How Does a Mouth Swab Drug Test Work?

A mouth swab drug test is a screening tool used to detect the presence of certain substances in your system using your saliva.

This type of test is quickly becoming one of the most popular screening tools for drugs because of the ease with which it can be done. It offers almost instant results and is generally low-cost. It is also less invasive than some common tests used to detect substances, such as a urine or blood test.

This article describes what you can expect during a mouth swab drug test and why you might need to take it. It also covers which drugs they can test for, how soon a drug can be detected in your saliva after taking them, why you might need to take a mouth swab drug test, and how accurate a mouth swab drug test is.

What to Expect During the Test 

A mouth swab test is done by swiping the inside of your cheek or underneath your tongue with what looks like a long Q-tip, with a sponge-like material at the end. This can either be done for you or you might be asked to swipe the tool yourself.

You are typically advised not to eat or drink anything for about 10 minutes before the test is conducted.

If the person conducting the test came to your home or place of work, they’d need to take the samples back to their lab to analyze your saliva. But, depending on the kit used, some results can be produced on-site.

Certain kits provide a nearly instant result once the sample has been put on them, and some tests produce results within 24 hours.

Why You Might Need a Mouth Swab Test 

A mouth swab drug test might be conducted for several reasons. It’s particularly common in workplaces that have a strict policy against drug abuse.

Mouth swab drug tests are also ideal for places where frequent drug tests need to be conducted, such as rehabilitation facilities.

In addition, certain industries that deal with transportation, national safety, or public safety are legally required to test their employees for drug use.

Which Drugs Can Be Detected? 

A mouth swab drug test can be used to detect several substances and drugs. Some of the most common drugs tested for using this method include: 

• Alcohol
• Amphetamines 
• Barbiturates
• Benzodiazepines
• Cocaine 
• Marijuana
• MDMA
• Methamphetamine
• Opiates
• Oxycodone

How Soon Can These Drugs Be Detected?  

How soon a drug can be detected and how long it remains present in your saliva depends on the drug being tested for.

Here are some of the most common substances checked for during a mouth swab drug test and how soon they can be detected in your saliva:

• Benzodiazepines: Also known as "benzos," some drugs that fall under this category can be detected for up to 10 days after they’ve been used. However, a benzodiazepine such as Ativan gets metabolized more quickly by the body and may only be detectable for around five days. 
• Marijuana: A mouth swab test can detect THC in your system as soon as 24 hours after consumption.
• Opiates: Most opiates such as heroin are detectable through saliva for about 24 to 36 hours after they’ve been consumed.
• MDMA: More commonly known as ecstasy or molly, MDMAs can be detected through your saliva as soon as an hour after they’ve been consumed. However, these substances pass through the body’s systems quickly and become almost undetectable 24 hours after consumption.
• Methamphetamine: Methamphetamine can be detected using a mouth swab drug test as soon as ten minutes after it has been used. It can remain detectable for up to four days later, especially with frequent users of the drug.

A person looking to take advantage of this only has to wait a few days to circumvent the test and come out clean, depending on the substance used. Some test administers use more than one kind of screening tool to avoid this issue.

There’s no exact science as to how long drugs can be detected in your saliva. Research shows that several factors could affect the detection time of a drug in any individual.

These factors include:

• The quantity of the substance taken
• The route of administration
• The frequency in which the person being tested uses drugs

How Effective Is a Mouth Swab Drug Test? 

These tests are most effective for detecting very recent cases of drug abuse. If a person takes a test just a couple of days after using a drug, a saliva test might not detect it. However, when done promptly and properly these tests are very effective in detecting drug abuse.

Some research does show that citric acid sweets or chewing gum could change the concentration of certain drugs in your saliva. It was shown to reduce concentrations of cocaine, codeine, and methamphetamines to varying degrees.