Mouth Swab Drug Test: What Is It And How Does One Pass It?

Last Updated: December 17, 2020

Reviewed by Michael Espelin APRN

A mouth swab drug test (also known as saliva or oral drug test) is used to detect substance use. It is an easy screening method that can detect several illegal substances. It is usually used as pre-employment or post-accidental DOT screening. Read along further to determine how and when mouth swab tests are taken, what substances can be used to detect, and what to do if someone fails it.

What Is the Saliva Drug Test?

Mouth swab testing also included alcohol screening and clinical techniques such as antibodies to HIV, therapeutic drugs, and steroids. The confirmatory techniques used for detection are based on mass spectrometry (MS), emphasizing on Liquid Chromatography-Mass Spectrometry (LC-MS).

saliva test kit ready to be used.

There Are Several Pros and Cons Associated With This Kind of Testing. The Advantages are Listed Below:

  • It is noninvasive that does not cause any pain or inconvenience
  • It gives rapid results for several substances
  • It is easy to administer
  • It is less expensive than urine and blood drug testing
  • It can accurately screen several common street drugs and alcohol.

Apart From the Above-Mentioned Advantages of Swab Tests, there are Some Limitations Attached to It; These are Listed Below:

  • The time that an illegal substance or its metabolites are present in the mouth is much less, thus making the testing time range much shorter.
  • Some medication use can interfere with the testing to give inconclusive outcomes.
  • Some substances cannot be detected by it.
  • Some types of foods and mouthwash can also alter the results.
  • Some drugs can cause dry mouth that can translate to inadequate amounts of mouth fluids, which is not enough to ensure accurate results.

What Substances Do Saliva Tests Detect?

When considering the substances that a swab analysis can detect, they can be divided: 6-panel substance screening and 10-panel substance screening. These are further discussed below:

Saliva 6-Panel Screening

The 6-panel mouth swab drug test is a screening for 6 different drugs and their metabolites. It uses monoclonal antibodies to selectively detect elevated levels of specific drugs in the oral fluid.

octor taking swab sample from a patient.
This Screening Detects the Following 6 Substances From the Mouth Fluid:

Saliva 10-Panel Screening

A 10-panel saliva drug test can detect 10 different substances from the mouth fluid, 5 of them being the most frequently misused prescription medicines while the other five being illegal or street drugs. Since it detects more substances, it is more expensive than the 6-panel one.

The Substances that It Can Detect are:

When Are Saliva Tests Required?

An oral swab drug test is usually required in the following scenarios:

  • Some companies may require swab screening before hiring new employees.
  • They may conduct background checks for some employees, which may include these mouth fluid testing.
  • They may be conducted as random screenings by different companies, organizations, and law-enforcement agencies.
  • They may also be conducted after any incident or accident to check whether drugs may have caused them.

Are Saliva Tests Common?

Swab tests are becoming more common among law enforcement officials and employers because they are cost-effective, easy to administer, and can be conducted anywhere, anytime. They can detect drug races sooner than a urine analysis considering it takes most substances a longer time to metabolize and appear in the urine. Still, they can be detected in the oral fluid in just a matter of a couple of hours.

Man collects biological Specimen.

How is the Saliva Test Administered?

Performing a swab exam is extremely simple, cheap, and quick. All it involves is a collection stick with a sponge or absorbent pad on one of its ends. The absorbent stick is placed between the cheek and the lower gum for a few seconds to a couple of minutes for the oral fluid to get absorbed into it. The individual may be asked not to eat or drink anything 10 minutes before taking the sample. The sample may then be analyzed at that point or may be sent to the lab for detection.

What Makes It Effective?

Mouth swab drug test accuracy depends on several complex factors, but it can be extremely accurate if administered properly. In other words, the sample collection should be done within the detection window, and a good-quality absorbent stick is used. However, what really makes it lethal is randomness. Since it can be manipulated, doing it at random will not give the individual any time to play any tricks.

Detection Window for Mouth Swab Exam

Due to the ease of testing mouth fluids, swab tests are gaining popularity in comparison to urine or blood screening. Different types of drugs show up in the mouth fluid for different durations, which, in turn, determines the detection window for each.

According to the Research About the Interpretation of Oral Tests, the Oral Fluid Substance Detection Windows for the Most Common Illicit Substance of Abuse are:

  • Marijuana, Cannabis (THC): 2 – 24 hours
  • Cocaine: up to 24 hours
  • Heroin: 2-24 hours
  • Opiates: 7-21 hours
  • Methamphetamine: 6 to 76 hours
  • Alcohol: 6-12 hours
  • MDMA: 1-24 hours
  • Benzodiazepines: up to 5 days

The detection window for some of these drugs in the saliva is less than that of urine and blood, whereas, for some drugs, it stays in the oral fluid longer as compared to the other two types of tests. Therefore, the timing of the screening based on the type of substances to be detected is of importance to ensure conclusive and accurate results. For example, based on this study, different cannabinoids have different detection windows in the oral fluid, which affects when and how it needs to be taken.

Doctor and patient consultation.

Oral Drug Test Results

The time it takes for an oral fluid drug test to give the result depends on whether an on-site testing device is being used or whether the samples are sent to the lab for analysis. The lab can take up to 24 hours to give the results, whereas the on-site devices can give the result within a few minutes.

The Results Can be One of the Following:

  • Positive: the substance was detected in the sample
  • Negative: the substance was not detected in the sample
  • Inconclusive: because of certain factors, the results were inconclusive, and the exam should be repeated

The devices used for testing have different chromatographic confirmation methods, biomarker identification, and how they interpret results, as shown in the recent study.

What To Do If One Fails A Saliva Drug Test?

If Someone Fails Such an Exam, it Could be From One of the Following Three Scenarios:

  • The individual takes some prescription medicines, which showed up in the results. In that case, he can provide the prescription so that the failed results will not be held against him.
  • The individual got a false positive, in which case, he can request a repeat screening.
  • The individual consumed some illegal items illegally, which showed up in the results for which he will be held responsible, and subsequent actions are taken.


Page Sources

  1. Olaf H Drummer, Drug Testing in Oral Fluid, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1579288/
  2. Stefano Gentili, Renata Solimini, Roberta Tittarelli, Giulio Mannocchi, Francesco Paolo Busardò, A Study on the Reliability of an On-Site Oral Fluid Drug Test in a Recreational Context, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5005587/
  3. Evaluation of Saliva/Oral Fluid as an Alternate Drug Testing Specimen, https://www.ncjrs.gov/pdffiles1/nij/grants/203569.pdf
  4. Edward J. Cone, and Marilyn A. Huestis, “Interpretation of Oral Fluid Test For Drugs of Abuse”, 2009, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2700061/
  5. Dayong Lee and Marilyn A. Huestis, “Current Knowledge on Cannabinoids in Oral Fluid”, 2015, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4532432/
  6. Wendy M. Bosker and Marilyn A. Huestis, “Oral Fluid Testing for Drugs of Abuse”, 2011, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3165054/

Published on: July 11th, 2016

Updated on: December 17th, 2020

About Author

Peter J. Grinspoon, MD

Dr. Peter Grinspoon is an experienced physician with long-term clinical practice experience. As a former analgesic addict, Dr. Grinspoon knows precisely how important it is to provide patients with effective treatment and support. Medical writing for him is the way to communicate with people and inform them about their health.

Medically Reviewed by

Michael Espelin APRN

8 years of nursing experience in wide variety of behavioral and addition settings that include adult inpatient and outpatient mental health services with substance use disorders, and geriatric long-term care and hospice care.  He has a particular interest in psychopharmacology, nutritional psychiatry, and alternative treatment options involving particular vitamins, dietary supplements, and administering auricular acupuncture.