New Synthetic Opioid 'Cychlorphine' Linked to Over 50 Deaths Nationally, Potency Exceeds Fentanyl

A powerful synthetic opioid, dubbed cychlorphine, has been linked to at least 55 overdose deaths across the United States, according to recent warnings from health officials. This substance is reportedly up to 10 times more potent than fentanyl, a synthetic opioid already responsible for a significant portion of overdose fatalities nationwide.

Tennessee was identified as an early focal point for cychlorphine-related deaths. The state's health department reported in March that more than 30 fatal overdoses had been associated with the drug since October 2025. An April 2026 notice from the White House’s Office of National Drug Control Policy cited at least 41 deaths in Tennessee between July 2025 and February 2026, and a national total of at least 55 deaths.

Fatal overdoses involving cychlorphine have also been reported in Illinois, California, and Oklahoma, according to public health and law enforcement records. Officials describe cychlorphine as particularly dangerous due to its extreme potency, noting that a small amount can cause users to stop breathing.

Nicholas Kardaras, CEO of the New York Center for Living and a clinical professor at Stony Brook Medicine, described cychlorphine as "the new fentanyl on steroids." The Drug Enforcement Administration states that cychlorphine is a novel, unregulated synthetic opioid that activates the same receptors as fentanyl, potentially leading to profound sedation, respiratory depression, and death. The drug is not approved for medical use and has been found in illicit drugs and counterfeit pills.

Kardaras elaborated on the drug's strength, explaining that fentanyl is approximately 50 times more potent than morphine. Cychlorphine, he noted, is reportedly up to 10 times more potent than fentanyl, suggesting a theoretical potency of about 500 times that of morphine. "This new synthetic drug is making fentanyl look like yesterday's candy," he stated.

Cychlorphine can be ingested as a pill, snorted in powder form, or administered intravenously. A significant concern is that it is often mixed into other designer drugs and counterfeit pills, meaning users may consume it unknowingly. "Sometimes by talking about how potent some of these substances are, we increase the allure of them for some addicts, unfortunately," Kardaras said.

While cychlorphine is primarily a street drug, it can also be purchased online. The drug poses a risk to users of all ages, with younger individuals potentially facing greater exposure due to experimentation or the purchase of counterfeit pills. "They’re buying something online … and all of a sudden, without knowing it, they’re ingesting fentanyl or another synthetic opioid," Kardaras warned.

Naloxone, commonly known as Narcan, can reverse the effects of cychlorphine, but multiple or prolonged doses may be necessary. Anecdotal evidence suggests that what previously required one or two doses of naloxone for an overdose might now necessitate five or six. "What used to take one or two doses of Narcan to reverse an overdose may now require five or six doses, based on anecdotal evidence," Kardaras said.

Adding to the danger, standard fentanyl test strips and routine hospital opioid urine screens do not detect cychlorphine. "Most drug tests have very specific chemical structures that they detect in any kind of synthetic or non-synthetic drug, and this new one hasn't quite been baked into the current testing strips," Kardaras noted.

Health officials emphasize that cychlorphine is up to 10 times more potent than fentanyl, is not detectable by current common testing methods, and may require multiple doses of naloxone for reversal, presenting a significant challenge in combating the ongoing opioid crisis. "So it's a triple whammy," Kardaras concluded. "It's a constant battle of keeping up with the latest iterations of new drugs."