Since Toronto’s Drug Checking Service launched in 2019, we’ve consistently found benzodiazepine-related drugs contaminating Toronto’s unregulated fentanyl supply. The combination of these drugs is known to many as benzo-dope.
Over the past 5+ years:
- We’ve found 17 different benzodiazepine-related drugs in the fentanyl samples we’ve checked.
- We’ve found benzodiazepine-related drugs in 1 of every 2 fentanyl samples on average each month.
Despite finding a “new” benzodiazepine-related drug in Toronto’s unregulated fentanyl supply late last year (ethylbromazolam), we have observed a sharp decrease in the number of fentanyl samples containing benzodiazepine-related drugs since August 2024.
Between June 10 and 30, 2025, we didn’t find benzodiazepine-related drugs in any of the fentanyl samples we checked.
At this time, our data shows that benzodiazepine-related drugs are being replaced by veterinary tranquilizers medetomidine and xylazine in Toronto’s unregulated fentanyl supply. Many people refer to the combination of xylazine and/or medetomidine and fentanyl as tranq-dope. Like benzodiazepine-related drugs, veterinary tranquilizers are also central nervous system and/or respiratory depressants. Using high-potency opioids in combination with other central nervous and/or respiratory system depressants:
- Increases the risk of dangerous suppression of vitals, such as slowing down of breathing, blood pressure, heart rate.
- Complicates overdose response.
While benzo-dope increases the risk of harm and overdose for those using it, benzodiazepine-related drugs leaving the unregulated fentanyl supply has risks too. For example, since benzo-dope has been so common, many people who use fentanyl could also be dependent on benzodiazepine-related drugs. Suddenly stopping the use of benzodiazepine-related drugs could lead to life-threatening withdrawal.
We are continuing to monitor this trend and will keep the community informed as we learn more. To interact with our data, visit www.drugchecking.community.