Highly potent synthetic opioids: new EUDA threat assessment report outlines risks and response options for Europe

Today, on International Day Against Drug Abuse and Illicit Trafficking, the European Union Drugs Agency (EUDA) publishes a new threat assessment report examining how highly potent synthetic opioids (HPSOs) could affect Europe over the next two years and what this could mean for public health and security preparedness.

The report - Assessment of the threat posed by highly potent synthetic opioids in Europe - focuses on two scenarios: the rapid emergence of new HPSOs, with exposure largely confined to illicit opioid markets, and their rapid emergence in products sold as non-opioids, potentially extending risks beyond existing opioid-using populations. The scenarios are not predictions of what will happen, but preparedness tools to examine how risks could evolve and what this would mean for response. The assessment, a product of the EUDA Threat Assessment System (ETAS) (¹), draws on structured expert input, laboratory findings, clinical and forensic information and drug-checking and law-enforcement seizure data across Europe.

While heroin remains Europe's most commonly used illicit opioid and continues to account for a large share of opioid-related harms, the report expresses 'high concern' over HPSOs due to their extreme potency and the speed with which harms can emerge in local markets. Even very small quantities of HPSOs can cause severe poisoning, and the appearance of these substances in fake medicines, or in products sold as other drugs, can expose people who did not intend to use opioids to greater health risks. International experience, particularly from North America, demonstrates how patterns of harm associated with HPSOs can change rapidly, underscoring the importance of maintaining preparedness and vigilance in Europe.

The assessment notes that Europe's current situation remains heterogeneous, with marked differences between countries and drug market settings, and with signals involving different substance groups, including nitazenes, fentanyl analogues and, more recently, orphine opioids. While the strongest HPSO signals continue to come from the Baltic region, episodic detections and misrepresented products have also been reported elsewhere in Europe, including in northern, western and central European countries. As highlighted in the European Drug Report 2026, attention has also focused recently on two orphines, cychlorphine and spirochlorphine, which have been linked to seizures, non-fatal poisonings and deaths in parts of Europe and are now being formally risk assessed in the EU.

The analysis identifies a number of preparedness priorities for EU Member States. These include improving the detection and monitoring of HPSOs, strengthening coordination and information-sharing between authorities, and ensuring that overdose prevention and response measures can be rapidly expanded when needed. It highlights the importance of wider access to the overdose-reversal drug naloxone, opioid agonist treatment (OAT) and practical overdose prevention information.

The report concludes that there is a 'plausible risk' of the further emergence of HPSOs in Europe. It stresses the need for preparedness, early warning and cooperation, while encouraging Member States to remain alert to both nitazenes and newer opioid groups, such as orphines.

(¹) ETAS supports European countries in assessing and responding to emerging drug-related threats. This EUDA service is designed to help Member States identify, assess and respond to serious health and security threats linked to drug markets, illicit substances and patterns of use that may impact the EU. Watch our ETAS explainer video