Key points
• Contents of drugs from the unregulated supply are unpredictable, which increases the risk of harm to people who use drugs (PWUD) from this supply. Standardized information about drug contents is urgently needed to identify potential risks and inform harm reduction efforts.
• Through the Community Urinalysis and Self-Report Project (CUSP), data were collected from PWUD about reported substance use (via a self-report survey) and detected drug contents (via urinalysis). CUSP was implemented between 2019 and 2021 in seven regions across Canada.
• Stimulants were used most often compared with opioids and benzodiazepines. Cocaine/crack and methamphetamine/amphetamine accounted for most of the stimulant use. Most use of these stimulants were expected by participants (i.e., reported used when detected).
• Fentanyl was detected most often in British Columbia and Thunder Bay, where participants also usually expected its use. In other regions where fentanyl was detected least often (e.g., Manitoba, Nova Scotia), use was almost always unexpected (i.e., not reported used when detected). These differences must be considered when addressing opioid-related harms, which are largely driven by fentanyl.
• Benzodiazepine use was unexpected among at least 1 in 3 participants across sites. This was consistent with other information showing an increase in benzodiazepines in the unregulated drug supply since the COVID-19 pandemic began.
• A spectrum of harm reduction tools and supportive policies and programs tailored to the needs of PWUD in different communities are needed to improve drug predictability and reduce harms. These efforts may be informed by expanding and harmonizing research, monitoring and surveillance activities that examine drug contents, and the diverse experiences of PWUD.