Last reviewed October 18, 2026
Health Canada’s lower-risk guidelines recommend waiting at least 6 hours after using cannabis before you drive, and longer after edibles or a large dose. That’s a minimum. Impairment varies by person and product, some effects can last up to 24 hours, and the law applies however long ago you consumed.
The simple rule: if you feel any effect at all, don’t drive. Plan your ride home before you start.
How long effects last
| Smoking or vaping | Edibles and drinks | |
|---|---|---|
| Main effects | Up to 6 hours | Up to 12 hours |
| Some residual effects | Up to 24 hours | Up to 24 hours |
With edibles, effects can still be building 4 hours after you eat, so waiting 6 hours from the moment you ate may not be enough.
What the law says
Driving while impaired by drugs, alcohol or both, to any degree, is a criminal offence in Canada. The Criminal Code also sets blood limits for THC, measured within 2 hours of driving:
| Level | Offence |
|---|---|
| 2 ng to under 5 ng of THC per ml of blood | A less serious offence, with a fine of up to $1,000 |
| 5 ng or more per ml | Impaired driving: a $1,000 minimum fine for a first offence, with jail for repeat offences |
| 2.5 ng THC per ml plus 50 mg of alcohol per 100 ml of blood | Same penalties as the 5 ng limit |
Many provinces add their own rules, including zero tolerance for new, young and commercial drivers. This page is general information, not legal advice.
Things that make it riskier
- Mixing with alcohol: the combination impairs more than either alone.
- Edibles: slower to start and longer to wear off.
- Concentrates and dabs: higher doses, stronger effects.
- Feeling fine: reaction time and judgement can be affected before you notice anything.
Getting home
Use a designated driver, a taxi or rideshare, or public transit, or stay where you are. Don’t get in a car with a driver who has used cannabis.
Common questions
How long after smoking cannabis can you drive?
Health Canada’s guidelines say at least 6 hours, as a minimum. Longer after edibles or high doses, and never while you feel any effect.
Is it illegal to drive high in Canada?
Yes. Driving while impaired by cannabis is a criminal offence, with set THC blood limits on top.
How long after an edible can you drive?
Longer than after smoking. Edible effects can last up to 12 hours, with some lasting up to 24.
Can you be over the limit without feeling high?
Yes. THC in the blood doesn’t line up neatly with how impaired you feel, especially for regular users.
Sources: Health Canada, Fact sheet about lower-risk cannabis use guidelines and What you need to know if you choose to consume cannabis; Department of Justice, Impaired driving laws.
