How to Pass a Mouth Swab Drug Test [Complete Guide]

Oral drug tests are used to test for the presence in the system of a recent use of THC. Many employers in the United States and abroad require their employees to undergo regular mouth swab drug screenings, and this can create quite a sense of anxiety for those who like to enjoy cannabis, whether for recreational or medical purposes. Because of this anxiety, many are left in the tough position of figuring out how to flush their system of THC in preparation for a drug test, and often have little time to accomplish such a task.

Even though cannabis is now legal under state law in many states throughout the US, drug testing is still a prevalent practice and concern for those who consume marijuana. Many companies view consuming cannabis on the job as essentially the same thing as drinking on the job, which is why marijuana consumption in the workplace is typically banned, even if you live in a pro-cannabis state such as Colorado, California, or Oregon.

Since cannabis was legalized in certain states, there has been a reported increase in the number of drivers who are driving under the influence of cannabis. Though this certainly does not represent the large majority of those who responsibly enjoy marijuana, this uptick in cases has caused authorities to take charge, increasing the number of roadside drug screenings.

This increase is likely due to the fact that legalization often encourages more individuals to turn towards cannabis, because of its wider acceptance. This, in turn, leads authorities to take a deeper interest in testing those who are consuming cannabis, particularly in potentially dangerous situations such as being behind the wheel.

If THC is found in your system during a roadside swab, this can result in a DUI and a big mark on your record. Understandably, those who are responsible consumers who do not smoke cannabis behind the wheel may want to find a way to flush their system of THC so that they do not fail a random screening.

This, in turn, leads authorities to take a deeper interest in testing those who are consuming cannabis, particularly in potentially dangerous situations such as being behind the wheel.

Throughout the years, people have tried endless methods to pass a drug test, from cranberry juice to vinegar, to excessive amounts of water, bread, and even goldenseal. Although some may swear by these methods, it seems that drug screenings really aren’t impacted by those techniques. Plus, those who are conducting screenings aren’t idiots – they’ve seen every trick in the book so they know what to look out for and it can be rather hard to fool them.

It’s important to remember that home remedies like detox drinks, excessive water dilution, and various detoxes have been proven to be counterproductive to your end goal.

Mouth Swab THC Tests: An Overview

The important thing to know about this kind of drug test is that weed can only be detected in the system for a short period of time. There is a relatively low risk of testing positive for THC during an oral swab, even if one is a heavy smoker, so be it that the individual has abstained from cannabis for at least 24 hours. Urine tests are far more complex and require much longer to pass and should not be treated in the same manner as an oral test.


For those who like to enjoy cannabis, even if regularly, the mere 24 hours of abstinence is great news.

If you are going to undergo a drug test and have an option of which kind of test you prefer to take, it’s generally best to do a mouth swab test since the THC can’t be detected in the system for very long. However, there could come a time when you’ve consumed marijuana during your lunch break, and your boss then decides to implement a mid-afternoon drug test.

In this case, it’s naturally in your best interest to know how to pass a mouth swab drug test, and how to go about passing a drug test naturally.

So without further ado, let’s take a closer look at this type of drug testing, what it entails, and most importantly, how to pass it with flying colors.

What Is a Mouth Swab Drug Test?

Sometimes also referred to as a mouth swab drug test, an oral fluid test, or a saliva drug screening, as implied by its name, this process takes saliva from inside the mouth and examines it for drugs.

This form of screening is reasonably new, but has become more popular in recent years because it’s:

  • Non-invasive
  • Convenient (without a need for a medical professional)
  • Easy to administer randomly on-site
  • Instant results
  • Cheaper than the more common urine test
  • Challenging to tamper with

For those who just consume cannabis, a saliva test is the one you should be hoping for, as it is far easier to pass. A saliva test for consumers of other drugs, however, is much more challenging to pass.


Used to test for alcohol, cannabis, methamphetamines, cocaine, and amphetamines typically, oral swab tests have a wide range of uses and screen for completely different substances than other popular tests, such as urine screenings. Some drugs will remain in an individual’s system for far longer, and therefore must be treated differently. Typically, urine screenings test for the presence of the compound THC-COOH (the metabolite produced by the body once THC breaks down), and saliva screenings test for just the “active” version of THC, or whatever is in your mouth right after smoking cannabis.


Mouth swab tests for cannabis have their pros and cons; they cannot detect cannabis metabolites that might be lingering in your system, but they can discover THC that gets left in your saliva.

Which Employers Use Mouth Swab Drug Tests?

Now that we’ve covered what mouth swab drug tests are, let’s review which employers typically opt to test their employees.

In reality, there are many companies that make use of the good old oral drug test. Typically speaking, these companies will have a testing policy in place that will explain to applicants and employees how, and when, they will be subjected to illegal drug testing.

Drug testing is mainly used in association with union agreements, or in areas of employment that are safety critical such as transport and energy generation. We are also seeing an increase in the use of drug testing in the construction industry.

Drug testing is also a common practice among federal employees, specifically those who handle classified information, as well as those who work in law enforcement, national security, and those whose duties include protecting life, health, property, and safety.

We are seeing that a swab test is being used increasingly by law enforcement, as well as employers across the United States. Employers who are wanting to prevent people who either use legal or illegal drugs are turning to drug testing.

Essentially, even 100% legal use of marijuana can still prevent you from gaining or keeping employment, so always ensure that you are aware of the drug testing policy that’s in place with your employer.

When Do Employers Use Mouth Swab Drug Tests?

Each employer is different, but typically there is a set pattern for when a mouth swab test might be required. These moments include pre-employment, random drug screening, background test, and post-incident.

Here we will examine each:

  • Pre-employment – Some employers have a corporate policy that requires every potential employee or applicant to be drug tests before the possibility of employment. At this stage, a potential employee has fewer employment rights and is quite vulnerable without the support of a union or many employee regulations. Because of this, employees are able to require drug screening without much notice.
  • Random screening – This occurs when a selection of random employees are screen for drugs at regular intervals. During this process, there is little prior notice, though the employer must make clear that a randomized screening is probable. State by state laws dictate how much advance notice, if any, is required for the notification of a drug test.
  • Background test – This process is typically conducted alongside other background tests, either before employment or before an employee is selected for a promotion.
  • Post-incident – This type of drug screening is typically the purpose of determining liability after a workplace injury has occurred. This includes damages and near-miss accidents as well. Sometimes, a screening is automatically conducted, and other times it is only suggested if a higher-up determines that drug use could potentially be at fault.

Do I Have to Take a Mouth Swab Drug Test?

The reality is, an employer cannot, under any circumstance, force their employee or employment candidate to take a saliva drug screening. The result of a refusal, however, may mean the loss of a job or potential employment opportunity. In addition to employees being able to refuse, employers can also revoke a candidate’s offer or suspend an individual who has already been hired.

If you undergo a drug test and fail – or believe the results to be inaccurate – there is the possibility that you can either have another test done or have the specimen reviewed again, and in some states, you may request the affirmative right to explain or refute a test, or otherwise demand that another method of testing (such as a blood test) be conducted. Your employer should have a process in place for cases such as this.


Lastly, if your acting skills are on point and you feel daring, you could stand absolutely firm in the fact that you are innocent. You can act surprised at the result (not at all angry or aggressive) and concerned or confused by the outcome. You will need to be very convincing and possess somewhat of a conniving streak to pull this off, though. (And for the record, we don’t condone this option.)

In summary, the choice is entirely yours – if you don’t feel comfortable taking a drug test, don’t allow yourself to be pushed into it. However, you should be aware of the possible consequences. But at least you know you have a few options.

Federal and State Drug Testing Laws

The policies surrounding drug testing vary from state to state. The Supreme Court has ruled that although drug testing may infringe on an employee’s privacy, it may be necessary to protect the health and safety of others. Generally speaking, state laws are similar to federal laws and maintain the legality of drug testing amongst state employees.

As we have established, many private employers require that their employees undergo drug testing. The state and local laws vary in the manner in which they protect the privacy of private company employees’. In many states, private employers are legally allowed to test employees for health and safety reasons, to prevent illegal activity in the workplace that may result from drug use, or to increase productivity in the workplace.

While some states differ in the circumstances that they allow to prompt employers to conduct drug or alcohol testing, others have limits with regards to how and when drug testing can be conducted.

The Drug-free Workplace Act of 1988 is one of the federal laws that was designed to target substance abuse in the workplace. This is a law that legally requires certain employers to take action against drug use in the workplace, like developing a written policy. Law requires industries such as defense, aviation, and transportation to test some employees and applicants for drug use.

Marijuana laws are changing rapidly with the majority of states legalizing it either for recreational use or medicinal use or considering to legalize it. It’s important to keep in mind that some states have only decriminalized weed rather than making it fully or partially legal. You will need to keep up to date with the changing laws to make sure that you are always on the right side of the law.

Overview: Who’s Afraid of a Saliva Drug Test?

As we discussed above, the process of saliva drug testing seems to be on the rise. This is especially true since we are seeing an increase in marijuana use across the United States due to the rapid rate of legalization. Typically speaking, anyone who works in federal employment or work which involves issues of health and safety, should expect to undergo drug testing.


This does not mean that people in other areas of employment are not at risk. There still runs the possibility that any employer across the States may conduct drug testing for various reasons. In fact, drug testing has become somewhat of normal industry practice in many business sectors. This is thanks to a greater need for a sense of security regarding worker performance and of course, “on-the-job” safety. Jobs that require great skill, dexterity, form, and awareness, are naturally, likely to include drug testing as part of their employment policy. This is especially true if there is a high risk of injury or equipment damage

Jobs that require great skill, dexterity, form, and awareness, are naturally, likely to include drug testing as part of their employment policy. This is especially true if there is a high risk of injury or equipment damage.

So when are cannabis users at risk of failing a saliva test? Technically speaking, this will be for as long as the concentration of THC is present in your saliva and is above the lower threshold that the test can detect. According to experts, this is called the “confirmation cutoff.” The cutoff will vary, depending on who manufacturers the test, as well as the different legal limits of different states.

To keep it simple, without going into too much scientific detail, you will likely be in the clear after one to two days of abstaining from weed. To be safe, you should probably give yourself a week to play with. That is, of course, if you don’t know how to pass a saliva test, which brings us to our next point.

Knowing How to Pass a Saliva Test

The most crucial information when it comes to passing a saliva test is knowing what the swab test is looking for and how long you’re at risk for. If you are expecting a saliva drug test in the next few days, you could just hold off on smoking for a few days prior.

THC is not present in the saliva for very long. In fact, THC metabolites that make their way through your saliva glands and into your system, won’t probably show up on a swab test. These aren’t the chemicals that the test is actually looking for.

Essentially, there is nothing keeping THC in your saliva apart from the fact that after you smoke marijuana, it coats the surface of the mouth. This is the reason that it only sticks around for a day or two, perhaps a week if you don’t brush your teeth. But hopefully, that’s not the case!

This is also why it’s a good idea to practice good oral hygiene. It’s possible that what’s good for the teeth could also flush out any THC molecules that may be lingering. Thus you should brush your teeth more than usual – even up to four times a day before an upcoming drug test. Also pay attention to any areas that you normally overlook. This means your cheeks, gums, and tongue.

Another interesting thing to note is that cannabis edibles reduce the risk of detection. However, nothing can be as sure-fire as abstaining altogether. One intriguing finding is that smoking cigarettes could also be detrimental to your drug test. Smoking anything will open up the cells and taste buds in your mouth, releasing saliva (and ultimately more THC). This is why people often suggest that you don’t smoke at least 48 hours before a swab drug test.

Extra Tips for Beating Saliva Drug Test Detection Times

Although we have covered a few tips above, let’s face it, these will only be plausible if you are aware of an upcoming drug test a few days prior. But often, you won’t be given an advanced warning – you will merely find out on the day (with a few hours to spare if you are lucky enough) that you will undergo a drug testing.

This can, of course, present quite a predicament to the would-be drug “testee”: if your employer tells you to undergo an oral swab test at the very last minute with no advance warning, what can you do?

Here are a few helpful ideas to increase your chances that you pass the test with flying colors (okay maybe not that easily), even if you toked up as early as the day before.

How to Pass a Mouth Swab Drug Test with a Few Hours to Spare

If your end goal is how to pass a drug test in 2 days naturally, then your best bet is likely to fill your body with fluids. This will flush all of the metabolites out through the excretory system (although the 2-day mark for complete “cleanliness” is by no means any guarantee).

Swish water vigorously around your mouth, rinse and repeat. But beyond staying hydrated, some people suggest chewing on as much ice as possible. This will not only keep you hydrated but will also dilute the THC content in your saliva to what would hopefully be below the testable levels.

You should also get your hands on the fattiest foods that you can find, as eating fatty food is another great tip that you may have heard before. THC is a fat-soluble substance that will absorb quickly into lipids but not into the water. Therefore, consuming fat before an oral swab drug test could boost the THC absorption rate, which will transform THC into THC-COOH. One thing that’s important to keep in mind though is that while this may get you off the hook for a saliva test, it will increase the amount of THC-COOH that is stored in your fat cells.

How to Pass a Mouth Swab Drug Test with Little to No Warning

Well, we’ve left the worst for last. That is, of course, the worst-case scenario. Your last-ditch effort to pass your swab test is the act of committing adulteration…of your saliva!

Adulterants are chemicals that will interfere with drug tests, and there are new and improved ones coming out all the time. Essentially, though, as every new adulterant comes out and beats the test, companies develop new tests that can detect the new adulterant. It’s like a vicious, never-ending cycle.

Hydrogen peroxide has traditionally been the go-to adulterant for passing a mouth swab drug test. One particular company decided to take advantage of this and has in fact developed little packets of hydrogen peroxide inside chewing gum. The whole process is very simple – just pop a piece of gum into your mouth, break open the packet, and swish. There are also mouthwashes on the market that do the same thing. However, the gum is probably more convenient, and a lot more discreet.

Also important to note is that adulterating your saliva will only keep your mouth clear for a drug test for a half an hour or so, tops. However, as this is the method for emergencies when you haven’t had much warning (or any warning), half an hour will likely be all that you need.

“Quick” Ways to Pass a Drug Test? Don’t Be so Sure…

We get asked all the time, “is cranberry juice good for a drug test?” And our answer is always the same: “well, it is an antioxidant, and some people have claimed it helped them to pass a screening, but we certainly wouldn’t bank on it.”

In fact, when considering cranberry juice to pass drug test, we’d venture to say that those individuals who have passed have done so more out of luck and good fortune rather than the actual effects of the cranberry juice itself.


Granted, if you’re undertaking a several weeks long detox program, by all means, we would recommend drinking as much cranberry juice as possible to help with the natural excretion of unwanted metabolites (such as THC). However, we simply wouldn’t rely on it by itself to get the job done. (Simply put, does cranberry juice help pass a drug test? Probably. Will it guarantee to help you pass if it’s the only thing you use to prepare? Most definitely not).

Unfortunately, the same rings true for those wondering about goldenseal root and vinegar. Drug test companies have long been aware that people try and use ingredients like these to skew the results of the screening. And indeed they are more than capable of doing so. However, as we mentioned earlier, almost any test will be void if it appears that something “abnormal” has taken place. In any regard, if you’re wondering ‘does vinegar help pass a drug test?’, you’re probably referring more to a urine test than a mouth swab test.


Indeed, drinking vinegar to pass drug test has apparently worked for plenty of people over the years. Just read a few forums on Reddit to see what we’re talking about. But trust us, drinking vinegar to pass drug test is NOT an enjoyable process or one we recommend. Side effects like nausea, severe upset stomach, vomiting, and indigestion are likely – and that’s IF you can muster the courage to actually stomach the overwhelming taste and pungent aroma!

All things considered, if you’re wondering how much vinegar to drink to pass a drug test, just do yourself a favor and find another technique. Your body will thank you in the end.


Lastly, you may have heard about some people fudging the results of a screening with a naturally-growing root called goldenseal. Drug test companies have not yet caught on to how exactly to detect for the presence of goldenseal. However, be advised that as is the case with vinegar and cranberry juice, you should NOT rely upon it to provide a guaranteed passing.

Moreover, we wouldn’t even know where to begin to tell you to look for goldenseal root. Drug test agencies generally give you ample notice to plan and prepare for your screening, so there’s no reason why you should have to be scrambling around to every health food store within a hundred-mile radius to find this relatively unheard of natural root.

Final Thoughts on How to Pass a Mouth Swab Drug Test

As we have seen, drug tests are typically more common in specific industries and areas of work, although anybody could have to undergo a test. Drug tests are becoming increasingly prevalent in the workplace. They could even work against you if you get a new job opportunity or a promotion. Hopefully, you can breathe a little sigh of relief with the knowledge that mouth swab drug tests for weed are the easiest to pass.

Hopefully, you can breathe a little sigh of relief with the knowledge that mouth swab drug tests for weed are the easiest to pass.

As we have discussed, there are even methods that you can use to help you pass last-minute mouth swab tests when given no warning whatsoever.

As always, you use all tips at your own discretion, and if necessary, you should conduct further research to ensure that you fully understand all the information we have supplied. And of course, you shouldn’t interpret any of the aforementioned tips and techniques as any kind of guarantee that you’ll pass your particular screening.

Want to know how long THC can stay in your system? Try out our THC Drug Test Calculator.

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