This Week’s Focus: Nonfatal Drug-Related Overdoses + Cychlorphine

This week’s NDEWS Weekly Briefing focuses on the overarching view of nonfatal drug-related overdoses across the US via our latest NDEWS Special Report. Additionally, the NDEWS Web Monitoring Team focuses on cychlorphine, which appeared in toxicology reports of 41 deaths in Knox County, Tennessee, from July 2025 to February 2026, as reported in a media release by the Knox County Regional Forensic Center.

The briefing also highlights NDEWS Director Dr. Linda Cottler, who was the recipient of the University of Florida Department of Epidemiology's 2026 College of Public Health and Health Professions’ Dean’s Citation Award, for being the senior author on a paper focusing on NDEWS Rapid Street Reporting. 

As always, we welcome your input.

NDEWS Director Linda Cottler was selected as the recipient of the University of Florida Department of Epidemiology 2026 College of Public Health and Health Professions’ Dean’s Citation Award. This well-earned recognition was for being the senior author of the paper Prevalence and correlates of self-reported new psychoactive substance use among adults in 20 US cities: Results from National Drug Early Warning System surveillance that was published in Drug and Alcohol Dependence. The paper described results from the NDEWS Rapid Street Reporting Study, and was first authored by Dr. Nicole Fitzgerald for her dissertation under the mentorship of Dr. Cottler. Co-Director Dr. Palamar was a co-author.

Nationally, the majority of counties with the highest rates of EMS encounters of nonfatal drug-related overdose rates were seen in the Western and Southern Regions. To view the entire Special Report from the weekly briefing, click here.

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Why are we reporting on this? Cyclorphine is a highly potent synthetic opioid that has recently emerged as a significant topic of discussion within online drug communities. Reddit discussions highlight concerns regarding its extreme potency, which discussants say it has a similar or stronger potency than fentanyl. The substance is being discussed in the context of a shifting illicit drug market where novel synthetic opioids are increasingly available, often being used by individuals with high opioid tolerance who are seeking alternatives to other opioids.

What is Cyclorphine? Cyclorphine is a potent synthetic opioid belonging to the benzimidazole or "nitazene" related structural classes. It is primarily available through online research chemical vendors and is typically found in powder or liquid form. It is often sought out by individuals looking for high-potency alternatives to fentanyl.

Previous Web Monitoring Report:
- September 27, 2024 - Cyclorphine  - Click here for full report.

Public Health Impacts: Reddit discussants report significant adverse effects and safety concerns associated with cyclorphine use, most notably severe respiratory depression and prolonged periods of unconsciousness. Multiple commenters describe experiences of "blacking out" or sleeping for extended durations, sometimes exceeding 24 hours, following use. There are also reports of physical side effects such as swollen lymph nodes and vocal strain after consumption. Discussants frequently mention the necessity of having naloxone on hand due to the substance's extreme potency and the rapid development of high physical tolerance.

How is it Being Discussed? Reddit commenters discuss cyclorphine as a highly effective but dangerous opioid, often noting its superior euphoric effects compared to other synthetic research chemicals like etomethazene or etodezitramide. There is frequent discussion regarding various routes of administration, including smoking on foil, oral consumption, sublingual use, and rectal administration, with the latter often cited as providing the most intense effects. Discussants often compare cyclorphine to fentanyl and heroin. The substance is also discussed in combination with other substances, including stimulants like MD-PiHP and alpha-PVP, as well as kratom derivatives like 7-hydroxymitragynine and various benzodiazepines used to manage withdrawal. Many commenters express a cycle of use where they utilize cyclorphine to manage the perceived "disgusting" withdrawal symptoms of other synthetic opioids, despite acknowledging significant addiction.

Click here to learn more about NDEWS Web Monitoring Reports.

A recently published study in The New England Journal of Medicine, which was co-authored by NDEWS Sentinel Site Director Ellenie Tuazon, highlights state and local collaboration to detect emerging substances of concern in the illicit drug supply and to implement data-guided programmatic responses. The report noted that after months of monitoring, with medetomidine being detected in less than 10% of opioid samples, medetomidine proliferated in the illicit drug supply, with an abrupt and sustained increase to over 20% of collected opioid samples. Read the full study here.

A recently published study in Forensic Science International by Grenier et al. introduced DrugRecon, a RoBERTa based pretrained language model specifically fine-tuned for drug name recognition, to address the challenge of the systematic recognition of emerging new psychoactive substances (NPS). The model was trained and evaluated using an annotated dataset of posts and comments from drug‑related sections on Drugs‑Forum, Dread, and Reddit. The model successfully recognized drug names absent from existing lexicons. By combining automatic recognition with expert validation, 12 names were classified as denoting potential novel NPS. Read the full study here.

A recently published study in the Canadian Journal of Public Health by Tobias et al. examined whether common adulterants identified through drug checking services are associated with increased prevalence of specific adverse events (AEs) reportedly experienced by people who use drugs. Drug samples were analyzed at community sites in British Columbia, and self‑reported AEs following consumption opioid use were statistically examined using methods that accounted for co‑occurring adulterants, expected substance, geographic location, and calendar month. Read the full study here.