A mouth swab test for drugs is only good for one thing – testing for recent use of THC. If you smoked weed yesterday or ate an edible last month, an oral swab drug test won’t turn up positive. But, if you dabbled in a little marijuana over your lunch break, and your employer decided to implement a mid-afternoon drug test, you might be in trouble. How to pass a mouth swab drug test is all about how to cleanse your oral cavity from all traces of THC.

The important thing to remember about mouth swab drug tests is they can only confirm drug use within a short timeframe. Even for heavy smokers, there is a relatively low risk of testing positive for THC if they merely abstain from smoking for 24 hours. Why? It all comes down to science.

The Science Behind an Oral Swab Drug Test

No matter what drug test you are subjected to, they all work under the same premise. All tests collect organic material (urine, blood, hair, or saliva) and confirm whether or not the specified compound (THC, cocaine, heroin, or other metabolites) has surpassed the test limit. For example, a test may confirm if there is more than 50 ng/ml of THC in the tested sample. More? That qualifies a positive test.

In most cases, the drug test doesn’t actually test for the drug itself. Instead, the test looks for something called metabolites. These compounds are produced by our bodies once the original substance metabolizes in the liver.

If you smoke marijuana, it passes through the lungs and into the bloodstream. If you eat a weed-packed edible, it takes longer to reach the bloodstream by way of the digestive tract. Both bloodstream entry points, eventually lead to the liver. The liver cleans the blood, and through this process metabolizes various compounds, like THC.

The most common cannabinoids in marijuana, THC, turns into THC-COOH. Heroin turns into 6-MAM Morphine. Alcohol metabolizes into acetaldehyde. Urine tests, blood tests, and even hair tests all check for the THC-COOH metabolite, instead of the illicit drug itself. Oral swabs stand out because they test for the initial drug or the THC.

How to Pass A Mouth Swab Drug Test?

Facing any drug test is stressful enough, but facing an oral swab is probably the most stressful. Employers rely on saliva tests because they are cheap and because they test for only most recent drug use. It makes it all the more difficult for employees to prepare beforehand.

With that in mind, there are a few options out there which might improve your chances of passing. Try one, or try all, whatever works for your situation and before the big test.

Abstain from Drugs – All of Them

At the very least you need to stop taking any and all drugs as soon as you find out about the test. For most people, it will take eight hours for the THC to absorb into the bloodstream. For heavy users, it may be up to 72 hours.

Practice Good Oral Hygiene

Whether or not you are facing an upcoming drug test, you should always listen to your dentist. What’s good for your teeth might also flush out any lingering THC molecules. Brush your teeth more than usual, up to four times a day before a drug test. Pay particular attention to the areas you normally overlook. This means, your gums, tongue, and cheeks. Another good area to focus on is the crevices between your teeth. Brush carefully, and mindfully.

Stop Smoking Cigarettes

Do you smoke cigarettes? Its recommended to also abstain from cigarettes before a drug test. Smoking anything opens up the cells and taste buds in your mouth, releasing more saliva. This could potentially release more THC. The last thing you need before a drug test is more THC laden saliva sloshing around your mouth. At the very least stop smoking for 48 hours. Once you pass your drug test, you can than practice rolling the perfect spliff.

The Poppy Seed Effect

Because the standard drug test is a five-prong approach, meaning, it tests for five different illicit substances, it goes without saying to stop doing all drugs. But just like the infamous Seinfeld episode, where Elaine tests positive for opium, you also should stay away from poppy seed bagels. Poppy seeds come from the same poppy as opium, be warned!

Eat Fatty Foods

The THC compound is a fat-soluble substance, absorbed quickly into lipids but not into water. Consuming high-fat meals before a drug test can boost the THC absorption rate, transforming THC into THC-COOH. This may get you off the hook for an oral swab drug test. However, it will increase the amounts of THC-COOH stored in your fat cells.

Icy Cold Hydration

Beyond staying hydrated, some people recommend chewing as much ice as possible before a saliva test. This keeps you hydrated overall, and dilutes the THC content of your saliva to hopefully below the testable levels.

How to Pass a Mouth Swab Drug Test with Peroxide – Last Ditch Efforts

There are suggestions online about using chemicals to pass an oral swab drug test. You aren’t alone if you’re cringing at the idea. Learning how to pass a drug test with peroxide is not at the top of everyone’s list. But, it is still one last-ditch option, open to the most desperate pot smokers facing a surprise drug test.

Importantly, using chemicals to cleanse out your mouth shouldn’t be the first option you attempt. Using peroxide or other harsh substances falls squarely under the “Try at your own risk” category. These chemicals come with warning labels for a reason.

If hydrogen peroxide is a bit too toxic for your personal tastes, there are much more natural options to try. Some recommend swishing with lemon water two to three times a day until the drug test. Others suggest white vinegar, used in the same way.

If you do try the peroxide method, be sure to dilute it before cleansing. Never swallow the mixture, and carefully rinse out your mouth following each gargle.

How to Pass a Mouth Swab Test: Reports from Our Followers

It’s hard to find any reports online about people who have successfully passed oral drug tests. Most testimonials are all about using detox kits to cleanse for an upcoming urine or blood test. Unfortunately, oral swabs are on the rise, because they are cheap and easy to perform. More and more people, including some of our followers, have faced one during interview or on the job. Here’s what they describe in their own words:


“I know there are a lot of posts on passing/failing a saliva drug test, but I wanted to report on my specific case. Today I took a drug test for a job. It was a saliva drug test (Oral Eze). My last bowl was four days ago. I’ve been smoking consistently for the last two years usually a bowl a night but lately its been a few bowls a night. I did a lot of peroxide swishing/Listerine/brushing for a few days last week, but I figured if I am abstaining I should be okay. This proved correct, as I got my test results back and I passed.”

Tim Penner

“Hey all, I decided to write a little experience comment, because everywhere I looked online I couldn’t find a solid answer to someone passing a saliva drug test.
I’ve read multiple pages claim 24-72 hours abstinence from weed will be enough.
I’m pumped because I just passed my drug test (for a job I really wanted) and I last puffed the golden stuff 23 hours ago.
I smoke regularly and usually concentrate, so needless to say I was worried. The key is brushing the teeth. Do it like you haven’t visited the dentist in years and are about visit again. I brushed everything inside my mouth, gums, tongue, even the cheeks. Every single millimeter inside, better safe than sorry. I brushed 3 times the day before and 4 times the day of.
Also, drink copious amounts of water, use mouthwash every time you brush, and I even went a little extra with gargling vinegar and water right before heading out to test.
Passed the saliva drug test no problem, good luck to everyone!”

More Information on Saliva Tests

If you are still nervous about an upcoming saliva test, beyond the basic recommendations on how to pass a mouth swab drug test, we’ve got you covered. There is much more to explore on How Long Does THC Stay in Your Saliva, including what lifestyle changes you can make to improve THC absorption. Knowing the full facts behind how a saliva test works can help you prepare.