A cannabis high from smoking or vaping typically lasts 1 to 3 hours, while edibles can keep you high for 6 to 8 hours. Other substances vary widely, from under an hour for some to over 12 hours for others. The method you use, your body composition, and how often you use all shift that window significantly.
Smoked or Vaped Cannabis
When you smoke or vape cannabis, effects hit within seconds to minutes. The high usually peaks around 15 to 30 minutes in and tapers off over the next 1 to 3 hours. Dabbing concentrates sends THC blood levels much higher than flower, but interestingly, a University of Colorado Boulder study found that concentrate users didn’t report feeling proportionally more high, and measurable cognitive impairment faded within about an hour for both groups.
The rapid onset happens because THC passes almost instantly from your lungs into your bloodstream and reaches your brain within seconds. The trade-off for that fast hit is a shorter overall experience compared to eating cannabis.
Edibles
Edibles take 30 to 60 minutes to kick in, which is why inexperienced users sometimes make the mistake of taking a second dose before the first one hits. Peak blood levels of THC occur around three hours after you eat an edible, making the most intense point of the experience much later than with smoking. The full high generally lasts 6 to 8 hours.
This extended timeline exists because your liver converts THC into a different active compound that crosses into the brain more slowly but also lingers longer. Your metabolism, whether you’ve eaten recently, and your body fat percentage all influence how quickly that process plays out. Someone with a faster metabolism on an empty stomach may feel effects sooner, while someone with more body fat may experience a longer, more drawn-out high because THC is highly fat-soluble and gets absorbed into fatty tissue before being slowly released back into the bloodstream.
Why Duration Varies Between People
Two people can use the same product and have noticeably different experiences. The biggest factors are tolerance, body composition, and metabolism. Regular users build tolerance quickly, which shortens and dulls the subjective high. The plasma half-life of THC is 1 to 3 days in occasional users but stretches to 5 to 13 days in chronic users, meaning THC accumulates in your system over time even though you stop feeling high long before it clears.
Body fat plays a larger role than most people realize. THC is rapidly taken up by fat tissue, then slowly released back into the bloodstream. People with higher body fat may metabolize THC differently, and the slow release from fat stores is one reason residual effects can linger even after the obvious high is gone. Hydration, sleep, and individual liver enzyme activity also play smaller but real roles.
The “Afterglow” and Residual Effects
The high itself may last a few hours, but that doesn’t mean you’re back to baseline. Residual effects on attention, memory, and reaction time can persist well beyond the period when you feel intoxicated. Research published in Frontiers in Psychiatry found that measurable cognitive effects can last days or even weeks after the last use in regular users, particularly affecting learning and short-term memory.
For occasional users, these aftereffects are milder and shorter-lived. For daily users, deficits in attention and memory have been documented up to 3 to 4 weeks into abstinence. The encouraging finding is that these effects appear to be fully reversible with more than a month of not using, even in chronic users. If you feel foggy or slow the day after using cannabis, that’s a well-documented phenomenon, not just your imagination.
Alcohol
Alcohol reaches peak blood levels about 60 to 90 minutes after you start drinking. How long you feel the effects depends entirely on how much you consume, since your body processes roughly one standard drink per hour. The half-life of alcohol is four to five hours, and full elimination takes about 25 hours. So while the buzz from two drinks may fade in a couple of hours, a heavy night of drinking can leave alcohol in your system well into the next day, which is why morning-after impairment is a real concern for driving.
MDMA
MDMA effects begin about 30 to 45 minutes after swallowing a dose and typically last 4 to 6 hours. Some residual mood effects, both positive and negative, can continue for days afterward. The comedown from MDMA is notably different from other substances because it temporarily depletes your brain’s supply of mood-regulating chemicals, which can leave you feeling flat or low for a day or two after use.
Psilocybin Mushrooms and LSD
Psilocybin mushrooms produce effects lasting roughly 4 to 6 hours, with a relatively rapid onset. LSD lasts significantly longer at 8 to 12 hours. A study comparing equivalent doses of both substances found that despite the large difference in duration, the quality and intensity of the experience were similar at matched doses. The key practical difference is commitment: an LSD experience occupies most of a waking day, while psilocybin fits into an afternoon.
Both substances have what users describe as a gradual “coming down” phase in the final hours, where effects slowly diminish rather than cutting off sharply. Unlike cannabis, neither compound is fat-soluble in a meaningful way, so residual next-day effects tend to be more psychological than pharmacological.
Quick Comparison by Substance
- Smoked/vaped cannabis: onset in seconds to minutes, lasts 1 to 3 hours
- Cannabis edibles: onset in 30 to 60 minutes, lasts 6 to 8 hours
- Alcohol: peaks at 60 to 90 minutes, one drink clears per hour
- MDMA: onset in 30 to 45 minutes, lasts 4 to 6 hours
- Psilocybin mushrooms: lasts 4 to 6 hours
- LSD: lasts 8 to 12 hours