Mouth swabs are less invasive, more affordable, and provide faster results than many of the common types of drug tests available, which is why they are becoming one of the most common types of drug tests you’ll encounter. In fact, they are one of the most common drug test mechanisms used by employers, whether for new employment testing or random drug screens and by law enforcement for roadside drug screening. 

Suppose you’ve recently become aware of a pending saliva drug test or feel anxious about your ability to pass a random saliva screening that may arise. In that case, you’ll be happy to know that mouth swab screens are one of the easiest types of drug tests to pass. That’s because they have the smallest detection window compared to other popular drug testing mechanisms. 

If you’re hoping to learn how to pass a mouth swab drug test, whether you’re facing one later today or next week, here’s everything you need to know first:


Table of contents

What is a Mouth Swab Drug Screen? And How it Works

A mouth swab drug screen is a non-invasive type of drug screen that’s used to detect the presence of certain substances in your saliva. The test is administered by swabbing the inside of your cheek or the glands under your tongue with a long, sponge-like swab. In some cases, you may be asked to do the swab yourself. 

Depending on the type of saliva test used, the results may be instant. If they need to be processed in a lab (which is usually true for tests with a more complex testing panel), they may take as long as 24 hours to process. The person administering the test will let you know when and how you’ll receive the results.

Typically, oral swab tests look for the metabolites of the most commonly used recreational substances, which makes them a good option for pre-employment screening or roadside drug tests. 

What does a Mouth Swab Drug Screen Test For?

Although mouth swab tests have a smaller detection period than other types of drug tests, they still can be used to test for a broad range of substances. Some are substance-specific, while others come in the form of a multi-panel drug test, meaning they test for any combination of substances. 

Some of the substances that a saliva test can detect include:

  • stimulants
  • amphetamines
  • barbiturates
  • benzodiazepines
  • opioids
  • cannabis (THC)
  • phencyclidine (PCP)
  • alcohol

How to Prepare For a Saliva Drug Test

If you’re expecting a drug test, you may be advised not to eat or drink at least 30 minutes before the exam. This is important since anything you’ve recently consumed can throw off the results, and some foods can even trigger a false-positive result (more on that below!).

In general, though, saliva tests are low-prep unless you need to take special precautions to help clear your saliva of unwanted substances. In the case that you plan to use an adulterant to help pass the mouth swab test, you may need to do a little pre-planning (and use a little discretion) to help things go smoothly.

Here’s what to consider:

Morning of Drug Test To Do’s

Things to Do Before a Drug Test

Here are some steps to take the morning of your drug test to help ensure a passing result:

Brush and rinse

Brush your teeth and rinse with non-alcoholic mouthwash as normal. This can help remove some lingering unwanted substances and will just ensure a generally clean mouth before your test. 

Drink plenty of water

Avoid dehydration, which can lower your saliva production before the test. 

Try chewing gum or sour candy

Chewing gum or eating a sour, tangy candy can help to increase the production of oral fluids to dilute the saliva collected for the test. 

Grab your necessities

Pack any supplies you may need while waiting for your test, like the Toxin Rid Detox Mouthwash, or any beverage you want to have on hand before the test.

Let’s talk more specifically about a common concern–clearing THC from your system before a saliva test:

How To Clear Weed from Your Saliva

A mouth swab is one of the easiest drug tests to pass, especially on short notice — some mouth swab tests don’t even test for THC! But, don’t ask your administrator what the specific mouth swab drug test you’re taking takes into consideration. That would seem a little suspicious, no?

In general, the saliva test detection window for THC metabolites is a few days for casual weed consumers, and up to a week for a chronic THC consumer. Since the window of detection for mouth swab tests is relatively short, the best idea is to simply hold off on smoking for a few days leading up to the test, especially if you used cannabis only moderately before. 

Edibles reduce the risk of detection a little bit compared to smoking marijuana, but it’s better to just abstain for a couple of days rather than gambling with your results. You may also consider an organic, non-GMO  hemp flower strain to hold you over for a while. 

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.

How to Pass a Mouth Swab Drug Test With 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 better understand how to pass a mouth swab drug test with no notice 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 can 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.

How to Pass A Mouth Swab Drug Test With A Few Hours Notice

What to do before drug test

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. Here’s what you should do:

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 binds to fat, so eating something with high-fat content can help remove lingering THC from your mouth quickly and effectively.

But what do you do if you have no notice at all about an impending saliva drug test? No worries, you still have options:

How to Pass A Drug Test in 24 hours

Okay, so let’s say you have a little more notice–at least 24 hours before your impending mouth swab drug test. In this case, your chances of seamlessly passing the mouth swab test are even higher. 

Beat a Saliva Drug Screen In 24 Hours

If you’re quickly coming up on a drug test in the next day or two, here’s what you should do:

Abstain from Consumption

Abstention for a day or two clears THC from saliva naturally and easily (provided you brush your teeth like normal!). 

Consume Fatty Foods

You can accelerate the THC removal process by consuming plenty of high-fat foods. THC is lipid-soluble, meaning it binds to fat molecules so fatty foods can help make THC make a quicker exit from your mouth.

Brush and Brush Again

What to do before a drug test

You’ll want to combine good oral hygiene with vigorous mouthwashes (alcohol binds to THC as well, but be careful not to use an alcohol-based mouthwash right before the test!). To make sure you pass on short notice,  use this detox mouthwash a few minutes before your mouth swab drug test for an extra layer of protection; it cleanses any lingering undesirable chemicals in time for a short-notice mouth swab.

Does vinegar clean your system in 24 hours?

There are some claims circulating that you can use apple cider vinegar to clear your system quickly before a drug test. In truth, there isn’t much explanation to help back this up. Some people theorize that apple cider vinegar (ACV) creates an acidic environment that helps the body break down and remove the THC metabolite material more quickly. 

Usually, though, this method is used in an attempt to pass a urine test more quickly. Still, there may be some truth to vinegar’s ability to alter the mouth’s pH in a way that throws off the test. We still recommend the methods outlined above, but it can’t hurt to try swishing with ACV as a last-ditch security measure. 

Foods to Avoid Before a Drug Test

Because a swab test takes a sample of saliva, the foods you eat directly before the test can affect the outcome. This is something important to keep in mind before your saliva test, and you should pay close attention to what you eat in the hours prior to the test. 

Can you eat before a drug test?

Yes, you can typically eat before a drug test without worry. In fact, eating some fatty foods may be beneficial if you’re hoping to remove any leftover THC metabolites from your mouth prior to a saliva test. This is because THC is fat-soluble, so the fat may help to break it down and pass it along more quickly. 

Although most foods are harmless in terms of how they will affect your drug test results, some foods can actually cause a false positive. Let’s discuss:

What not to eat before a drug test

What not to eat before a drug test

Some foods can potentially interfere with a mouth swab test in one way or another. The risk is low for most foods, but some foods you may want to avoid include:

  • Poppy Seeds: Poppy seeds come from the Papaver somniferum plant, also known as the opium poppy, the plant material used to make heroin. The seeds are harmless and won’t cause any psychotropic effects, but they may have just enough of the active compounds codeine and morphine to spike a false positive drug test. 
  • Pizza and yeasty bread: According to the manufacturers of a popular breathalyzer, the yeast in pizza and similar breads can ferment in the mouth and create alcohol, which can potentially trigger a false positive.
  • Durian: Although there’s plenty of argument on whether durian is an edible delicacy or just pungent waste, there’s no argument on whether the fruit can interfere with drug test results. Durian can leave behind a decent amount of “mouth alcohol” shortly after consumption, which can trigger a false positive saliva test result. 
  • Hemp seeds: Although hemp seeds contain only trace amounts of THC (even less than the 0.3% allowed in raw hemp material), there can possibly be just enough THC left around if you’ve just munched on a handful, so it’s best to avoid them prior to the test.
  • Tonic Water: This fizzy water contains quinine, a compound that is also used to cut some illicit drugs and may provide results similar to that of a drug user. 

How far back will a mouth swab drug test go?

We’ve mentioned that mouth swab tests have the shortest detection window of all common drug tests, but the amount of time that a swab test can actually detect a substance varies. The following are estimates based on mild to moderate use, and chronic use of some substances (like cannabis) can result in a longer detection window.

  • Cannabis (THC): 12-24 hours
  • Nicotine: up to 4 days
  • Alcohol: up to 24 hours
  • Opiates: up to 5 days
  • Amphetamines and Methamphetamines: up to 3 days
  • Phencyclidine (PCP): up to 3 days
  • Heroin: 24-48 hours
  • Methadone: up to 10 days
  • Morphine: 24-48 hours
  • Barbiturates: 2-3 days
  • Benzodiazepines: up to 3 days

Best Products to Pass a Mouth Swab Drug Test

There are quite a few “miracle products” on the market that claim to help you pass a drug test in as little as one hour. Many of these drug test detox kits focus on urine tests and hair tests, however, since these two types of tests are more difficult to trick.

When you’re looking for the best product to help you pass a mouth swab drug test, you’ll want to look specifically for oral drug test kits. Some products, like specially formulated mouth wash formulas, are designed to help remove detectable drug toxins from your saliva before the test. 

We recommend the Toxin Rid Rescue Wash Mouthwash from Test Clear. Test Clear is a leading distributor in drug test detox kits, and the Toxin Rid Rescue Wash is a simple solution for clearing away unwanted substances just before an oral drug test.

The small 1-ounce bottle is discreet and easy to use. You just swish ⅓ of the bottle at a time and spit it out in the minutes before your oral swab test. For extra measure, just follow up with a few of your favorite breath mints. 

Don’t wait until it’s too late to buy! We recommend keeping a bottle on hand, in your car or day bag for unexpected roadside drug tests or random oral swab tests that may arise. 

Frequently Asked Questions

How Long Does Weed Stay In Your System?

The amount of time that weed is detectable in your system ranges from 1 to 90 days and depends on the detection method used. Saliva tests have a much smaller detection window for THC than other tests, like urine tests or hair tests. If you’re a daily smoker, marijuana will most likely stay in your saliva for only 1-7 days.

How Accurate is a Mouth Swab Drug Test?

In general, mouth swab drug tests are thought to be accurate about 98% of the time, but certain things can affect accuracy, like the type of test used, any adulterants consumed, and the drug type being detected. 

How to explain failed drug test?

In any case, explaining a failed drug test can be difficult. Some have had success placing the blame on certain foods, like poppy seed bagels, or secondhand smoke consumption. If you’re going to try to displace the blame, make sure the scenario matches the substance you failed for. If you believe the test was truly inaccurate, you can usually ask for a retest the following day. 

Are Mouth Swab Drug Tests and Saliva Drug Tests the Same?

Yes, mouth swab drug tests and saliva drug tests are the exact same test, but they may be called by either name. In some cases, they may also be called an “oral fluid test” or “cotton swab drug test.

Table of Contents