Medically Reviewed by
Jason Crawford

Article Last Updated on January 8, 2023

Drug screening for cannabis in the workplace is slowly becoming the norm, despite the marijuana legalization happening state-wise. Still, employers feel the need to check their employees for drug use, especially in job sectors that require operating with heavy machinery, medicine, handling sensitive information, working with people, etc. – virtually any type of job that requires a high level of responsibility.

Even though the urine drug test has been the standard drug screening method for years, lately, the mouth swab test is also being used because it’s cheaper and simpler to do. Drug testing is never fun for a weed enthusiast, but when your boss requires it, you gotta do what you gotta do.

The next sections will cover some tips about what you can do to pass a swab test safely. Keep in mind that this article is purely for educational purposes only.

What You Should Know About Cannabis Drug Testing

Drug tests were designed to look for the presence of different types of drugs and alcohol, including opiates, barbiturates, amphetamines, methamphetamines, benzodiazepines, and cannabis, among others. 

Currently, there are four types of drug testing methods being used to detect marijuana use, and they are:

  • The saliva drug test or oral drug test – one of the least invasive and done by taking a mouth swab;
  • The blood test – the most invasive one and the least commonly used in the workplace;
  • The urine test – non-invasive and the most commonly used in the workplace, and also quite accurate;
  • The hair follicle test – the most accurate one and with the longest detection time of up to 90 days, very rarely used in the workplace.

Each of these types of drug tests has its own detection window which refers to the length of time during which the presence of the drug can be detected. 

Drug tests detect substances at a certain cut-off level, meaning the level at which the substance becomes detectable. Any concentrations at or above this level will produce a positive result.

THC and Its Metabolites

If you didn’t know, when you consume marijuana, its cannabinoids get metabolized in the liver and they get turned into byproducts called metabolites. These metabolites are fat-soluble, meaning that they attach themselves to the fat cells in your body and then get slowly eliminated from there. 

The most stubborn metabolite of them all is the main THC metabolite called THC-COOH, which is, coincidentally, the target of some drug tests. The hair test and the urine test screen for the amount of THC metabolites present in your body because they stay there for a while.

What Type of Drug Test Is the Mouth Swab Drug Test?

The oral fluid test isn’t as commonly used as the urine drug test, but it’s still used in the workplace, even more commonly so in the last couple of years because it’s more affordable than the urine test and it’s much simpler to do.

The oral fluid test has a short detection window of up to 72 hours since you last consumed weed, though this could extend to a few days, depending on how frequent of a user you are.

Unlike the urine and the hair tests, the mouth swab drug test doesn’t detect THC metabolites, but THC itself because when you consume marijuana, THC lingers in the salivary glands before being absorbed and metabolized. This is an advantage, in a way, because it’ll clear up faster.

Tips on How to Pass the Saliva Drug Test

Let’s see how you can prepare and successfully pass the saliva drug test. Please note that the section below is for educational purposes only as we are not recommending cheating on drug tests.

Abstain From Smoking Weed

The most obvious thing you can do before an oral swab test is to abstain from consuming weed and give your oral cavity time to clean itself. The more time you abstain from using weed before the test, the better, especially if you’re a daily user.

Drink Lots of Liquids

Drinking a lot of liquids also helps. Sure, water won’t help you detox from weed in the traditional sense, but hydration will help with saliva production, and new saliva makes THC harder to detect. You can drink water, juices, or tea, as long as it’s not caffeinated beverages that will dehydrate you.

Use Chewing Gum

Many people underestimate chewing gum, but this stuff can help. It regulates the acidity in the mouth and stimulates your salivary glands, which help with the detox process by diluting the THC that’s present in your saliva. If you want to take things to the next level, you can try using the Oral Clear Gum, which is a chewing gum that neutralizes saliva.

Practice Good Oral Hygiene

Maintaining good oral hygiene is essential even if you’re not preparing for a saliva drug test, but you should pay even more attention to it when you are. Don’t skip flossing and brushing your teeth 2-3 times a day, and definitely don’t skip the tongue scraper. 

Also, clean the inside of your cheeks as well, because mouth swab tests take a sample from those areas. You want to increase your chances of passing the test by giving your oral cavity the space to get rid of the THC. This is especially important if you’re a frequent user because you’ll probably have a bigger THC buildup.

Chew Sour Candies

Preparing for a mouth swab drug test is a good excuse to eat a lot of sour candies. Or, if you don’t like them, maybe now you’ll learn to appreciate their mouth-salivating properties. Sour candies are champions at excess saliva production, plus they taste delicious. The sour-and-sugary combo will not only stimulate saliva production, but it’ll make THC harder to detect, making these types of candies worth a try.

Eat More Fatty Foods

As we said, cannabinoids are fat-soluble, so they attach to lipids faster than lightning. Therefore, eating some fatty foods could help to draw THC out of the saliva and get rid of it faster. So, choose your favorite fatty meal and treat yourself to a delicious dinner prior to the test.

Rinse Your Mouth

Sometimes you’ll be told days ahead that you have a drug test coming up, but other times, your employer may spring it on you and you’ll only have a couple of hours to prepare. If you’ve smoked in the previous 24 hours, this might freak you out, but you shouldn’t panic because there is a solution. 

According to the anecdotal testimonials of many fellow weed users, rinsing your mouth is probably the most effective short-term solution to passing a saliva drug test, you just need to use something other than water.

  • Use a specialized detox mouthwash. There are specialized detox mouthwashes, such as The Detoxifying Mouthwash by Stinger, that are developed specifically for detoxing your oral cavity. They’re alcohol-free and their effects last for about an hour – perfect for short-term notices.
  • Rinse with Listerine. Listerine is one of the most effective and most commonly used mouthwashes and it can help you pass a saliva test. However, make sure it’s an alcohol-free one if you want to avoid a false-positive result for alcohol.
  • Try swishing with a maximum of 3% hydrogen peroxide. Hydrogen peroxide is an effective adulterant that will dilute your saliva in no time. Just swish it around your mouth as you would with regular mouthwash and spit it in the sink. Do not swallow it under any circumstance.

If you have around 24 hours to the test, make sure to use your chosen rinsing solution religiously and thoroughly clean your oral cavity. For the best results, fellow users recommend rinsing your mouth as close to the test as possible.

Can CBD Oil Influence the Oral Swab Test Results?

Drug tests don’t normally screen for CBD because CBD is a non-psychoactive cannabinoid, so the chances of getting a positive result are slim. Most CBD oil products on the market today legally contain no more than 0.3% THC, which is a very small amount and can’t really be detected. However, you should be careful with smoking high-CBD strains as they tend to contain more significant amounts of THC.

The Takeaway

No one likes to test for drugs, but when your job depends on it, you have to. The mouth swab test is one of the simplest drug tests and with the shortest detection window because it screens for THC itself, rather than its metabolites. We don’t recommend cheating on drug tests, we simply covered some of the ways to pass a swab test purely for informational purposes only.

A passionate advocate for the benefits of cannabis. Fraser Horton, who has a background in botany and a strong love of nature, has spent years researching how cannabis affects the body and mind. He established Leaf Nation in 2020, where he has devoted himself to educating people about the legalisation of marijuana and its safe and responsible use. Fraser is committed to highlighting cannabis’ potential for improving wellness and working to dispel the stigma associated with its use.


The information presented on this page is provided as a public service to aid in education and is derived from sources believed to be reliable. Readers are responsible for making their own assessment of the topics discussed here. In no event shall Leaf Nation be held reliable for any injury, loss or damage that could happen if using or abusing drugs.