Report a side effect to cannabis: Overview

On this page

• Classification of side effects
• Reasons to report side effects
• Who should report a side effect
• How to complete a side effect reporting form

Classification of side effects

The Cannabis Regulations (the Regulations) define an adverse reaction, also known as a side effect, as a noxious (harmful, unpleasant) or unintended response to a cannabis product. Side effects can be serious or non-serious.

Serious side effects

The Regulations classify a side effect as serious if it:

• requires in-patient hospitalization
• prolongs existing hospitalization
• causes congenital malformation
• results in persistent or significant disability or incapacity
• is life-threatening or results in death

When reported by a licence holder, medical and scientific judgement by a qualified professional, including a health care practitioner, should be used to determine if a side effect is serious.

Medically important side effects

Health Canada also considers medically important side effects to be serious. Medically important side effects may not be immediately life-threatening or result in death or hospitalization, but may:

• endanger the patient
• require intervention to prevent one of the other serious outcomes listed above

Reasons to report side effects

When you report a side effect, you contribute to the ongoing collection of important information about cannabis products that are on the market.

Your report is very important and may help:

• lower the risks of cannabis products marketed in Canada
• identify previously unrecognized, rare or serious side effects or problems
• identify potential risks of cannabis products to the health and safety of people in Canada
• contribute to international data about risks of cannabis products available for sale in Canada
• communicate new and emerging risks to industry, hospitals, health care providers and consumers in a timely manner
• undertake regulatory actions, such as changing the product label or removing a product from the Canadian market to mitigate any identified risk to people in Canada

Who should report a side effect

Voluntary reporting

The following groups are voluntary reporters under the Cannabis Act and its Regulations:

• hospitals
• consumers and patients
• health care professionals
• provincial and territorial retailers

Health Canada's ability to monitor health and safety issues with cannabis depends on voluntary reporting of side effects. You are encouraged to report any side effect involving cannabis regardless of:

• its source (for example, legal, illegal or unknown)
• its use with other suspect or concomitant products
• whether it's used for medical or non-medical purposes (that is, recreational purposes)

• Reporting for consumers or patients
• Reporting for health care professionals
• Reporting for hospitals

Mandatory reporting for licence holders

If you have a licence to sell or distribute a cannabis product, you are required to report all serious side effects (also known as serious adverse reactions) to Health Canada within 15 days of becoming aware of them per section 248.1 of the Regulations.

Reporting requirements for licence holders

If you are authorized to conduct non-therapeutic research on cannabis (NTRC), you are also required to report side effects. The requirements for NTRC are outlined in section 248.2 of the Regulations.

Reporting requirements for research licence holders authorized to conduct non-therapeutic research on cannabis (NTRC) studies

How to complete a side effect reporting form

You can report a side effect electronically. Use a separate form for each person (patient or consumer) who experienced a side effect. Include all suspect products in a single report if possible.

• Electronic forms
  • Consumers, patients or health care professionals
  • Hospitals
  • Licence holders

If you are using the printable form and you require an additional form to include more information or as a follow-up, indicate that it consists of follow-up information, including (if known):

• the date of the original report
• the original report reference number provided by Health Canada

All sections of the form should be filled in as completely as possible. To assist Health Canada in conducting thorough assessments of side effects, reports should include as much of the following information as possible:

• product information
  • brand name
  • lot or batch number
  • licence holder name
  • place and date of purchase
  • amount of THC or CBD and other ingredients such as other cannabinoids, terpenes or carrier oils
• details of use
• the amount used
• how the product was used (such as, route of administration)
• frequency and duration of product use, including start and stop dates
• other suspect products (such as, any products that may have caused or contributed to the side effect), if any
• concomitant health products or other substances taken at the time the side effect occurred but that may not have caused or contributed to the side effect
• consumer or patient medical history
  • whether they were new to cannabis or not
  • whether they previously consumed the suspected cannabis product
  • any previous known hypersensitivities or allergies to cannabis or other substances, including foods and health products
• description of the side effect, including date of onset and duration
• seriousness of the side effect and reason for seriousness
• information on whether the side effect stopped after cannabis use stopped (de-challenge) or returned when cannabis use resumed (re-challenge)
• outcome (for example, recovered or resolved, recovering)

Side effects associated with cannabis should be reported to Health Canada even if information is unknown or missing, particularly for side effects involving children, youth or older adults.