While cannabis is legal in an increasing number of states, that doesn’t mean employers aren’t still testing for it. If anything, legalization has renewed interest in drug testing (largely to do with the alleged increase in people driving under the influence), particularly using mouth swabs. Mouth swabs are some of the most commonly used drug tests, and it benefits everyone to know how to pass one.

So how do mouth swabs differ from other types of drug testing, and how can you pass one easily? Here, we’ll discuss the science of mouth swabs, what they test for, how long THC stays in your saliva, and how you can accelerate the process of clearing it out to pass a drug screen.

What Do Mouth Swabs Test For?

Saliva tests differ from https://keytocannabis.com/products/testclear-at-home-thc-urine-drug-test-product-review in the chemical compound they test for. Urinalysis screens for both THC and its primary metabolite, THC-COOH. Saliva tests, on the other hand, test only for activated THC, or delta-9 THC, the stuff that ends up on the inside of your mouth after taking a bong rip, a puff off a vape, or a bite of an edible.

In a way, this is good news: it means that, since THC doesn’t stick around long in your saliva, the ability of the test to detect cannabis consumption is pretty short-lived. It also means that the test won’t pick up lingering metabolites in your system. However, it still tests for the psychoactive, and thus illicit, delta-9 THC that lingers in your spit in the period following consumption.

What Type of Employers Use Mouth Swab Drug Tests?

While urine tests are an employers favorite type of drug test (being used over 75% of the time for drug screenings) the reality is, there are still many businesses that use the good old saliva drug test to get the job done. Saliva drug tests are easier to administer than most other drug tests, and because of this, employers will regularly save money by completing these in house.

Because of these reasons, smaller businesses and those that give tests on the fly are typically the ones that use mouth swab drug tests thanks to their simplicity.

We typically see the following verticals being the ones that are tested most for THC:

  • Union Workers
  • Transportation
  • Energy
  • Construction
  • Federal Employees

Generally, drug testing is a common practice among those who handle jobs that deal with physical labor, protection, health, property, and safety.

When it comes down to it, even using 100% legal marijuana can prevent you from securing or keeping your job. You always want to be prepared and aware of what type of drug test your employer plans on giving you if any.

When do Employers Use Mouth Swab Drug Tests?

Since the mouth swab drug test is so simple to use it’s prone to be administered before employment, random screenings, or after a work-related incident.

  • Before Employment – It’s a common policy for employers to screen potential employees and applicants even before they are guaranteed employment. The reason that employers attempt to do this is that you are at your most vulnerable — you can’t appeal the drug test, you’re not apart of a union yet, you have no time off to avoid the situation. It’s the perfect time for an employer to undergo a drug test.
  • Random Screenings – Randomized drug tests are typically given at regular intervals and without notice by employers in labor-intensive jobs. Be aware, that in some states, there are laws in place prohibiting your workplace from administering a drug test without adequate time. Educate yourself to know your rights! Additionally, if you suspect you’re being ‘picked on’ by your employer for not-so-random drug tests — be sure to also look into your discrimination laws.
  • Post-Work-Related Incident  These drug tests occur after a work incident that has caused damages to property, injuries, or a very ‘near-miss’. Some workplaces have it in place so that if any ‘incident’ occurs, you automatically will have to take a drug test. In other cases, your direct superior will decide after the accident if you will need to take a drug test.

How Long Does THC Stay in My Saliva?

Fortunately for cannabis consumers, THC doesn’t hang out in your saliva for very long, and any THC metabolites on their way out of your system from your salivary glands aren’t going to show up on the test, because the test isn’t looking for them.

Technically, there’s nothing keeping THC in your saliva. It coats the entire surface of your mouth when you smoke or consume it, but it dissipates pretty quickly after that. Even if you, for instance, literally never brush your teeth (gross), THC would only remain detectable in your saliva for a week or less after you last consumed it. For most of us with good dental hygiene, the number is more like a day or two.

This means that, if you know the test is coming up, you can simply abstain from cannabis for a day or two, and perhaps be extra vigilant when you brush your teeth. If you need to speed up the process, however, there are things you can do to accelerate the clearing of THC from your saliva.  Since you can purchase CBD legally online now, you can also try the abundant types of CBD concentrates and isolates out there. Canna Comforts offers organic, non-GMO hemp flower strains that look, smell, feel, and smoke just like their high-THC muses, and lower the risk of failing a drug test.

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How To Clear THC from Your Saliva

Since the window of detection for mouth swab tests is relatively short, it’s a good idea to simply hold off on smoking for a few days leading up to when you suspect the test. Edibles reduce the risk of detection a little bit, but it’s better to just abstain for a couple days rather than take the gamble. You might also consider an organic, non-GMO hemp flower strain or https://keytocannabis.com/products/canna-comforts-cbd-kief-elektra-product-review in the interim. Researchers are working on a test with lower ranges, so it’s a good idea not to put yourself at risk for a nasty surprise!

Sometimes, however, you don’t have an advance warning, requiring you to find a quick solution to help you pass the swab. For these time-sensitive instances (like a police checkpoint or a surprise test at work), there are two reliable ways to pass the test.

Passing A Mouth Swab Drug Test With A Few Hours Notice

As far as surprise drug screens go, the best-case scenario is that you’re going to be tested, say, at work, but you have a few hours before the swab. First, start drinking lots of fluids. Vigorously swish water around in your mouth, and use a non-alcoholic mouthwash if you have some on hand. If you can brush your teeth, absolutely do, and be thorough!

It’s also a very good idea to get a helping or two of some fatty food. Remember, THC is lipid-soluble, meaning it bonds to fat, so eating something with a high-fat content can help remove lingering THC from your mouth quickly and effectively.

Passing a Mouth Swab Drug Test With Little to No Notice

In the worst-case scenario, you get pulled over and don’t have a moment to spare. Don’t freak out just yet: you’ll be prepared after reading this guide. It’s time for some adulteration!

You might have heard of the adulteration method if you’ve been researching how to pass a drug test: adulterants are chemicals that interfere with a drug test’s ability to read the sample, and there are new and improved ones coming out constantly. This is because there’s an arms race of sorts between drug testing companies and the people trying to beat them: an adulterant works and beats the test, only for a new test to come out that can detect the adulterant’s presence, and the process starts all over again.

For mouth swabs, the general adulterant of choice is hydrogen peroxide. You can swish some vigorously around in your mouth quickly and adulterate your saliva enough to fool the test. This trick only works for a short period of time, so you have to use it just minutes before you’re swabbed. For this reason, it’s not ideal, but it does work in a pinch.

We recommend keeping a bottle of Toxin Rid in the glove box for such instances, as it works quickly and reliably, and certainly tastes better than hydrogen peroxide (ick). Swish with one-third of the bottle at a time, spitting between, and pop in a couple of breath mints for good measure.

Have a full 24 hours to pass your mouth swab drug test? See our blog on how to pass any type of drug test in 24 hours.

A Quick Note About CBD & Drug Testing

If drug testing is a part of the conditions of your employment, you might be concerned about the potential of CBD to cause you to test positive for THC. This isn’t an unfounded concern — however, there isn’t exactly a cut-and-dry way to answer it.

Much of the data we have about CBD is anecdotal, and its potential impact on drug testing is no exception.  There are very few peer-reviewed studies on the subject, and the ones available paint a rather murky picture:  avoiding full-spectrum products containing traces of THC can reduce your risk of a false positive, but that may not eliminate the risk entirely.  A single study (as yet unconfirmed) suggests that even isolate-based products may not be completely risk-free under certain circumstances.

If you are concerned about passing a drug test, you’ll need to consider this potential risk when deciding whether CBD is right for you. To learn more about the science of CBD and drug testing, check out our article for a more thorough discussion of how to minimize your risk of a false positive.


As far as drug screens go, mouth swabs are pretty easy to beat. They only detect THC for a short time and are easy to pass with flying colors if you know a few days in advance. However, if you’re caught by surprise, you still have options! Keep calm and get your mouth clean as quickly as possible, or deploy an emergency method a few minutes before the test. We suggest stocking up with some https://keytocannabis.com/products/toxin-rid-rescue-wash-mouthwash-product-review—use discount code: ‘TestClear10‘ to get 10% off of all TestClear’s detox products sitewide!

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