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How many days do you have to be clean for a mouth swab?

A mouth swab drug test, also known as an oral fluid test or saliva drug test, is a method of detecting recent drug use by collecting saliva from inside a person’s mouth and testing it for the presence of drugs or alcohol. Mouth swab drug tests are becoming increasingly popular compared to other testing methods like urine or hair testing because they are less invasive, faster, and easier to administer. But how long do drugs actually stay detectable in your saliva? Here is a detailed look at mouth swab drug test detection times.

What is a mouth swab drug test?

A mouth swab drug test, also known as an oral fluid test or saliva test, collects saliva from inside the cheeks, tongue, and gums to test for drug use. An absorbent collection pad is placed into the mouth and moved around to absorb saliva. This saliva sample is then tested at a lab or with an instant testing kit to look for the presence of drugs.

Mouth swab tests can usually detect drug use that has occurred within the past few days. They are best at detecting very recent drug use compared to urine or hair testing. The exact drug detection window depends on the drug itself as well as dosage and frequency of use.

How long do drugs stay in your saliva?

Most drugs can be detected in saliva for between 24-48 hours after last use. Heavy or chronic drug users may produce positive saliva tests for slightly longer periods. Here is a look at the typical saliva drug test detection times:

Marijuana – 1-3 days
Cocaine – 1-2 days
Methamphetamine – 1-3 days
Opioids – 1-4 days
Benzodiazepines – 1-5 days
Alcohol – 12-24 hours

As you can see, the detection windows for saliva tests are quite short. Most standard mouth swab tests can detect drug use about 1-3 days after last use for the average person. Chronic heavy users may have slightly longer detection times.

Detection Times for Marijuana

For marijuana mouth swab tests, THC can be detected in oral fluid for 1-3 days after last use for most people. In some cases, THC may be detectable for over a week in those who use marijuana repeatedly or in high doses. The typical marijuana detection windows are:

– Occasional users: 1-3 days
– Moderate users: 1-7 days
– Heavy users: 1-29 days
– Chronic users: 7-90 days

As you can see, detection times can vary considerably between occasional marijuana users compared to chronic heavy users. But for most people, marijuana will only be detectable for 1-3 days in a mouth swab test after last use.

Detection Times for Other Drugs

Here is a quick look at the typical oral fluid detection times for other common drugs:

– Cocaine: 1-2 days
– Amphetamines: 1-2 days
– Methamphetamine: 1-3 days
– Benzodiazepines: 1-5 days
– Opiates: 1-4 days
– Barbiturates: 1-3 days
– MDMA: 1-2 days
– PCP: 2-4 days

Heavy or chronic use of these drugs may result in slightly longer detection times. But for most individuals, these drugs will only show up on a mouth swab test for 1-3 days after last use.

How to Pass a Mouth Swab Drug Test

If you have an upcoming mouth swab drug test and have used drugs in the past few days, the most reliable way to pass is to abstain from drug use for:

– Marijuana: 7 days
– Cocaine: 2-4 days
– Methamphetamine: 2-4 days
– Opiates: 5 days
– Benzodiazepines: 5-7 days

If you only used a drug one time or very occasionally, the detection periods will likely be on the shorter end. But allowing at least this much time since last use gives you the best chance of testing negative on a saliva drug test.

You can also use mouthwashes, brush thoroughly, and drink plenty of water before a saliva test – but this is not guaranteed to help beat the test. The only surefire way is to abstain from drugs long enough for your saliva to clear any traces.

Factors That May Impact Drug Detection Times

Some factors that can affect detection times in saliva include:

Drug potency – More potent forms clear faster.

Dosage – Higher doses take longer to clear.

Frequency of use – Frequent use results in longer detection times.

Fluid intake – Hydration can help dilute saliva.

Medications – Some meds impact excretion.

User’s metabolism – Faster metabolism equals quicker excretion.

Collection method – Swabs versus oral fluid tests.

Test sensitivity – Some tests are more sensitive than others.

So while approximate saliva drug test detection times are known, many variables can alter these windows. Testing negative always requires abstaining from drugs for at least several days.

Mouth Swab vs. Urine vs. Hair Drug Testing

Mouth swab tests are quite different than urine or hair tests in terms of how far back they can detect drug use:

Test Type Detection Window
Mouth Swab 1-3 days
Urine 2-5 days for most drugs
Hair Up to 90 days

As shown in the table, mouth swab tests look for much more recent drug use compared to urine or hair tests. But mouth swabs are easy to administer and less intrusive than the alternatives.

Can Mouthwash Help Beat Saliva Drug Tests?

There are many claims that using mouthwash before a saliva drug test can help beat the test. Mouthwash aims to dilute saliva temporarily and wash away traces of drugs that may be detected during testing.

However, research has shown that mouthwash use has mixed results when it comes to passing a saliva drug test. Some studies have found that mouthwash can help lower saliva drug concentrations for a short period of time. But it is not guaranteed to help you pass, especially if you are a frequent or recent drug user.

Ultimately, abstaining from drug use for a sufficient window of time is the only reliable way to pass an oral fluid drug test. Using mouthwash shortly before the test may help slightly, but it is not a solution on its own. The best advice is not to count on mouthwash to beat a saliva drug test.


In summary, for most drugs mouth swab tests can detect use within 1-3 days. Detection times vary based on the drug itself, dosage, frequency of use, and other factors. To pass a mouth swab drug test with certainty, abstain from drug use for at least 5-7 days beforehand. Mouthwash may help slightly, but is not guaranteed. The detection windows for saliva testing are quite short, but avoiding any drug use for several days is the only sure way to pass.