How to Pass a Mouth Swab Drug Test for Weed

What Is a Mouth Swab Drug Test?

A mouth swab test is a drug test where they take a sample of your saliva and test it for drug residues. They are looking for drug residues which come about through direct oral use of a drug, not residues which have gone into the bloodstream and reappeared in the saliva. So they are looking for drugs taken orally and nasally. This could be smoked marijuana, edible marijuana like marijuana brownies and candies, fentanyl lollipops prescribed or illicit, vaped marijuana, snorted cocaine, smoked methamphetamine and the like. Any of these can show up in saliva. However, the detection period is just 2 to 3 days and often less than that realistically.

How does a mouth swab drug test work?

The initial mouth swab will return results in just minutes. Drug residues will stick to antibodies within the test and reveal with a color pattern if drugs are present at detectable levels. This is called an immunoassay. If drugs are detected, they may confirm the result by sending the sample to a lab to perform gas chromatography / mass spectrometry and verify the result.

These are the cut off limits for many drugs of abuse and medications. If you have used a small amount of a substance greater than 3 days ago, your chances of passing a saliva test are very high even if you do not use a detox method.

What is an Inconclusive Test?

If your saliva is too dilute, you could get an inconclusive result. How might this happen? If you washed your mouth out and failed to salivate sufficiently, this can happen. Or, if you are intentionally holding extra fluid in your mouth in an effort to thwart the drug test. Unless you have been using oral drugs right there on the job, this is likely unnecessary as your chances of passing are already fairly high. Many employers may use a saliva test because they know them to be ineffective unless you are using drugs on the job due to the short detection window. If you are using drugs while at work (unprescribed), most likely you have a problem and you will have to face it sooner or later.

An inconclusive test could mean you may have tried to beat the test, but as of today, there is no way to prove this and anyone claiming they have proof is likely bs-ing you. The vast majority of inconclusive results should be a result of innocently drinking too much water and this is not a crime. However, any potential employer can choose to disqualify an inconclusive result.

Which Employers require passing swabs screens for drugs?

When Do Employers Use Mouth Swab Drug Tests?

  • After an accident

If you are operating heavy machinery, a big truck, a van, or a company car, you may be tested with an oral test to see if you have been under the influence at the time of the accident. Many drugs will show up minutes after use, some will have to reach the bloodstream first, but this test gives the best estimate of on job drug use.

  • You shot someone

If you are a police officer or even a regular citizen and you shoot someone, you may be tested for drug use to see if you were in an altered state at the time of the shooting. This can lead to conviction, but can also aid an insanity defense or an argument of diminished capacity.

  • Before a doctor ordered test or before giving scheduled medications

A doctor or psychiatrist may have you drug tested before administering scheduled medications like benzodiazepines or methadone to make sure you do not have a pre-existing addiction or to avoid drug interactions with medications she intends to prescribe

  • Before a promotion/pay raise

If you are up for a promotion, you may have to have a drug test to get a new title and position

  • Before truck driving school or other Department of Transportation regulated employment

Truck drivers and those getting licenses to operate heavy machinery may be drug tested to assure they are not under the influence of mind altering drugs

  • Pre-employment

This may be the most common reason for a drug test of any kind. However, pre-employment drug tests are usually urine tests, not saliva tests. Saliva tests are used to discover very recent drug use

  • Returning to duty after an accident (military, police)

If you are returning to duty, you may get a drug test. Police, surprisingly, rarely get these in the United States and this is a reason police officers have high levels of drug addiction[1]

  • Suspected drug use

If you are suspected of drug use, on the job, and someone has likely told on you, you may get a saliva drug test

Oral swab drug test thc detection times chart

Saliva drug test detection times thc

Mouth swab drug test detection period chart

Q and A

Q: Why Doesn’t THC Stay In The Salivary System For Very Long?
A: THC itself will show up in the saliva an hour after you ingest an edible, smoke a joint, or vape THC. This is the unmetabolized form of THC.  If you have stopped using the drug, your saliva will likely be clean of this type of residue within 48 hours. However, there are two forms of THC which can be tested for. One is Δ9-THC. This is the residue which will be left in your mouth right after you smoke THC. It has not been metabolized by the liver. It will leave the saliva in a matter of hours. Therefore, in order to get caught in a saliva test for Δ9-THC, that means you were smoking right there at work. Shame on you sir, but you still have a good chance of passing, just use a regular peroxide mouthwash or other method herein described. Δ9-THC will typically be detectable one hour after use and for up to 12 to 13hours.[2]

Some saliva tests may test for THC-COOH, the metabolized form. This requires that the drug reach the bloodstream, get metabolized by the liver, then reach the saliva through the salivary glands. For this reason, tests which look for THC-COOH may be able to detect drug use slightly beyond 30 hours.

Q: How long does thc stay in your saliva drug test?
A: THC can be detectable in your saliva for up to 72 hours.

Q: What is the difference between mouth swab test and saliva test for cannabis?
A: There is generally no difference. People confuse an oral fluid test for drug residues, which your drug test is, with a cheek swab test to collect cells to test for disease or collect dna. Drug tests aim to collect oral fluid, not cells. The swab may be placed under the tongue, between the cheek, or anywhere saliva is freely flowing.

Pros and cons of a saliva test

A mouth swab test versus a urine test

An oral fluid test will give a detection window of about 3 days, for drugs which were consumed orally very recently and have left residues in the mouth. Some amount of metabolized drug may also reach the saliva after having been processed by the liver. This can show up in the saliva and be detected.

A urine test can discover cannabis uses for up to 30 days.

Oral Fluid Test versus Blood Test

A blood test can also discover drug use for up to 30 days, while a saliva test covers only about 3 days of very recent drug use. The oral fluid test is less invasive and easier to observe. An oral fluid test is less expensive. It also collects less personal information, as the blood can be used to collect lots of information including DNA for unauthorized uses. Unauthorized information can be sold to other companies and can even be stolen by hackers employed by foreign powers or governments. In 2020, a security breach at a payment processor exposed medical records of LabCorp and Quest Diagnostic clients.[3] You want to limit the giving of your biological material to companies as often as possible. In the future, it may even be possible to target biological weapons at people with particular genetics.

Oral Fluid test versus Hair test

A hair test can detect drug use for up to 90 days. It is invasive in that hair can be tested for dna. Cut hair not containing the follicle cannot be tested for nuclear DNA but can still reveal mitochondrial DNA. A hair test is expensive. It takes up to a week for drugs to be detectable in hair, while taking only minutes to about an hour to be detectable in saliva.

How can I pass a cotton swab drug test with mouthwash?

Home remedies to pass a saliva drug test for marijuana

Peroxide method

Peroxide is an oxidizer which will destroy some drug residues and may work as an adulterant to help foil a drug test. Being frequently used as a mouthwash, it is unlikely it will be flagged as an adulterant. Simply take a little swig of 3 % peroxide mouthwash such as you can get at any grocery store, mix it with a swig of water, swish for one minute and spit out. Then take your test, you have a good chance of passing.

The real trick is that you have to do this right before the test, and mouth swab tests are often random, on-the-job, so you have to have some peroxide on you, in your desk. So stash a small bottle of peroxide in your desk. When asked to submit a drug test, take a break, go to the bathroom and swish your peroxide mouthwash for a minute and you’re ready to go.

How to pass a oral swab drug test for pot with detox products

Toxin Rid mouthwash is a trusted product, however we are unable to discover the exact ingredients. Just swig one third, swish for three minutes, spit it out. Repeat with the rest of the bottle. 9 minutes swishing seems like a lot and will raise suspicion so likely you want to swish for just one minute per swig. Our verdict is hydrogen peroxide is likely more effective, but if you prefer a detox product, this is a popular choice.

This Stinger Mouthwash is another popular choice. The unique thing about this mouthwash is that you can swallow it when done swishing. It contains niacin, some sugars and amino acids.

This Amazon review is skeptical that the product works. For the record, Stinger detox also sells detox drinks which do not contain creatine, making such products suspect as they require the drinking of large quantities of water without replacing the creatine. This may mean they are not carefully crafting their products to ensure a good result. Reviewers have claimed their product returned a dilute result, which is exactly what you would expect for a dilution product which does not contain creatine. This could be said to be a rookie error, but a company which sells detox products should either know better, or they are intentionally leaving the creatine out to sell more of a cheaper product. On the other hand, they use niacin and some other attempts at foiling drug tests for their detox drinks; however, take a creatine supplement with it if you decide to use a Stinger detox drink. If you use the mouthwash, perhaps also use a peroxide rinse which is more likely to be effective. Sometimes people want the peace of mind of buying a professional product or just having spent lots of money on their attempt. If such is the goal, Stinger mouthwash fulfills that requirement. It costs significantly more than peroxide mouthwash.

Conclusion: Can you beat fluid swob cheek tests naturally?

Yes, the simplest, cheapest, and most effective way is to simply use a peroxide mouthwash for sixty seconds just before your test. You may be given 10 minutes for your mouth to fill with new saliva but this step may frequently be skipped by untrained testers or technicians in a hurry to fulfill the unpleasant task for probing other people’s mouths for medical information. Just abstain as soon as you know you are going to be tested. You should have hydrogen peroxide (regular grocery store stuff) stashed in your desk. Just use it as a regular mouthwash just before your test and you will have a good chance of beating a saliva test. Use at your own risk and not in jurisdictions where doing so may be illegal.


[1] “Police and Addiction | Psychology Today.” 30 Mar. 2018, Accessed 1 Aug. 2020.

[2] “Oral fluid cannabinoid concentrations following … – NCBI – NIH.” 17 Aug. 2013, Accessed 2 Aug. 2020.

[3] “LabCorp security lapse exposed thousands of medical ….” 28 Jan. 2020, Accessed 8 Aug. 2020.