A cannabis high typically lasts 1 to 3 hours when smoked or vaped, and up to 12 hours when consumed as an edible. The actual duration depends on how you consume it, how potent the product is, and how your individual body processes THC. Those are broad ranges, though, and the details matter quite a bit depending on your situation.
Smoking and Vaping: 1 to 3 Hours
When you inhale cannabis, whether through a joint, pipe, bong, or vape pen, the effects hit within minutes. THC passes from your lungs directly into your bloodstream and reaches your brain almost immediately. The high peaks shortly after you finish inhaling and then gradually tapers off. Most people feel the primary effects for 1 to 3 hours, though some lingering effects can stretch to 8 hours depending on potency and how much you consumed.
Research from the National Institute of Justice found that for vaped THC doses over 5 mg, peak cognitive and psychomotor effects occurred within the first two hours and returned to baseline after about four hours. So even if you still feel slightly “off” after the high fades, your mental sharpness is likely back to normal within that four-hour window for inhaled cannabis.
Edibles: 4 to 12 Hours
Edibles are a completely different experience. It takes 30 minutes to 2 hours just to start feeling anything, and the full effects can take up to 4 hours to arrive. This long ramp-up is why people sometimes make the mistake of eating more before the first dose kicks in, leading to an unexpectedly intense experience.
Once the high does peak, it can last up to 12 hours, with residual effects lingering up to 24 hours into the next day. The reason edibles hit harder and last longer comes down to how your liver processes THC. When you eat cannabis, your liver converts THC into a different active compound that binds more tightly to receptors in your brain and crosses into the brain more easily than THC itself. This metabolite is roughly 1.5 times as potent as the THC you originally consumed. On top of that, both THC and this metabolite dissolve into fatty tissue throughout your body and release slowly over time, which is why the effects drag on for so many hours.
NIJ research confirms the timeline: for oral THC doses, cognitive and psychomotor effects appeared about one hour after consumption, peaked around five hours in, and didn’t return to baseline until eight hours had passed.
Concentrates and Dabs
Cannabis concentrates (wax, shatter, dabs) contain 40 to 80 percent THC, compared to around 20 percent for high-grade flower. That’s up to four times stronger. The onset is nearly instant when vaped or dabbed, similar to smoking flower, but the intensity is significantly greater. Because of the higher THC load entering your system at once, the effects can feel more overwhelming and may take longer to fully clear, particularly for people without a high tolerance.
Delta-8 vs. Traditional THC
Delta-8 THC, which is sold in many states where traditional cannabis isn’t legal, produces a milder high. Its psychoactive strength is roughly half to two-thirds that of regular (delta-9) THC. Users generally report a shorter, less intense experience, though the overall timeline of onset and decline follows similar patterns depending on whether you inhale or ingest it.
Why the Same Product Hits People Differently
Your body’s genetics play a larger role than most people realize. About one in four people carry a gene variant that causes the enzymes responsible for breaking down THC to work less efficiently. If you’re in that group, the same dose will hit you harder and last longer than it does for someone else. This is one reason two people can share the same edible and have wildly different experiences.
Beyond genetics, several other factors shift the timeline:
- Tolerance. Regular users build tolerance and typically experience shorter, less intense highs from the same dose.
- Body composition. THC is fat-soluble, meaning it gets stored in fatty tissue and releases slowly. People with higher body fat percentages may experience longer-lasting effects and longer detection windows.
- Dose. This is the most controllable variable. A single puff of mid-grade flower is a fundamentally different experience from a 50 mg edible, both in intensity and duration.
- Empty stomach. Consuming edibles without food can speed up absorption and intensify the effects.
How Long Impairment Actually Lasts
Feeling “back to normal” and actually being back to normal aren’t always the same thing. The subjective high fades before all cognitive effects do. For inhaled cannabis, mental sharpness typically returns to baseline within four hours. For edibles, that window extends to about eight hours. During this period, reaction time, attention, and decision-making can all be affected even if you no longer feel high.
One important finding from NIJ research: THC levels in your blood, urine, or saliva don’t reliably indicate whether you’re actually impaired. Many study participants showed significant decreases in cognitive and motor function even when their THC levels tested low. This means you can’t use a “feeling fine” self-assessment or even a blood test as proof that you’re good to drive or handle tasks that require full concentration.
The Day-After Hangover Effect
Some people notice a foggy, sluggish feeling the morning after using cannabis, especially after edibles or high doses. This isn’t the same as still being high, but it reflects THC and its metabolites still clearing from fatty tissue in your brain and body. For occasional users, this typically resolves within a day. For people who use cannabis regularly over long periods, the fog can become more persistent, showing up as lowered motivation, difficulty learning new information, or trouble sustaining attention. If you’ve been a regular user and decide to cut back, it can take up to a month before cognitive improvements become noticeable, since cannabis can remain stored in your body for two to four weeks.