This Week’s Focus: Monitoring Emerging New Psychoactive Substances

The National Drug Early Warning System (NDEWS) is committed to identifying new and emerging threats related to substances before they lead to widespread harm. One of the ways we achieve this is through real-time online web monitoring, which allows our network to detect early signals of emerging substances in digital spaces where drug-related conversations occur.

In our latest Web Monitoring Report, the NDEWS team observed an increase in Reddit discussions about SR-17018, a brorphine analog. The trend was detected through algorithmic monitoring of drug-oriented subreddits, combined with machine learning models that identify anomalous keyword activity. Historically, these online signals have proven predictive of later appearances in toxicology data and other real-world indicators. This substance was reported to the United Nations Office on Drugs and Crime in 2024.

This week’s Briefing includes the full Web Monitoring Report along with curated resources and studies on brorphine and its analogs to further our understanding. Through analyzing these insights, NDEWS continues its mission to provide timely, actionable intelligence to public health and safety partners.

As always, please reach out with any information you might have on this substance.

Why are we reporting on this?
SR-17018 has emerged as a topic of discussion on Reddit with commentors sharing detailed protocols for ingesting this drug as a substitute to discontinue various opioids. Protocols include extensive peer-developed guides, automated taper calculators, and compilation documents. They have been widely shared.

What is SR-17018?
SR-17018 is a biased G-protein μ-opioid receptor agonist that selectively activates G-protein signaling pathways over β-arrestin 2 recruitment. According to reports made by Reddit commenters, this allows for the management of opioid withdrawal symptoms while simultaneously reducing tolerance to opioids. Discussants describe it as producing minimal euphoria or analgesic effects, distinguishing it from traditional opioid agonists.

Public Health Impacts:
Reddit commentors report using SR-17018 to discontinue a wide range of opioids such as fentanyl, heroin, methadone, buprenorphine, prescription opioids, synthetic opioids (zenes), and kratom. Discussants describe highly variable dosing requirements across individuals. A critical safety concern raised across multiple discussions is the risk of fatal overdose if individuals return to opioid use after their tolerance has been reduced by SR-17018. At least one fatality has been referenced in this context. Commenters acknowledge complete absence of established safety data and express uncertainty about potential long-term health effects. The purported delayed onset of effects (1-2 hours) creates challenges in managing acute withdrawal symptoms and may lead to inappropriate redosing.

How is it Being Discussed?
Reddit discussants have created comprehensive documentation for generating personalized taper schedules. Discussants share specific protocols involving calibration phases, maintenance periods, and tapering schedules, with detailed logging recommendations. These peer-developed resources are widely referenced and shared across multiple subreddit communities. Reddit commentors frequently discuss SR-17018 as an alternative to traditional medication-assisted treatment options like methadone and buprenorphine, with some expressing frustration about limited access to addiction treatment. Some discussants report combining SR-17018 with benzodiazepines, gabapentin, clonidine, and antihistamines to manage residual symptoms. Additionally, some commenters report that ingesting ketamine concurrently for psychological support during withdrawal.

The compound is primarily discussed in the context of its reported ability to reduce cravings, with multiple Reddit commentors noting diminished desire to use opioids even when substances are readily available. However, discussants also acknowledge that SR-17018 addresses primarily physical withdrawal rather than psychological aspects of addiction.

Drug Terms:
SR-17018, SR17018

The United Nations Office on Drugs and Crime Early Warning Advisory Summary Dashboard gives an in depth look into the data collected on new psychoactive substances (NPS) dating back to 2008. The dashboard is able to filter data on NPS by year, geographical location and effect group. Access the public version of the dashboard here.

A recently published United Nations Office on Drugs and Crime Early Warning Advisory on New Psychoactive Substances (NPS) announced that several brorphine analogs, including SR-17018, were reported to the UNODC for the first time in 2024. The advisory noted that brorphine analogs have been found in powder, rock-like solid, and plant material forms. Additionally, it was noted that immediate medical care is critical as naloxone may not be fully effective or may require repeated dosing for some brorphine analogs. Read the advisory here.

A recently published study in the International Journal of Molecular Sciences by Lenzi et al. investigated the genotoxicity of brorphine and its analogs (orphine, fluorphine, chlorphine, and iodorphine) using human lymphoblastoid TK6 cells. The results indicated a statistically significant increase in micronuclei for fluorphine, chlorphine, and iodorphine, but not for brorphine and orphine. The results suggest that fluorphine, chlorphine, and iodorphine compounds can induce chromosomal damage, while brorphine and orphine do not exhibit mutagenic effects. Read the study here.

A recently published NPS: Snapshot by Cayman Chemical spotlighted orphines; a new wave of synthetic opioids that are distinct from fentanyl and its analogs. Orphines, also known as piperidinylbenzimidazolones, are novel synthetic opioids that were initially developed for their anesthetic and antitussive properties. SR-17018 (5,6-dichloro Desmethylchlorphine) contains the chlorphine scaffold, but lacks the methyl group at the benzyl location and has two chlorine substituents at the 5- and 6-positions on the benzimidazolone. Read the report here.

A recently published study in CNS Drugs by Breault et al. reviewed the development and challenges of opioid analgesics with a focus on SR-17018. This µ-opioid receptor (MOP) agonist showed a strong G-protein bias with a therapeutic window nearly 30 times the ED50 for analgesia, unlike morphine and fentanyl. The study found that SR-17018 did not induce respiratory depression at analgesic doses and did not cause tolerance. Read the full study here.

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The NDEWS Weekly Briefing curates emerging data and findings from across the Early Warning Network, which includes three core components: our Scientific Advisory Group (SAG), comprised of national experts and federal partners; our Sentinel Site Directors (SSDs), who lead local surveillance in key geographic regions; and our Community-Based Health Experts, who provide on-the-ground insights from populations most impacted by drug trends. Together, these contributors generate timely, multidisciplinary and impactful information, ranging from peer-reviewed research findings to local surveillance data. These contributions inform public health and research communities.

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If you miss or want to learn more about NDEWS Original Content, you can find our archived content on the NDEWS website:

     • NDEWS Hotspot Alerts using substance-related EMS data
     • NDEWS Rapid Street Reporting (RSR) survey data reports
     • NDEWS Web Monitoring Team Reddit Alerts
     • NDEWS Sentinel Site Reports
     • Previous issues of the NDEWS Weekly Briefings

The Weekly Briefing is a newsletter published each week by the National Drug Early Warning System (NDEWS) Coordinating Center, which is funded by the National Institute on Drug Abuse (U01DA051126) to the University of Florida (MPI: Cottler (contact), Co-Is: Goldberger, Nixon, Striley), NYU Langone Health (MPI: Palamar), and Florida Atlantic University (Co-I: Barenholtz). Any item may be reproduced provided the source is acknowledged.