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How To Pass A Swab Test With Listerine Strips

In this article, we’ll explain the theory of how to pass a swab test with Listerine strips, but we urge you to think carefully about the consequences of failing the test.

Can you really pass a swab test with Listerine strips or is this just another far-fetched falsehood on the internet?

Many people claim that they have successfully passed a saliva test by using Listerine mouthwash or Listerine strips. But is this true, and do you want to take the risk that it isn’t?

Failing a drug test can have life-changing repercussions. If you’re applying for a really great new job, the employer could reject your application after a failed drug test, and if you’re already employed, you could lose the job that pays your bills.

Trying to fool a drug test is not something to be taken lightly, and if you have enough advance warning of the test, your best course of action is to avoid taking any drugs during that period. This is the only way you’ll know for certain that you will pass your swab test.

With that said, let’s take a look at the claims for how to pass a swab test with Listerine strips.

How To Pass A Swab Test With Listerine Strips

How To Pass A Swab Test With Listerine Strips

Using Listerine strips to pass a swab test is unlikely to work unless you have an advance warning of the test.

You shouldn’t rely on this method to help you beat a random drug test at work, but if you’re applying for a job or a promotion and you need to pass a drug test, then, as the theory goes, Listerine mouthwash and Listerine strips can both be used to improve your chances of passing the test.

You should know that drug screen tests for several substances and Listerine strips have only been reported to help with avoiding marijuana detection.

The reason that Listerine strips work according to the most popular theory is that they absorb the remaining THC metabolites from your saliva. This claim has no scientific backing, by the way.

Related Resources: How To Pass A Drug Test With Certo

Steps To Take

The first thing you should do is avoid using marijuana in any form for at least 48 hours before your test is scheduled.

Next, you need to increase saliva production by eating plenty of foods with high water content. Good choices are foods like fruits and vegetables and spicy foods.

The goal is to keep your mouth as moist as possible, so your saliva can continually cleanse the THC residue from your mouth. Avoid foods like crackers and chips that give you a dry mouth.

Eating fatty foods can be a good idea too. THC metabolites attach to fat molecules, so by eating fatty foods, you can remove more of the marijuana residue from your mouth.

The next part of the process is brushing your teeth and mouth. You need to brush your teeth thoroughly, and then you should brush your gums, your tongue, and inside your cheeks. Brush for at least 5 – 10 minutes, three times a day.

You may want to use a softer toothbrush than you normally use. If you use a brush with firm bristles, the extra brushing of your gums and cheeks will make your mouth sore and you may not be able to brush for as long as you need to.

Each time, after you finish brushing, rinse your mouth thoroughly with Listerine. Really swish the mouthwash around before you spit it out, even if it starts to sting.

On the day of the test, give your teeth and mouth a much longer cleaning session. Aim to brush for 20 – 30 minutes. Use plenty of toothpaste and spit and rinse every couple of minutes.

After you have thoroughly brushed your teeth and mouth, and rinsed your mouth with Listerine, place two Listerine strips inside your cheeks and another under your tongue. Take a bottle of water with you on your journey to the test site.

As the strips dissolve, rinse your mouth with water, then place fresh strips inside your mouth.

When you reach the test site, continue swishing your mouth with water from your water bottle. Apply fresh strips, replacing them as they dissolve while you wait to be called in.

Once you’re in the test room, the technician will ask you to avoid eating or drinking anything for 10 minutes. This is so you can’t put anything in your mouth at the last minute that could interfere with the test result.

During this time, you should try to generate as much saliva as you can to clean as many of the remaining traces of THC metabolite from your mouth.

Now the technician will use a cotton swab or sponge stick to swab inside your cheek or under your tongue.

Your saliva sample may be tested on the spot, in which case you’ll have your result in a few minutes. If they don’t carry out immediate testing, they will send your sample to a lab for analysis.

Lab results usually come back in 24-hours, but if the lab is very busy, you may need to wait as long as a week or more to get your result.

Related Guide: Can I Pass A Drug Test With Hand Sanitizer?

Which Drugs Can A Swab Test Detect?

Which Drugs Can A Swab Test Detect?

Your saliva sample will most commonly be analyzed using a 5-panel drug test.

The 5-panel test will detect:

  • Opiates
  • Cocaine
  • Marijuana
  • Amphetamines and Methamphetamine
  • Phencyclidine (PCP) also called Angel Dust

These drugs remain detectable in your saliva for varying periods of time.

Opiates including heroin, morphine, and codeine can be detected in your saliva up to 36 hours after use.

Cocaine can be detected using a saliva test for up to 48 hours after use.

Marijuana metabolites can ordinarily be picked up with a saliva test for between 12 to 48 hours after use, but metabolites can be detected for longer if you’re a heavy user or have a high body fat percentage.

THC metabolites will also remain in your body for longer if you smoke strong strains of marijuana. Abstain for longer if these exceptions are true for you.

Amphetamines and methamphetamine can be picked up by a saliva test up to 48 hours after use.

Phencyclidine, PCP, or Angel Dust will show on a saliva test for up to 48 hours.

One thing that everyone taking a drug test should be aware of is that poppy seeds can give a false-positive result for morphine. So if you’ve got a drug test coming up, avoid eating poppy seed bagels or any other foods containing poppy seeds.

Is There Any Proof At All That This Method Can Work?

Unfortunately, the only proof is anecdotal evidence from marijuana users who have passed their drug test after using the Listerine strip method.

Because people have different drug usage patterns, it’s unwise to base your decision on the experiences of others.

The experience of someone who smoked a couple of joints at the weekend and then used Listerine strips to pass a drug test 4 days later, doesn’t give you any useful information about your chances if you smoke daily and have to take a test in 2 days.

Test The Process Yourself To Make Sure That It Works

Test The Process Yourself To Make Sure That It Works

The only way to know if this process will work well enough to beat a drug test is to take a drug test yourself. This way you get a real-world result instead of crossing your fingers and hoping for the best.

There are lots of times when turning to the Internet can produce a definite answer to a question and give you a guaranteed process to follow, but this isn’t one of them.

You can easily find 5-panel drug tests to buy from pharmacies or from online stores, including Amazon.

On the day of your test, follow the instructions provided with your at-home test and swab your mouth. You’ll see your result in a few minutes. If it’s clear, you’re clear. But you may want to use a few Listerine strips just to be sure.

If your test gives you a positive result, go and scrub your teeth, tongue, gums and inner cheeks again, then rinse your mouth with more Listerine.

Dissolve a couple of Listerine strips against your cheeks, wait 10 minutes, then retest yourself.

If you still get a positive result, then it’s very likely that your actual test will also return a positive result for marijuana.

What should you do if this happens? If it’s possible for you to reschedule the drug test, then it would make sense to take your test a day or two later so you can definitely pass.


The only guaranteed way to pass a swab test with Listerine strips is to abstain from drugs in the period before you take the test.

While people do report passing a drug test with Listerine strips, it’s unwise to base important decisions on what amounts to hearsay.

In any case, Listerine is only claimed to work on the marijuana part of the drug screen, so if you take Opiates, Cocaine, Amphetamines, or PCP, the Listerine method cannot help you at all.

And remember, because the Listerine strip method needs time to work, you can’t rely on Listerine strips to help you beat a random drug test at work.

Read Also: List of Companies That Don’t Drug Test