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You nailed the interview, passed the background check, and the last step to securing that job is to pass the drug test. Maybe your heart dropped when you heard your future employer utter those words, but not all is lost just yet. 

If you’re being subjected to a saliva mouth swab test instead of a urine or blood test, you may just be in luck as this is the easiest test to pass. That being said, it's still a drug test, and there are a few things you should know before you take it.

What Is a Mouth Swab Test and How Is It Used?

A mouth swab drug test, sometimes referred to as an oral fluids test or a saliva test, gathers saliva from inside a person’s mouth to test for the presence of drugs. They’re a popular choice because they’re both inexpensive and easy to administer.

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If you know you have a mouth swab test coming up, consider yourself lucky. Of the many drug testing methods your employer could choose, they’ve chosen an easier one to pass than say, a urine or blood test.

The saliva tests screen for various compounds in the body, including THC. Since you’re just collecting a sample from your mouth, the tests rely on what is present in your saliva at the time of the test, unlike others which rely on blood or urine where more compounds are present.

Close up of nurses hands holding buccal cotton swab and test tube ready to collect DNA from the cells. iStock / dusanpetkovic

Before applying for jobs or before your scheduled test, you can buy your own drug test in-order to manage anxiety caused by not knowing if you'll pass or not.

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That way, if you're positive you have time to react or if you're negative you can get a better idea as to what you can expect when you show up to the real deal.

How Long Is THC Detectable in the Mouth?

Mouth swab tests are specifically looking for activated THC, unlike other tests which look for the metabolite THC-COOH. This is mostly good news if you have time to prepare, and very bad news if you just hit the bong before nailing a job interview, only to be offered the job contingent on the results of the drug test they’re handing you right now.

There is not an exact number for how long THC can be detectable in your mouth, though it typically falls between 24 and 72 hours. Some claim to work for up to a week, so if you’re in the business of frequent smoking, you’ll probably want to take a good week off to pass the test naturally. If you don’t smoke that often, taking a three-day tolerance break may be all you need.

Use 24 hours as a bare minimum for the amount of time you’ll need to pass the test.

How to Pass a Mouth Swab Test With Time To Prepare

If a mouth swab test is coming up in your future, the best thing you can do is be prepared. If a surprise swab is sprung on you, you’re going to have to rely on the universe to have your back or just accept a failed test if it’s handed on the spot.

Stop Smoking

I know, it’s not the most helpful advice but it works the best. If you have a week to prepare for your swab test, you should spend that week not smoking to ensure you will pass.

Even if you only have a day to prepare, stop smoking. It’s common to pass the test within 24 hours of smoking if you come in with a clean mouth and a clear mind.

Assess your own consumption with how much preparation you’ll need. If you don’t smoke much, you probably don’t need much time for all the THC to clear your mouth. If you do smoke often, you should give yourself a couple of extra days to guarantee you’re clean.

How To Pass a Mouth Swab Test With Little Notice

If you have to take a mouth swab test and it’s been under 24 hours since you last took a puff, you’re not completely out of luck. You may be able to clear the THC from your mouth in time to pass with a few tricks.

Clean Your Mouth Extra Thoroughly

Girl doing her mouth hygiene in the morning. iStock / Capuski

The mouth swab test is looking for THC in the mouth, so naturally cleaning your mouth well will have some benefits.

There are also a few THC mouthwashes on the market you can buy.

Good oral hygiene should be practiced regularly, but this is an especially important time to brush, floss, and rinse those pearly whites.

The more you brush your mouth and rinse, the more you’re going to flush the THC out from your mouth. It’s a good idea to pay extra attention to oral hygiene in the days leading up to the test, but even with little notice, this is a good start.

Eat Fatty Foods

If you have time to run and get yourself the greasiest and fattiest meal you can find, you may be able to take some of the THC down with your food. Since THC binds to fat, any floating around in your mouth may make its way down with your burger and fries.

You’ll want to brush your teeth and rinse your mouth after this as well because if you have any bits of fatty food stuck in your teeth, the THC will bond with it. and be detected on the test. 

Alter Your Saliva

You can also rinse your mouth with hydrogen peroxide or mouthwash which will help alter your saliva, but you’ll need to do this soon before you take the test because the effects won’t last much longer than a half an hour.

Hydrogen peroxide is your best bet in a pinch, but if a drug test is sprung upon you last minute, you may not have time to discreetly do this.

If you’re standing in the company bathroom before taking the swab test, desperately seeking mouthwash or hydrogen peroxide with no avail while simultaneously searching Google for help, calm down. Don’t spend forever in the bathroom only to come out already looking guilty.

Swish some water around as if it were mouthwash and spit it out. Do this a bunch. Potentially, you could dilute the THC content in your saliva enough to be undetectable, but this is probably the least fruitful option.

Final Thoughts On Passing A Mouth Swab Test

As with any drug test, the more warning you have, the better. Somewhere between 24 and 72 hours after smoking will probably be safe for you to pass, but it varies person by person and by how much they consume.

As soon as you find out you have a swab test coming up, stop smoking and take extra care of your oral hygiene.

These tips are not fool-proof ways to pass a swab test. The only way to guarantee you won’t fail is to not consume cannabis. If you’ve already broken that rule, these tips may help you improve your chances of passing.