The State of the Unregulated Drug Supply in Ontario

By: Prof. Michael A. Beazely, Associate Professor at the University of Waterloo's School of Pharmacy and Gateway Centre of Excellence in Rural Health's Chair of Rural Substance Use 

Professor Michael Beazely

A Brief History 

The past decade has seen frequent and rapid changes to the unregulated (i.e. illegal) opioid supply. Beginning in the mid-2010s, fentanyl began to replace heroin in the unregulated drug supply. Initially viewed as a contaminant of heroin, fentanyl, a much more potent opioid, soon dominated. As we moved into the 2020s, the unregulated drug supply became even more complex, including not only fentanyl itself, but closely related fentanyl analogues, non-fentanyl opioids, various benzodiazepines, and veterinary tranquilizers. 

Drug Checking 

An effective harm reduction tool for people who use drugs are fentanyl test strips that can detect the presence of fentanyl and its analogues. However increased complexity of the drug supply motivated people who use drugs, service providers, policy makers, and researchers to develop drug-checking services that could accurately identify samples containing multiple drugs. Improved technology and reduced costs resulted in the placement of several analytical devices and drug-checking services, often located within existing supervised consumption sites (SCS). 

In 2025, new provincial regulations in Ontario resulted in the closure of numerous SCSs. The biggest impact of SCS closures is on the people who use the service. However, in many cases, these closures also resulted in closures of the drug-checking service as well.

Unfortunately, the homeless and addiction recovery treatment (HART) hubs, emphasizing treatment over harm reduction, will not be offering drug checking services. Again, the biggest impact is on people who use drugs (and who may decide to alter their drug use based on drug-checking results), but these closures also reduce our ability to understand the unregulated drug supply in real time. In some jurisdictions, such as Kitchener-Waterloo, the drug checking service has moved to other locations including via their mobile community health van. 

Certain drug-checking services, such the Toronto Drug Checking Service, publish summaries of their drug-checking results on a regular basis, including via email alerts.

Using the June 18 report, based on samples tested between May 31 and June 13, 2025, you will find that current drug samples may contain: 

Current Drug Supply 

• Fentanyl and fentanyl analogues: fentanyl is a high-potency opioid, used clinically for severe chronic pain including cancer pain and end-of-life pain, but is also the most common unregulated opioid. Fentanyl analogues are distinct drugs, that closely resemble fentanyl, but with minor chemical changes. Fentanyl analogues may be more or less potent than fentanyl itself. Examples include methylfentanyl and fluorofentanyl. Sanguen Health Centre supports the KW drug checking service and has a series of infographics about fentanyl and its analogues.  

• Non-fentanyl opioids are opioids and have similar effects to fentanyl, but are chemically different. Importantly, non-fentanyl opioids are not detectable by fentanyl test strips, but can be identified via drug-checking devices. Non-fentanyl opioids may be more or less potent than fentanyl itself. Examples include “nitazenes” such as protodesnitazene.  

• Benzodiazepines are drugs that are used clinically for sleep, anxiety, and seizure disorders. Examples include diazepam (Valium) and lorazepam (Ativan). Benzodiazepines have been increasingly found in unregulated opioid samples. These could be the same ones that are used clinically in Canada, benzodiazepines that are prescription drugs in other jurisdictions (e.g. etizolam) or have never been used clinically (e.g. ethylbromazolam, desaklylflurazepam). 

• Veterinary tranquilizers are also increasingly found in the unregulated drug supply. The most common are xylazine and medetomidine. Neither has been approved for human use. In addition to its sedating properties, xylazine, but not medetomadine, may cause serious skin ulcerations, even at sites distant from the injection site.  

A Note on Naloxone 

Naloxone is an opioid receptor blocker (as opposed to opioid receptor activators like fentanyl) that can be used to reverse the respiratory depression caused by opioids, which can be fatal. In cases involving an overdose involving one opioid, naloxone is quite effective. But what if someone takes too much of a mixture of opioids, benzodiazepines, and veterinary tranquilizers? The signs and symptoms, as well as the response to naloxone, may present differently.

The administration of naloxone is still recommended as it will reverse the opioid portion of the overdose. However, because naloxone does not affect the actions of benzodiazepine or veterinary tranquilizers, the individual may appear not to respond (i.e. remain unconscious) even though naloxone is working. This is one of the many reasons why all naloxone training and information emphasize calling 911 even before administering naloxone!  

Resources in Huron, Perth, Grey and Bruce

To learn more about drug services and educational sources that are currently available in the area, check out the following:

• Naloxone in the workplace | Ministry of Labour 

• Opioids | Health Canada 

• Opioids and painkillers | Ministry of Health 

• Recognize and temporarily reverse an opioid overdose | Ministry of Health 

• Grey Bruce Opioid Response Plan | Grey-Bruce Public Health

• Prescription Opioids Information Sheets | School Mental Health of Ontario

• Needle Exchange Program | Grey-Bruce Public Health

About Gateway Centre of Excellence in Rural Health 

Founded in 2008 in the community of Seaforth, ON, Gateway CERH is a not-for-profit rural health research organization run by a community-based volunteer board of directors. Gateway CERH's main mission is to better the health and quality of life of rural residents through research, education and communication. Learn more on the Gateway CERH website at: https://www.gatewayruralhealth.ca/ and follow us on Instagram, Facebook, LinkedIn and YouTube