Fentanyl

An opioid used in medicine that also appears in unregulated drug supplies. Opioid poisoning can slow breathing to life-threatening levels; pharmaceutical use and unregulated exposure are distinct contexts.

Evidence as of 2025

Sources

1. The Emergence of Opioids in Canada ? Health Canada; 2025
2. Opioids ? National Institute on Drug Abuse; publication date unspecified

Historical and attributed reference. A source mention is not proof of current activity.