Lower-Risk Cannabis Use Guidelines
A summary of ten recommendations for lower-risk cannabis use:
Abstinence is the most effective way to avoid cannabis use-related health risks
Cannabis use should not be started early in life (i.e. definitively avoid use before the age of 16)
Choose low-potency tetrahydrocannabinol (THC) or balanced THC-to-cannabidiol (CBD)-ratio cannabis products
Do not use synthetic cannabinoids
Avoid combusted cannabis inhalation; give preference to non-smoking use methods
Avoid deep or other risky inhalation practices
Avoid high-frequency (e.g., daily or near-daily) cannabis use
Do not drive while impaired by cannabis
Populations at higher risk for cannabis use-related health problems should avoid use altogether
Avoid combining previously mentioned risk behaviors (e.g., early initiation and high-frequency use).
Full paper is available here:
Fischer B, Russell C, Sabioni P, van den Brink W, Le Foll B, Hall W, et al. Lower-Risk Cannabis Use Guidelines: A Comprehensive Update of Evidence and Recommendations. Public Health Policy. 2017;107(8):e1-e12.
Edibles and Other Newly Legal Forms of Recreational Cannabis
As of October 17, 2019, cannabis extracts, topical cannabis products, and cannabis edibles are legal in Canada. They will be available for sale in licenced dispensaries and online through the Ontario Cannabis Store in December 2019.
Cannabis extracts are concentrated cannabis products that can be smoked, vaped, or ingested. They contain higher levels of cannabinoids (like THC and CBD) than the cannabis plant contains naturally. Some extracts can be very high in THC; others can mainly contain CBD. Waxes, dabs, and shatters are all examples of cannabis extracts.
Cannabis topicals are products like oils, creams, and lotions that contain cannabinoids and are intended for use on the skin, hair, or nails. Cannabis topicals are most commonly used for therapeutic or cosmetic purposes rather than to achieve a “high.”
Cannabis edibles are food or drink items that contain cannabinoids and are intended for ingestion.
For more information about the newly legal forms of Cannabis in Canada, see the Primer on New Cannabis Products from the Canadian Centre for Substance Use and Addiction (CCSUA).
Special Considerations for Edible Cannabis Products
THC, the primary psychoactive component in cannabis, is metabolized differently when it is ingested vs. inhaled. It takes longer to feel the effects of edibles, and the effects typically last longer.
Because of the delayed effects, inexperienced users can be inclined to dose-stack edible cannabis products, which poses a risk for unintentional over-intoxication. Users should give special consideration with respect to driving after consuming edibles (because of the delayed and prolonged effect), and to storing edibles safely to avoid accidental ingestion by children and others.
For more information on edible cannabis and its risks, see the following resources:
Special Risk Populations
Cannabis may not be suitable for all patients. Several publications from Health Canada, the CFPC, and others have identified a set of special risk populations in the context of both medical and recreational cannabis use:
Women who are pregnant, breastfeeding, or planning to become pregnant
Children and youth under the age of 25
Individuals with current, past, or family history of psychosis
Individuals with current, past, or family history of substance use disorder
NOTE: Risks to Mental Health
Growing evidence also shows that cannabis use increases the risk of psychosis and psychotic disorders for the general population (not just for those with a history of, or predisposition to psychosis or psychotic disorders).
For a detailed overview of the risks of cannabis use in the populations listed above, and links to position statements from the relevant medical societies, visit our
Cannabis and Special Risk Populations page
Cannabis and Driving
Information to help you understand the new laws around cannabis-impaired driving, discuss the risks with patients, and understand your responsibilities.
Cannabis-Related Health care Visits
Marijuana Decriminalization: The Colorado Emergency Department Experience
Toxicologist and Emergency Medicine physician Dr. Kennon Heard draws from the experience of emergency departments in Colorado to comment on the factors that have contributed to the rise of cannabis-related visits to the ER.
He addresses the pharmacology of cannabis and offers practical advice to help Ontario’s Emergency Medicine physicians better prepare for and manage the following cannabis-related
Accidental pediatric ingestion
Synthetic cannabinoid overdoses
PDF Reference Document
Updated: October 15, 2019