Drug Said to Be 10 Times More Potent Than Fentanyl Sparks Warning Among Colorado Students

A warning spreading among students at Colorado State University has put an unfamiliar name in front of people who may already know the danger posed by fentanyl: cychlorphine.

The synthetic opioid has not been detected by the Drug Enforcement Administration in Colorado or the other states covered by its Rocky Mountain Division, the agency told FOX31. The division said the closest reported cases it was aware of were in Texas and Oklahoma.

That has not stopped concern from reaching Colorado. Students told the station they were sharing warnings because cychlorphine can turn up in drugs without the person taking them knowing it is there.

The national evidence behind those warnings has been building for months. Cychlorphine, also called N-propionitrile chlorphine, is an emerging synthetic opioid from a group known as orphine analogues. Forensic researchers began seeing a sharp increase in detections in fatal overdose cases in late 2025 and early 2026.

The often-repeated claim that cychlorphine is roughly 10 times more potent than fentanyl comes from laboratory pharmacology rather than studies of human dosing. The Center for Forensic Science Research and Education reported in January that in-vitro data suggested that level of potency while warning that detections of the drug were rising quickly.

What Turned Up

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CFSRE said it had identified cychlorphine in 25 blood specimens from fatal overdoses, with most submitted during late 2025 and early 2026. It was the only opioid detected in 11 of those 25 cases. Another laboratory had tentatively identified it in more than 100 toxicology cases.

Federal data released later showed a wider footprint. An August Federal Register notice said cychlorphine had been confirmed in 225 law-enforcement encounters across 19 U.S. jurisdictions and had been associated with at least 55 fatalities in the United States as of early 2026.

The DEA had already issued a nationwide public safety advisory in May about illicit fentanyl being mixed with cychlorphine, nitazenes, xylazine, medetomidine and other emerging substances. The agency described cychlorphine and nitazenes as potent synthetic opioids and warned that some overdoses involving them may require repeated doses of naloxone.

Federal officials took another step in August, temporarily placing cychlorphine and three related synthetic opioids into Schedule I under the Controlled Substances Act. Temporary scheduling can be used when the DEA determines that controlling a substance is necessary to avoid an imminent hazard to public safety.

A Fatal Trail

The drug has already surfaced in criminal investigations.

In Oklahoma, two men pleaded guilty in federal court to distributing cychlorphine that ultimately resulted in another person’s death. Court records cited by the DEA showed pills containing the drug changed hands in December 2025 before being resold to the person who died.

A separate investigation in San Francisco began after a 16-year-old was found dead in April. The San Francisco Police Department said the medical examiner determined that the teenager died from a combination of drugs that included cychlorphine.

Police later arrested four people and seized more than 20,000 suspected counterfeit pills during searches in September. The pills included substances represented as Xanax, oxycodone and other drugs. Police said testing of pills from earlier investigations had detected cychlorphine, while additional testing was underway on pills seized in the September operation.

The case illustrates one of the concerns surrounding emerging synthetic opioids: what a pill looks like does not establish what is actually inside it.

Harder To Spot

That uncertainty also extends to testing.

Cychlorphine is not detected by fentanyl test strips simply because those strips are designed to identify fentanyl, not every opioid that may be present in an illicit drug supply. Specialized laboratory testing may be needed to identify newer synthetic substances.

Colorado health officials told FOX31 that the state had not recorded an overdose death specifically involving cychlorphine. They also cautioned that the drug is not part of standard post-mortem toxicology panels and could be missed unless a coroner specifically requests testing for it.

That distinction matters when interpreting the available numbers. A lack of identified cases does not necessarily establish that the substance has never been present.

The Colorado Department of Public Health and Environment said naloxone remains appropriate for overdoses involving synthetic opioids such as cychlorphine. Because cychlorphine acts on opioid receptors, naloxone can reverse its opioid effects, although repeated doses and emergency medical care may be necessary in a severe overdose.

For now, the DEA’s Rocky Mountain Division says it has not encountered cychlorphine within Colorado, Montana, Utah or Wyoming. The warning circulating among CSU students is arriving before a confirmed local detection — not after one.