How long a high lasts depends mostly on how you take it. Inhaled cannabis starts fast and fades in a few hours. Edibles start slowly and last much longer. Below are Health Canada's onset, peak and duration figures for each method, why edibles feel so different, and what can change the timing.
How long does a high last?
Health Canada's guidance on using cannabis products says that if you smoke or vape, you could feel effects for 2 to 4 hours. If you eat or drink cannabis, you could feel effects for 4 to 8 hours. These are ranges, not promises: they describe what people may experience, and your own timeline can run shorter or longer.
The same page adds an important caution. You may still feel some of the effects of cannabis, including impairment, up to 24 hours after smoking, vaping, eating, drinking or using cannabis under your tongue. A high that feels over can leave you less sharp than you think.
How long does each method take to kick in, peak and wear off?
That table is the quick answer. All three rows come from Health Canada's page on using a cannabis product. Its wording for the rows is "start to feel the effects", "could feel the strongest effects" and "could feel effects for", so they are ranges for typical use, not exact timers.
A separate Health Canada page, "Cannabis: lower your risks", gives the same picture in simpler terms. For smoking or vaping, effects can appear within seconds to minutes, and full effects can take up to 30 minutes. For edibles, effects can appear 30 minutes to 2 hours after consuming, and full effects can take up to 4 hours.
| Method | Starts to feel effects | Strongest effects | Could feel effects for |
|---|---|---|---|
| Smoking or vaping | Within seconds or minutes | After 10 to 30 minutes | 2 to 4 hours |
| Eating or drinking (edibles, drinks, oils) | Within 30 minutes to 2 hours | After 2 to 4 hours | 4 to 8 hours |
| Under the tongue (lozenges, sprays, oils, tinctures) | Within 15 to 40 minutes | After 1.5 to 4 hours | 12 hours |
How long do edibles take to kick in?
Health Canada says you might start to feel an edible within 30 minutes to 2 hours, with the strongest effects after 2 to 4 hours. The Ontario Cannabis Store gives a slightly wider onset window: it says effects from cannabis-infused products can be delayed from 30 minutes up to three hours.
The delay comes from digestion. An edible has to be swallowed, digested and processed before the THC reaches you, and that is slower than inhaling. The Ontario Cannabis Store lists body weight, sex, food eaten beforehand and metabolic rate as factors that affect the strength and length of effects, so two people can eat the same gummy and have different timelines.
This gap is why edibles catch people out. Eating more because "nothing is happening" is a common way to take too much. Health Canada's advice is to start low, go slow and wait to feel the effects before taking more. The Ontario Cannabis Store specifically says to wait at least two hours before ingesting more. If it goes too far, our guide to greening out covers the signs and what to do.
Why do edibles last so much longer than smoking?
Because the THC arrives gradually through digestion rather than all at once through the lungs. That's what Health Canada's figures show: edibles peak 2 to 4 hours in, against 10 to 30 minutes for inhaling, and can be felt for 4 to 8 hours against 2 to 4.
Some edibles are sold as "fast acting" or "quick onset". The Ontario Cannabis Store says these are meant to act sooner, but they tend not to last as long. Health Canada's figures don't separate them out, so check the package and still wait before taking more.
Under-the-tongue products sit in between on onset (15 to 40 minutes per Health Canada) but have the longest listed duration, 12 hours. That's one reason dose size matters so much for oils and tinctures.
How long does smoked or vaped weed last?
Smoking and vaping are the fastest. Effects can start within seconds or minutes, and the strongest effects come after 10 to 30 minutes. Health Canada says you could feel effects for 2 to 4 hours. Our guide to joints, spliffs and blunts covers smoked formats, and the vape pen guide covers vaping.
Because onset is quick, the standard advice is to take a small amount and wait. For flower, Health Canada suggests starting with 1 or 2 puffs of a product with 10% THC (100 mg/g) or less. Since full effects can take up to 30 minutes, waiting before the next puff gives you a more honest read.
Health Canada also says to avoid hash, kief, wax and shatter, especially for new or occasional users, as high THC content can cause greater impairment and serious adverse effects. Stronger products can feel more intense, and impairment can run longer.
What changes how long it lasts?
The method is the biggest factor, and dose comes next. Health Canada says the higher the dose of THC, the more likely you are to have side effects. The Ontario Cannabis Store adds body weight, sex, food eaten beforehand and metabolic rate. Tolerance and how you consume also play a part, but the sources above don't put numbers on them, so there's no reliable rule of thumb beyond "your own experience may differ".
THC strength matters because a stronger product delivers more per puff or per serving. The label shows Total THC for flower, and per-serving and per-package THC for edibles. If a number looks unfamiliar, see our guide to reading cannabis labels. For edibles, Health Canada notes that a package can hold up to 10 mg of THC in total and suggests looking for 2.5 mg or less per serving. Preparing your own edibles brings in extra variables, so see how to decarb weed for how heat activates THC.
When can you drive after using cannabis?
Plan around the longer figure, not the shorter one. Even if the strongest effects have faded, impairment can linger. Arrange another way home, wait it out, or choose a different time to consume. Check your province's rules on cannabis and driving before you plan anything.
What if it feels like too much?
Stop consuming, find a calm place, drink water and give it time. Because edibles last longer, an uncomfortable edible can run for hours, which is worth knowing before you eat one. Health Canada's duration figures are the best guide to how long it may take to fade.
For serious symptoms, such as difficulty breathing or loss of consciousness, call 911. For advice about a possible poisoning, Health Canada lists the poison centre at 1-844-POISON-X (1-800-463-5060 in Quebec). Our greening out guide has the full list of signs, sources and steps.