How Long Does a 5mg THC Edible Stay in Your System?

A single 5 mg THC edible clears your bloodstream within about a day, but its metabolites can linger in urine for roughly one to three days if you rarely use cannabis, and potentially much longer if you use it regularly. The honest answer depends heavily on which test you face, how often you consume cannabis, your body composition, and even your genetics. The gap between “no longer feeling high” and “no longer detectable” is wide, and that disconnect is where most confusion lives.

How Your Body Handles an Edible Versus Inhaled Cannabis

When you eat a 5 mg THC edible, the drug takes a slow, winding route compared to smoking. THC from an edible passes through your stomach and small intestine, gets absorbed into the bloodstream, and then travels to the liver before reaching the brain. In the liver, enzymes convert THC into 11-hydroxy-THC, an active metabolite that crosses the blood-brain barrier easily and contributes to the high. That metabolite eventually gets broken down further into THC-COOH, which is inactive but hangs around in your body much longer. THC-COOH is what most drug tests actually look for.

This liver-first processing means blood THC levels from edibles are generally lower than you might expect. In a controlled study of cannabis brownies, THC in blood was first detected about 30 to 90 minutes after eating, peaked between 90 minutes and two hours, and then declined steadily. Some participants who ate a 10 mg brownie never had detectable THC in their blood at all, despite consuming twice the 5 mg dose in question.¹ Meanwhile, the downstream metabolites like THC-COOH and its glucuronide form reached higher concentrations and were often still detectable at the final blood draw eight hours later.

That pattern matters for understanding detection windows. The parent drug (THC itself) leaves the blood fairly quickly after a single low-dose edible, but the metabolites your body produces from it persist much longer and are the real targets of most screening tests.

Urine Tests and the 5 mg Dose

Urine testing is by far the most common form of drug screening for employment, probation, and clinical settings, and it detects THC-COOH rather than THC itself. For someone who rarely uses cannabis, a 5 mg edible is about as low-risk as it gets for a standard urine test, but “low risk” is not the same as “no risk.”

In a study of infrequent cannabis users who received oral doses, specimens tested positive for THC-COOH at the common 15 ng/mL cutoff for a relatively short window. The vaporized 5 mg dose produced a mean last-positive-sample time of about 5.7 hours, and the oral 10 mg dose (the closest oral dose studied) showed a mean of about 6.5 hours at that cutoff.² Oral cannabis also produced positive results in a larger share of sessions: nearly all oral sessions resulted in at least one positive specimen, compared to about 60 percent of vaporized sessions. This makes sense because the liver-first metabolism of edibles generates more THC-COOH per milligram of THC consumed.

Most workplace drug tests use the federally mandated 50 ng/mL immunoassay cutoff, which is more than three times higher than the 15 ng/mL threshold used in that study. At the 50 ng/mL cutoff, a single 5 mg edible in someone who doesn’t otherwise use cannabis is unlikely to trigger a positive result, though it is not impossible depending on individual metabolism. Research on low-dose oral THC found that at the 50 ng/mL cutoff, detection rates were extremely low.³

For regular cannabis users, the math changes dramatically. Chronic use leads to accumulated THC-COOH stored in body fat, so the urine detection window has nothing to do with the last edible alone. Heavy daily users can test positive for weeks or even over a month after stopping, regardless of whether that last dose was 5 mg or 50 mg. The 5 mg dose question is really only meaningful for occasional or first-time users.

Blood Test Detection Windows

Blood tests look for THC itself, not just its metabolites, and the detection window is much shorter. After eating a cannabis brownie, THC in blood peaked between 90 minutes and two hours and then dropped off. The downstream metabolite THC-COOH stuck around longer and was frequently still present at the eight-hour mark, even at a 10 mg dose.¹ For a 5 mg dose, THC in blood would be expected to fall below common detection limits within several hours.

Research on oral cannabis pharmacokinetics found that whole blood THC was detectable from zero to 22 hours after dosing, though that range included higher doses.⁴ At 5 mg, a reasonable expectation for an infrequent user is that blood THC drops below standard limits within roughly 4 to 8 hours. But again, some individuals in these studies had no detectable blood THC even after eating 10 mg brownies, while others showed measurable levels for considerably longer. Individual variation is enormous.

Saliva Test Detection Windows

Saliva (oral fluid) testing has a quirk with edibles. When you eat a cannabis brownie, THC concentrations in saliva spike within the first 10 minutes or so, not because the drug has been absorbed and reached your salivary glands, but simply because the edible left THC residue in your mouth. Concentrations drop sharply after that initial spike.¹ The metabolite THC-COOH appeared in saliva after about 1.5 to 3 hours and peaked between 3 and 5 hours. For some participants, it was still detectable at 8 hours.

Studies on smoked cannabis show longer saliva detection windows, with THC detectable for up to 24 to 30 hours in occasional smokers and sometimes beyond 30 hours in frequent users.⁵ Edibles tend to produce lower peak saliva THC concentrations than smoked cannabis, so detection windows for a 5 mg edible are likely shorter. A conservative estimate for an infrequent user after a single 5 mg edible is roughly 12 to 24 hours, though roadside tests with lower cutoffs could extend that.

Why the Same Dose Doesn’t Hit Everyone the Same Way

If you have ever eaten a 5 mg edible with a friend and felt completely different effects, the research backs up your experience. Several biological factors alter how quickly your body breaks down THC and its metabolites.

Liver Enzyme Genetics

THC is primarily broken down by liver enzymes, and the genes controlling those enzymes vary between people. One key enzyme is CYP2C9. People who carry certain genetic variants of CYP2C9 clear THC and its metabolites more slowly, leading to a longer half-life and higher overall exposure from the same dose.⁶ In one study of oral cannabis users, the majority had at least one atypical variant in the relevant enzyme families: out of 71 patients, 31 had atypical CYP2C9 variants, 37 had CYP2C19 variants, and others carried variants in CYP3A4 or CYP3A5.⁷ In practical terms, this means the “average” detection window is genuinely average — many people fall outside it in both directions.

Sex Differences

Animal research and some human data suggest that biological sex affects THC processing. In a controlled mouse study, females had higher plasma THC and 11-hydroxy-THC levels after oral dosing, with peak THC concentrations roughly double those in males.⁸ Human data points in the same direction: in one study, females had a significantly higher peak blood concentration of THC compared with males after a 5 mg oral dose taken on an empty stomach.⁹ Higher peak concentrations could translate to slightly longer detection times, though the research on sex-based detection window differences specifically is still limited.

Food and Body Composition

Whether you eat the edible on a full or empty stomach changes absorption. The brownie study required participants to eat a standardized low-fat breakfast before dosing and then avoid additional food for at least 30 minutes afterward, specifically to reduce variability in absorption between participants.¹ In the real world, eating a fatty meal alongside your edible increases THC absorption, which raises both peak blood levels and the total amount of metabolite your body has to clear. That same human pharmacokinetic study confirmed that fed versus fasted conditions alter THC pharmacokinetics significantly.⁹

Body fat percentage also matters for the longer picture. THC is highly fat-soluble and accumulates in adipose tissue, where it persists for extended periods without being metabolized.¹⁰ For a single 5 mg dose in an infrequent user, fat storage is a minor issue. But for regular users, the fat reservoir is what makes detection windows stretch into weeks.

Can Exercise or Dieting Release Stored THC?

You may have heard that exercising or crash dieting before a drug test can cause stored THC to re-enter your bloodstream. The hypothesis is real and has biological grounding: conditions that promote fat breakdown, such as fasting, stress, and intense exercise, could theoretically release THC that has been sequestered in fat tissue back into the blood.¹¹ Animal studies have shown this effect directly: food deprivation in rats increased blood THC levels from fat stores.¹⁰

For someone who ate one 5 mg edible last week, this effect is almost certainly irrelevant. The amount of THC deposited in fat from a single low dose is tiny. But if you are a regular user who has recently stopped and you are trying to clear a drug test, aggressive exercise or a crash diet right before testing could plausibly bump your metabolite levels slightly. Whether that small bump would push a borderline result from negative to positive depends on many factors, but most researchers consider the effect modest in real-world human terms.

How CBD in the Edible Can Extend Your Detection Window

Many commercial edibles contain both THC and CBD, and this combination has a surprising pharmacokinetic consequence. CBD inhibits some of the same liver enzymes that break down THC, which results in higher and longer-lasting THC levels in your blood. A randomized clinical trial found that when THC was taken with CBD, the peak blood concentration of THC rose substantially, and the peak of the active metabolite 11-hydroxy-THC jumped by roughly tenfold compared to THC taken alone.¹² The total area under the curve for THC-COOH, the metabolite that drug tests target, also increased significantly.

This means a 5 mg THC edible that also contains a meaningful dose of CBD could behave more like a higher-dose THC-only product in terms of detection. If you are concerned about a drug test, the CBD content of your edible is worth paying attention to.

Feeling Sober Doesn’t Mean You’re Clear

After a 5 mg edible, most people feel the effects wear off within about four to six hours. Research on oral cannabis confirms that subjective effects and cognitive impairment are generally dose-dependent, peaking at about 1.5 to 3 hours after eating and lasting roughly 6 to 8 hours.⁴ At 5 mg, the impairment is fairly mild for most people. A study looking specifically at dose-dependent effects found that 10 mg produced noticeable subjective effects and elevated heart rate in infrequent users but did not significantly alter cognitive or psychomotor performance. Higher doses of 25 and 50 mg clearly impaired both.¹³ Separately, research has identified that oral THC above a 2.5 mg bolus produces blood levels sufficient to impair psychomotor function in average healthy adults.¹⁴

The important takeaway for driving is that THC blood levels from edibles stay low even when the person is impaired. A clinical trial of edible cannabis and driving found that mean blood THC peaked at only about 1.6 ng/mL after a 10 mg dose, well below common legal thresholds of 5 ng/mL. Yet participants showed clear driving impairment and reported altered subjective experience for up to seven hours.¹⁵ Of nearly 300 blood samples tested, only 8 exceeded the 5 ng/mL threshold. Edibles create a situation where you can be genuinely impaired but pass a blood-level-based legal test, or conversely, have lingering metabolites in your urine while feeling completely fine. Neither direction maps neatly onto actual safety.

False Positives on Immunoassay Screens

Standard workplace and clinical urine drug screens use immunoassay technology, which works by detecting antibodies that react with THC metabolites. These antibodies are not perfectly specific. Certain prescription and over-the-counter medications can cross-react with the cannabinoid antibodies used in these tests, producing a positive result even in someone who has never used cannabis. A review of false-positive interferences published between 2013 and 2024 identified numerous medications that can trigger false positives across several drug classes, including cannabinoids.¹⁶ If you are taking proton pump inhibitors such as pantoprazole, certain NSAIDs like ibuprofen at high doses, or the antiviral efavirenz, a false positive for cannabinoids is possible. A confirmatory test using gas chromatography-mass spectrometry or a similar method can distinguish a true positive from a cross-reactive false one, so if you get a surprising result and know you haven’t used cannabis, requesting confirmation testing is reasonable.

THC Fat Storage at the Molecular Level

THC’s extreme fat solubility is what makes it unique among recreational drugs in terms of detection persistence. Animal research has shown that high concentrations of THC accumulate in several fat deposits, with gonadal fat storing particularly elevated levels. These concentrations persisted for hours without significant metabolism, while THC in the liver, lungs, and other tissues declined as the body actively broke it down.¹⁷ Fat tissue essentially acts as a slow-release reservoir. For a single 5 mg dose, this reservoir receives a small deposit that clears relatively quickly. But with repeated dosing, the deposits accumulate and take proportionally longer to empty, which is why the distinction between occasional and regular user matters so much more than the size of any single dose.

In continuous high-dose oral THC studies, plasma THC concentrations remained above 1 microgram per liter for at least a full day after the last of multiple oral doses, and the inactive metabolite THC-COOH reached much higher concentrations that persisted even longer.¹⁸ This gives a sense of scale: chronic dosing produces a metabolite backlog that dwarfs anything a single 5 mg gummy could create.