Toronto health officials are raising alarms after new data revealed record levels of the ultra-potent opioid carfentanil in the city’s illicit drug supply. The Toronto Drug Checking Service, a program operated by local hospitals and community health centres, reported that 14 per cent of samples tested recently contained carfentanil — the highest detection rate since the program launched in 2019.
Carfentanil is up to 100 times stronger than fentanyl and was originally developed as an anesthetic for large animals such as elephants and rhinoceroses. Despite being rare in street drugs, it contributed to 35 per cent of accidental opioid overdose deaths in Toronto in 2019. The renewed surge has prompted concerns of heightened overdose risks.
“The biggest concern about carfentanil is its strength,” said Karen McDonald, executive director of the Toronto Drug Checking Service. “Because the drug is so strong, the chances of overdose may be increased.” She noted that the drug is increasingly being detected not only in Toronto, but also in Kingston, Peterborough, and Thunder Bay, as well as in other provinces and U.S. states.
Experts suggest traffickers may be turning to stronger opioids because they are easier to package and transport amid law enforcement crackdowns. McDonald added that carfentanil’s presence is particularly troubling because it often appears mixed with other potent opioids and central nervous system depressants, making overdoses more complex to treat. Higher doses of naloxone may be required to reverse its effects, and even then, naloxone alone may not be enough.
Officials also noted the resurgence comes as fewer drug samples are being submitted, following the closure of several supervised injection sites. “Our sample volumes are down, yet the number of samples that contained carfentanil are up,” McDonald said, underscoring the severity of the risk.
The findings reinforce growing concerns that Canada’s opioid crisis is entering a more dangerous phase, with carfentanil’s deadly potency threatening to drive overdose deaths even higher.