Cychlorphine is a synthetic opioid chemical compound which has been sold as a designer drug, which has been linked to hospitalizations and fatal overdoses in the United States, Europe, the United Kingdom and Canada. It is similar in chemical structure to known opioid agonists such as brorphine and spirochlorphine, and is claimed to be an opioid with a similar potency to fentanyl, but no pharmacological data for cychlorphine have been published. It is not a structural analog of morphine, despite the similar name. Instead, it is an orphine. Furthermore, it has been detected as the sole active component in fake pharmaceutical opioid preparations that are supposed to contain hydromorphone or oxycodone, further increasing the risk of accidental overdoses. In July 2026 the Dutch health authority recommended using Naloxone as an immediate treatment
History At least five people died from cychlorphine overdoses in England in 2025. It was first discovered in Canada in September 2025. In Denmark, it has been found within various samples of confiscated drugs and in samples collected during an autopsy of a person who died of a drug overdose in July 2026.
It was added to the German new psychoactive substances act (NpSG) in December 2025.
According to Dr. Darinka Mileusnic-Polchan, a medical examiner working for the Knox and Anderson counties of Tennessee, there have been more than 50 fatal cychlorphine overdoses in the greater Knoxville area between October 2025 and May 2026.
Another death was reported in San Francisco, California, in April 2026. In September 2026 the mother of the overdose fatality went public with the New York Times.https://www.nytimes.com/2026/09/14/us/san-francisco-autopsy-cychlorphine.html
In July 2026, cychlorphine was detected by Welsh authorities in a Traditional Chinese Medicine product sold as Lion's Mane (Hericium erinaceus).
It was proposed for placement on the Schedule I list of the Controlled Substances Act in the US on 1 July 2026,Schedules of Controlled Substances: Temporary Placement of 5,6- Dichloro Brorphine, 5,6-Dichloro Desmethylchlorphine, N-Propionitrile Chlorphine, and Spirochlorphine in Schedule I of the Controlled Substances Act. Department of Justice, Drug Enforcement Administration. 21 CFR Part 1308. Docket No. DEA-1665. 1 July 2026 and has also been recommended for scheduling in individual states such as Kentucky.AN ACT relating to cychlorphine. House Bill 750, Kentucky General Assembly
See also Bezitramide N-Propionitrile brorphine List of orphine opioids
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