How Long Does Vape Stay in Your System?

The answer depends on what you vaped and what kind of test you’re facing. Nicotine itself clears from your blood within hours, but its main metabolite, cotinine, lingers for days and is what most nicotine tests actually detect. THC from cannabis vapes follows a completely different timeline, staying detectable in urine for days to weeks depending on how often you use it. The substance, your biology, the type of device, and the testing method all shift the window considerably.

How Quickly Nicotine Enters and Leaves Your Blood

When you inhale from a vape, nicotine reaches peak blood concentration fast. Studies of experienced e-cigarette users show plasma nicotine levels peaking within about two to five minutes of the last puff, with average peak concentrations around 8 ng/mL.¹ That speed is comparable to smoking a traditional cigarette, though peak levels from vaping tend to be somewhat lower on average. Your body retains the vast majority of what you inhale: roughly 94% of the nicotine dose gets absorbed systemically.

Nicotine has a half-life of about two hours, meaning the amount in your blood drops by half every couple of hours after you stop vaping. Within eight to twelve hours, most of it is gone from your bloodstream. But that doesn’t mean you’re in the clear on a test, because your liver has already been converting nicotine into something longer-lived.

Cotinine Is What Tests Actually Look For

Your liver breaks down nicotine primarily through an enzyme called CYP2A6, which converts it into cotinine.² Cotinine has a much longer half-life than nicotine, typically around 16 to 20 hours, which makes it the preferred target for drug testing. Most workplace and insurance nicotine screenings measure cotinine rather than nicotine itself because it provides a wider detection window and is harder to dodge by simply abstaining for a few hours.

For a light or occasional vaper, cotinine generally clears from blood and urine within three to four days after the last use. For heavier, daily vapers, that window stretches to closer to a week or sometimes longer, because cotinine builds up with repeated dosing. In saliva, cotinine can be detected at meaningful levels for a similar timeframe. One study of pregnant women established detection cutoffs for cotinine at about 13 ng/mL in saliva and 42 ng/mL in urine, giving a sense of the thresholds labs use to distinguish active users from background noise.³

Hair testing is the outlier. Nicotine and cotinine deposit into hair as it grows, and because hair grows slowly, a standard hair test covering about 1.5 inches of growth from the scalp can detect nicotine use from roughly the past 90 days. This makes hair the longest detection window by far, though hair tests for nicotine are less common outside of research settings and certain insurance screenings.

How Your Vape Device Changes the Equation

Not all vapes deliver nicotine equally, and the differences matter for how much ends up in your system. The two biggest variables are nicotine concentration and whether the liquid uses nicotine salt or freebase nicotine. Nicotine salt formulations, the kind found in most pod-style devices, deliver substantially more nicotine per puff. A crossover study found that vaping nicotine salt at the same concentration as freebase produced a peak blood level about 1.8 times higher, and total nicotine exposure was 46% greater.⁴ Higher-concentration salt e-liquids (like the 40-50 mg/mL pods common in many popular devices) push peak levels even higher, with one study recording median peak serum nicotine of 12 ng/mL for a 40 mg/mL salt formulation.

This matters because more nicotine absorbed means more cotinine produced, which means a longer detection window. Someone taking a few puffs from a low-power freebase device at 3 mg/mL is putting far less nicotine into their body than someone chain-vaping a high-concentration salt pod. The first person might clear a cotinine test in two or three days; the second might need a week.

Device power and how you inhale also play a role. Higher wattage devices vaporize more liquid per puff, delivering more nicotine even at the same liquid concentration. Nicotine absorption in your airways is also affected by aerosol temperature and how quickly you inhale.⁵

Why Some People Clear Nicotine Faster Than Others

The speed at which your body processes nicotine varies more than most people realize, and genetics is the biggest driver. The CYP2A6 enzyme that converts nicotine to cotinine comes in several genetic variants. Some people carry versions that work much faster than average, while others have slow or even nonfunctional copies. Studies have found that the nicotine metabolite ratio, a measure of how quickly your body converts nicotine, is strongly associated with CYP2A6 genotype, sex, and age.⁶ Women tend to metabolize nicotine faster than men, in part because female livers show higher CYP2A6 protein and gene expression.⁷

There’s a practical irony here. Fast metabolizers clear nicotine from their blood more quickly, which sounds like it would help on a test. But fast metabolism also means they convert nicotine to cotinine more efficiently, which is the metabolite actually being measured. The net effect on detection windows is modest, though very slow metabolizers do tend to have cotinine linger a bit longer because they also clear cotinine more slowly overall.

Kidney function matters too. Nicotine and cotinine are partly eliminated through the kidneys, and people with impaired kidney function clear both substances significantly slower. One study found that nonrenal clearance of nicotine was roughly halved in people with severe kidney failure compared to healthy subjects, and cotinine elimination was also delayed.⁸ If you have kidney disease, expect longer detection windows for any nicotine product.

THC from Cannabis Vapes Follows Different Rules

If you’re vaping cannabis rather than nicotine, the detection timeline is an entirely different story. THC is fat-soluble, which means it doesn’t just pass through your blood and kidneys the way nicotine does. Instead, it gets absorbed into fat tissue and then slowly released back into your bloodstream over time.

After vaping cannabis, THC peaks in your blood very quickly, typically within the first 10 minutes. Vaporized cannabis actually produces higher blood THC concentrations than smoking the same dose, likely because vaporizers extract cannabinoids more efficiently from the plant material.⁹ THC in blood drops relatively quickly over the first few hours, often falling below detectable levels within three to six hours for infrequent users. One study of vaporized CBD-dominant cannabis (which contained some THC) found that blood THC was no longer detectable three hours after use for any participant.¹⁰

But blood clearance is misleading if you’re worried about a urine test. Urine screens don’t measure THC directly. They measure THC-COOH, a metabolite your liver produces, and particularly its glucuronide conjugate. These metabolites accumulate and are excreted slowly, especially with repeated use. For occasional users, a single vaping session might produce a positive urine result for one to three days. For frequent users, urine tests can come back positive for weeks or even over a month after the last use, because THC-COOH keeps leaking out of fat stores.¹¹ That study found that the percentage of positive urine results for frequent users approached 100% across all routes of administration, reflecting both their more efficient inhalation technique and the ongoing excretion from accumulated stores.

Oral fluid (saliva) testing for THC tells yet another story. THC can be detected in saliva for up to 24 to 30 hours after a single smoking or vaping session, with no major difference between frequent and occasional users over the first 30 hours.¹² Saliva tests are increasingly used in roadside drug testing, where the window of detection is meant to capture recent impairment rather than historical use.

The Fat-Storage Problem with THC

THC’s fat solubility creates a quirk that nicotine users never deal with. Once THC accumulates in your fat tissue from repeated use, it can be re-released into your bloodstream during periods of fat burning. Animal research has demonstrated that both food deprivation and stress hormones enhanced the release of THC and THC-COOH from fat stores back into blood in subjects that had been previously exposed to THC.¹³ This raises the possibility that crash dieting, intense exercise, or high stress before a drug test could temporarily bump your THC-COOH levels upward rather than helping you clear them.

This is why body composition is such an important variable for THC detection. A person with more body fat has more storage capacity for THC. After they stop using, those fat stores act as a slow-release reservoir, extending the detection window. A lean occasional user might test clean within days, while a heavier frequent user might test positive for a month or longer from the same amount of use.

What About CBD Vapes?

CBD vapes have become enormously popular, and people often assume that because CBD is legal and non-intoxicating, it won’t show up on any drug test. That’s mostly true for the CBD itself, but there are caveats worth knowing.

CBD is metabolized extensively by liver enzymes into a large family of metabolites. After vaping CBD, the most persistent urinary metabolite is 7-CBD-COOH, which has a half-life of roughly 30 hours via inhaled routes. Following a single 100 mg CBD dose, this metabolite can be excreted over the course of several days.¹⁴ Standard workplace drug panels do not screen for CBD metabolites, so this isn’t a direct testing concern.

The real issue is that many CBD products, particularly full-spectrum ones derived from hemp, contain trace amounts of THC. Vaping these products can produce detectable THC in your blood and urine. When participants vaped CBD-dominant cannabis in a controlled study, blood THC concentrations peaked at about 6 ng/mL on average immediately after use.¹⁵ While those levels dropped below detectable thresholds within a few hours in blood, the urine metabolites could still trigger a positive THC screen. If you use CBD vapes regularly and face THC testing, look for products that are genuinely THC-free (CBD isolate) rather than full-spectrum.

Detection Windows at a Glance

Because different substances, sample types, and usage patterns create such a wide range of detection windows, here’s a practical breakdown:

• Nicotine in blood: Typically undetectable 8-12 hours after the last vaping session.
• Cotinine in blood/urine: 2-4 days for occasional vapers, up to 7-10 days for daily heavy vapers.
• Cotinine in saliva: Similar to blood, roughly 2-4 days for light users.
• Nicotine in hair: Up to 90 days, reflecting long-term exposure history.
• THC in blood: 3-6 hours for infrequent users after a single session, potentially longer for heavy users.
• THC-COOH in urine: 1-3 days for a single use by an occasional user; potentially 30+ days for chronic heavy users.
• THC in saliva: Up to 24-30 hours after a single session.

These ranges are approximate. Your individual clearance depends on the dose you vaped, how often you use, your body composition, your genetics, and your overall health.

Secondhand Vape Exposure and Testing

A common worry is whether being around someone who vapes could cause you to fail a drug test. For nicotine, e-cigarettes do emit some nicotine into the surrounding air. One study measured airborne nicotine from various e-cigarette brands at levels between roughly 0.8 and 6.2 micrograms per cubic meter.¹⁶ These levels are far below what secondhand cigarette smoke produces, but they’re not zero. Research on U.S. adolescents found that those exposed only to secondhand aerosol from e-cigarettes had slightly higher cotinine levels than unexposed teens, though the levels remained very low (around 0.5 ng/mg creatinine on average versus 0.2 for unexposed).¹⁷

In practice, these trace levels fall well below the cutoff thresholds used by standard cotinine tests. You’re extremely unlikely to fail a nicotine screening from secondhand vape exposure alone. For THC, the concern is even more remote because cannabis vape aerosol dissipates quickly and doesn’t deposit meaningful amounts of THC metabolites in bystanders under normal conditions.

When Drug Tests Get It Wrong

Even if you know exactly what you vaped and when, drug tests themselves aren’t perfect. Oral fluid testing devices for THC, the kind used in roadside screenings, have known accuracy problems. An evaluation of two widely used point-of-collection devices found that neither achieved the recommended 80% threshold for sensitivity, specificity, and accuracy. False-positive rates were 5-10%, and false-negative rates ran as high as 16%. Accuracy was worst at the 60-minute mark, when THC concentrations in saliva were hovering right around the 10 ng/mL screening cutoff.¹⁸

A newer wrinkle involves synthetic and semi-synthetic cannabinoids like HHC (hexahydrocannabinol), which have become popular as legal alternatives to THC. These compounds can cross-react with the antibodies used in standard immunoassay drug screens, causing false positives for THC. One analysis documented false-positive rates jumping from under 2% to over 10% as HHC products became more common in the market.¹⁹ If you use HHC vapes and test positive for THC, a confirmatory test using mass spectrometry can distinguish between the two, but the initial screen won’t.

Nicotine in Breast Milk

For nursing parents who vape, the clearance question takes on additional weight. Nicotine transfers readily into breast milk and peaks there about 30 minutes after use. One case study found that nicotine disappeared from breast milk by about three hours, but cotinine persisted in the milk for up to 72 hours.²⁰ The relative infant dose of cotinine through breast milk was substantial. While this data comes from cigarette smoking rather than vaping specifically, the pharmacokinetics of nicotine are similar regardless of the delivery method, so the transfer dynamics into breast milk would be comparable. If you vape and breastfeed, timing your sessions to maximize the gap before nursing can reduce infant exposure, but cotinine will linger in the milk well beyond the point where you’ve stopped feeling any effects.

Zero-Nicotine Vapes and What They Leave Behind

Some people assume that vaping a zero-nicotine e-liquid means nothing detectable enters their body. In terms of nicotine and cotinine testing, that’s correct: no nicotine in means no cotinine out. You won’t fail a nicotine test from vaping pure vegetable glycerin and flavoring.

But zero-nicotine vapes aren’t biologically invisible. The aerosol still contains propylene glycol, glycerin, flavoring chemicals, and thermal decomposition products. Identifying validated biomarkers specific to e-cigarette use, as distinct from other exposures, remains an open challenge in the field.²¹ No standard workplace or insurance drug test currently screens for these non-nicotine vaping byproducts, so in a practical testing sense, zero-nicotine vaping is undetectable. Whether that remains true as testing technology evolves is an open question, but for now, the answer is straightforward: if there’s no nicotine or THC in your vape, current standard panels won’t flag it.