Cannabis-related side effects: Understanding the data

On this page

• Context
• Definitions
• Data source
• Data considerations

Context

The Cannabis Act and its regulations came into force on on October 17, 2018, thereby legalizing and regulating cannabis in Canada for non-medical purposes. A key component of our public health approach is to monitor cannabis use patterns and side effects. To achieve this, we set up the Vigilance Framework for Cannabis, which allows us to detect, collect, monitor, and assess the side effects of cannabis. It supports decision-making (including compliance, enforcement, and policy) and communication of the health and safety risks of cannabis to the public.

Side effects of various products, including cannabis, are submitted to Health Canada via the Canada Vigilance Program. Cannabis-related side effects are voluntarily submitted by consumers, patients, health professionals, provincial and territorial authorized retailers, and others. Licence holders must report serious side effects involving cannabis products to Health Canada per the Cannabis Regulations. Licence holders may submit non-serious side effects voluntarily.

Definitions

The following definitions describe how we use these terms in this framework and on this dashboard.

Cannabis product

Cannabis of any class described in Schedule 4 to the act (or an accessory containing such cannabis) that has been packaged and labelled for retail sale to a consumer.

Medical purposes

Cases involving cannabis use for medical purposes include:

• those described as having a medical authorization document
• those with a reported medical or therapeutic purpose, without mention of a medical authorization document

This is broader in scope than the regulatory definition of cannabis for medical purposes under the Cannabis Regulations.

Non-medical purposes

Cases involving cannabis use for non-medical purposes include:

• cases with no reported medical or therapeutic indication or reason for use provided in the report
• cases where the intended use is for non-medical purposes (for example, recreational)

Side effect

Side effect is referred to as an ‘adverse reaction’ within the Cannabis Regulations and is defined as “a noxious and unintended response to a cannabis product”.

Serious side effect

A serious side effect is defined as a noxious and unintended response to a cannabis product that:

• requires inpatient hospitalization or prolongs an existing hospitalization
• causes birth defects
• results in persistent or significant disability or incapacity
• is life-threatening or results in death
• requires medical intervention to prevent any of the above outcomes (refer to "medically important condition" in the cannabis adverse reaction reporting guidance)

Data source

This dashboard uses data from the Canada Vigilance post-market surveillance program, which collects reports of suspected side effects to health products, including cannabis. Reports involving cannabis are further assessed by Health Canada.

The cases included in this summary are available in the Canada Vigilance database for cannabis products. The database is updated monthly to include reports received up to 90 days before the posting date.

Data considerations

• This data doesn't represent all cannabis-related side effects experienced by Canadian consumers. Side effects from cannabis are not consistently reported by consumers and can't be used to determine how common they are in the general population.
• This analysis focuses on cases suspected of involving legal cannabis products. Cases involving home grown cannabis, unregulated cannabis, or cannabis from an unknown source are excluded.
• Serious side effects are better represented in this dataset as cannabis license holders must report them to Health Canada. License holders may report non-serious side effects voluntarily. As a result, non-serious side effects are likely underreported and underrepresented in this dataset.
• Reporting of side effects by non-license holders (such as consumers and health care professionals) is voluntary for cannabis products. Therefore, it’s likely that both serious and non-serious cases from these sources are underreported.
• Several factors may also influence the number of cases reported, such as:
  • consumer medical history
  • seriousness of the report
  • reason for cannabis use
  • length of time a product is on the market
  • media coverage
  • awareness, motivation, and ability to report
  • nature of report (for example, spontaneous reports versus studies or other organized data-collection systems)
• The inclusion of a report in the database doesn't necessarily mean that the cannabis product caused the adverse event. More scientific investigation is required to establish a cause-and-effect relationship.

Related links

• Canada Vigilance Program
• Data on cannabis-related side effects
• Reporting side effects to cannabis