The short answer: it depends.
An edible high can last anywhere from 1 - 10+ hours.
How long it lasts depends on a range of factors such as:
your tolerance to cannabis
how much THC is in it
how much of it you took
your body weight and metabolism
the last time you ate and your level of satiety
How Long Do Edibles Take to Kick In?
Cannabis edibles can take anywhere between thirty minutes to a few hours to kick in, but the average time is between 30-60 minutes.
THC is processed differently when you eat it versus when you smoke it. When your liver processes edibles, it converts the THC in the edible from Delta-9 THC to 11-hydroxy THC.
This changes the composition of THC to a different drug. 11-Hydroxy THC tends to release erratically and can be different from person to person and can take upwards of 2-3 hours to come into effect.
To explain it in short, everybody processes edibles differently.
Tip: A common mistake for newcomers to edibles is not waiting long enough for the edible to kick in and taking more. And then suddenly it hits, and they are too high. A good rule of thumb for edibles is “Start low and go slow.”
How long the effects of an edible will last also depend on your body, but here are some things to keep in mind about the longevity of an edible:
Because you are absorbing the weed through your digestive system rather than your lungs, it will take longer to kick in. Depending on your digestion rate, the entire process to “feel” the edible could take anywhere between 45 minutes and three hours.
The peak usually lasts anywhere from two to five hours. Depending on your dosage, you should be careful about what activities you attempt to take on during that time, like driving or operating heavy machinery.
The total amount of time it is in your system is longer than you will feel high—there will be a period of after-effects that stretches potentially up to 12 hours. You will feel high after six hours, but it will not be as close to peak hours.
Even with the same edibles, your experiences might differ from one time to the next. It will depend on a variety of factors, so you should always start slow.