month that the drug spread to the United States and Europe despite never even being approved for medical use in China.
“This isn’t a drug that has been approved for clinical use, and it’s never been clinically approved to be sold on the market,” said Mileusnic-Polchan, according to Forensic Magazine. “It’s more powerful than fentanyl and naloxone does not completely block the effects of the drug and multiple doses may be needed to prevent an overdose.”
Cychlorphine spreads to Tennessee amid the Trump administration’s efforts to crack down on fentanyl, with President Donald Trump last year classifying the drug a weapon of mass destruction.
The White House has also engaged China over the fentanyl precursors, with the president threatening to raise tariffs over the chemicals that can be converted to the lethal drug and smuggled into the United States.
FBI Director Kash Patel announced last November that his counterparts in China agreed to make the precursors illegal substances.
“The People’s Republic of China has fully designated and listed all 13 precursors utilized to make fentanyl. Furthermore, they have agreed to control seven chemical subsidiaries that are also utilized to produce this lethal drug,” said Patel. “These substances are now banned, and they will no longer be utilized by the Mexican drug trafficking organizations or any other DTOs around the world to make this drug.”
The Trump administration said some of these precursors were smuggled through Venezuela when the U.S. Navy began destroying vessels allegedly filled with drugs last year.
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Tom Pappert is a 2025 recipient of the Dao Prize and the lead reporter for The Tennessee Star. He also reports for the Star News Network. Follow Tom on X. Email tips to [email protected].
There would not be a drug problem if there were not willing customers for this stuff.