Cannabis-related side effects: Key findings

Key findings regarding cannabis-related side effects in Canada.

  • Last updated: ...

During the reporting period (2018 to 2024), ... cases of side effects involving legal cannabis products were reported to Health Canada. We analyzed these cases and summarized the key findings on this page.

Throughout this dashboard:

  • Side effects are also referred to as adverse reactions. They're defined as “noxious and unintended response to a cannabis product” in the Cannabis Regulations. See Understanding the data for other definitions.
  • The reporting period refers to October 17, 2018 to December 31, 2024.

On this page

Summary of cases submitted between October 17, 2018 and December 31, 2024

... cases
... serious cases
... cases involving cannabis for medical purposes

Serious side effects and reason for cannabis use

Figure 1. of cases submitted to Health Canada over time by ,

Figure 1: Notes
  • For definitions, see the Understanding the data tab.
  • Seriousness is based on the initial report and may change if more information is submitted to Health Canada.
Figure 1: Text description

Note: use the "Filter items" search bar below to filter the table for information of interest. For example, to view data related only to the most recent year for which data is available, type ‘2023’ in the search bar.

  • A period (".") indicates that statistical significance was not calculated (when it appears in the "Significant difference from previous year" column) or that data was suppressed due to a low count (when it appears in the "Number" column).
  • A hyphen ("-") indicates that no previous year was available for comparison to the relevant row, so no significant difference from previous year could be calculated.

Side effects reported by age and sex

Figure 2. of cases submitted to Health Canada over time

Figure 2: Notes
  • If the year of birth and the date of reaction are listed in the report, the age is calculated.
  • If the year of birth is listed without a date of reaction, the report date is used to calculate the age.
  • Age groupings are aligned with the World Health Organization's Vigilyze database (Vigibase) categories.
Figure 2: Text description

Note: use the "Filter items" search bar below to filter the table for information of interest. For example, to view data related only to the most recent year for which data is available, type ‘2023’ in the search bar.

  • A period (".") indicates that statistical significance was not calculated (when it appears in the "Significant difference from previous year" column) or that data was suppressed due to a low count (when it appears in the "Number" column).
  • A hyphen ("-") indicates that no previous year was available for comparison to the relevant row, so no significant difference from previous year could be calculated.

Types of cannabis products involved

Figure 3. of cases submitted to Health Canada over time ,

Figure 3: Notes
  • Cases may involve multiple suspected cannabis products and different classes of cannabis product.
  • Cannabis extracts as a class include a diverse group of product forms including:
    • oral liquids/drops
    • softgels
    • capsules/tablets
    • sublingual sprays
    • dissolvable strips
    • highly concentrated extracts like shatter, wax, rosin, resin, or vaping liquids
  • Dried cannabis includes:
    • whole dried flower
    • milled flower
    • pre-rolls
  • Edible cannabis includes:
    • foods such as chocolate, confectionary, and mints
    • beverages
Figure 3: Text description

Note: use the "Filter items" search bar below to filter the table for information of interest. For example, to view data related only to the most recent year for which data is available, type ‘2023’ in the search bar.

  • A period (".") indicates that statistical significance was not calculated (when it appears in the "Significant difference from previous year" column) or that data was suppressed due to a low count (when it appears in the "Number" column).
  • A hyphen ("-") indicates that no previous year was available for comparison to the relevant row, so no significant difference from previous year could be calculated.

Outcomes

Figure 4. Number of times particular
were reported in cannabis side effect cases over time

Showing ... of ...

Select a system organ class on the vertical axis to explore data on the preferred terms relating to that system organ class. Click any preferred term to return to the original system organ class view.

Figure 4: Notes
  • Events are coded according to MedDRA based on the information in the case report. MedDRA provides standardized medical terminology in hierarchical groupings. The highest-level grouping is the System Organ Class (SOC) and the lowest level is the Preferred Term (PT).
  • Each case may describe 1 or more medical events and associated signs, symptoms, diseases, diagnoses, investigations, and procedures.
  • One side effect case may be represented across multiple SOCs, and is influenced by how individual events (signs, symptoms, observations, or diagnostics) are reported.
  • Each case can have multiple individual events reported, so the number of individual events exceeds the total number of cases.
  • Several types of hallucination were combined to create an all-inclusive hallucination category. These included auditory hallucination, visual hallucination, mixed hallucination, hypnagogic hallucination, and pseudohallucination.
  • The inclusion of a particular report in the database does not necessarily mean that the suspected product caused it. Further scientific investigation is needed to establish a cause-and-effect relationship between a cannabis product and a side effect.
Figure 4: Text description

Note: use the "Filter items" search bar below to filter the table for information of interest. For example, to view data related only to the most recent year for which data is available, type ‘2023’ in the search bar.

  • A period (".") indicates that statistical significance was not calculated (when it appears in the "Significant difference from previous year" column) or that data was suppressed due to a low count (when it appears in the "Number" column).
  • A hyphen ("-") indicates that no previous year was available for comparison to the relevant row, so no significant difference from previous year could be calculated.

We’ll continue to monitor these trends and investigate any longer-term impacts of legalizing and regulating cannabis in Canada. We’ll also continue to publish these data and use them to help inform educational and outreach resources for consumers and healthcare professionals.

Learn more

Read the full reports

Suggested citation

Health Canada. Summary of cannabis-related side effects: .... Ottawa: Health Canada; .... ...

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