A single edible can produce noticeable effects for 4 to 12 hours, but THC and its byproducts linger in your body far longer than the high itself. Depending on how often you use cannabis and which type of test you’re facing, traces can show up anywhere from 1 day to 90 days after your last edible.
How Long the High Actually Lasts
Edibles take 30 to 90 minutes to kick in, which is much slower than smoking or vaping. The effects build gradually, reaching their strongest point around 2 to 3 hours after you eat them. From there, the high tapers off, but the full experience typically lasts 6 hours or more. Higher doses and lower tolerance push that window closer to 12 hours.
This slow, extended timeline is one reason people accidentally take too much. The delay between eating and feeling anything leads some users to take a second dose, only to have both hit at once. Even after the noticeable high fades, subtle effects on coordination and reaction time can persist for several more hours.
Why Edibles Stay Longer Than Smoked Cannabis
When you eat cannabis, your liver converts THC into a metabolite called 11-hydroxy-THC, which is more potent and longer-lasting than the THC that enters your bloodstream through your lungs. This liver processing is why edibles hit harder and stick around longer. Cannabis that’s ingested generally remains detectable in your system slightly longer than cannabis that’s smoked.
After your body processes THC, it produces a secondary byproduct that is fat-soluble, meaning it gets stored in your body’s fat tissue and released slowly over time. Research from Johns Hopkins University found that this byproduct has a half-life of roughly 28 to 36 hours in a one-week observation window. With longer monitoring (14 days), the measured half-life stretched to 44 to 60 hours. That means it takes days for your body to clear even half of what a single dose produces, and the remainder trickles out over a much longer period.
Detection Windows by Test Type
The answer to “how long will it show up on a test” depends entirely on which test is being used. Here’s what to expect for each one.
Urine Tests
Urine testing is by far the most common method used by employers and probation programs. It doesn’t detect THC itself but rather the fat-soluble byproduct your liver creates. For someone who uses edibles once or very rarely, this byproduct typically clears within 3 to 4 days. Moderate users (a few times per week) can test positive for 7 to 21 days. Daily or heavy users may test positive for 30 days or longer, because THC byproducts accumulate in fat cells with repeated use and take weeks to fully flush out.
Your body composition matters here. People with higher body fat percentages tend to store more of these byproducts and release them more slowly. Hydration, metabolism, and exercise levels also play a role, though none of these factors can dramatically speed up the process.
Blood Tests
Blood tests detect THC itself, not its byproducts, so the detection window is much shorter. They typically pick up recent use within the last 2 to 12 hours. In heavy, chronic users, though, THC has been detected in blood up to 30 days later. Blood testing is less common for employment screening and more often used in medical or legal settings, like after a car accident.
Saliva Tests
Saliva testing has one of the shortest detection windows, generally picking up THC for about 24 to 48 hours after your last use. These tests are becoming more popular for roadside screening because they’re quick and non-invasive, but they’re less reliable for detecting edible use specifically since edibles don’t involve smoke or vapor passing through the mouth.
Hair Tests
Hair follicle tests have the longest detection window of any method: up to 90 days. As THC byproducts circulate in your blood, small amounts get deposited into growing hair follicles. A standard hair test analyzes the most recent 1.5 inches of growth, which represents roughly three months. Hair tests are less common but sometimes used for pre-employment screening in sensitive industries.
Factors That Affect How Long Edibles Stay
Two people can eat the same edible and have very different detection timelines. The biggest factor is frequency of use. Someone who eats an edible once at a party is in a completely different situation than someone who uses them daily for months. Daily users build up a reservoir of THC byproducts in their fat tissue, and that reservoir can take weeks to fully deplete.
Dose matters too. A 5 mg edible produces far less metabolite than a 50 mg one, which means it clears faster. Your metabolism, body fat percentage, age, and overall health all influence how quickly your body processes and eliminates these compounds. Younger people with faster metabolisms and lower body fat tend to clear THC more quickly, but there’s no reliable way to predict your exact timeline.
Despite what you might read online, drinking extra water, taking detox supplements, or exercising heavily right before a test won’t reliably help you pass. Vigorous exercise can actually release stored THC from fat cells into your bloodstream temporarily, which could work against you on test day.
How Long Impairment Lasts
The high from an edible and the actual impairment from an edible don’t end at the same time. You may feel “back to normal” while your coordination, reaction time, and judgment are still affected. The strongest impairment occurs around the 3-hour mark and can persist well beyond when you stop feeling high, especially with higher doses.
The CDC recommends not driving at all after using cannabis. If you’ve taken an edible, the safest approach is to wait at least 8 to 12 hours before driving, and longer for high doses. Planning a ride in advance or using a rideshare service eliminates the guesswork entirely.