Saliva Drug Testing: Is It Approved By U.S. Officials?

What Is Saliva Drug Testing?

A saliva drug test is a test used to look for recent use of multiple illegal substances. It can be used by law enforcement in legal cases, employers to determine the cause of safety events, companies hiring new employees, or family members trying to protect the safety of minor children. Oral drug screening is permissible in court or employment eligibility in most states (1). Hawaii, Maine, and Vermont do not accept saliva testing in employment or legal cases in 2022.

Saliva Drug Testing

How Is Saliva Drug Testing Done?

Saliva drug testing (2) is done using a mouth swab drug test. There are several different brands of oral fluid testing kits, but they all work similarly. Most oral fluid tests are performed by first collecting saliva from the inside of the test subject’s mouth using a cotton or foam tipped swab. It usually takes 1-3 minutes to collect enough saliva for the test. For instant tests, the saliva will be added to a liquid that reacts to the presence of drugs and can produce results in several minutes. For other types of tests, the sample will be sent to a medical lab like Peace for Health Labs and tested there for the presence of drugs.

What can it detect?

Saliva drug testing can test for a number of different substances. Oral drug testing swabs can be used to look for; alcohol, amphetamines, barbiturates, benzodiazepines, tetrahydrocannabinol (THC), cocaine methamphetamine, opioids, and phencyclidine (PCP).

THC and alcohol are the most commonly misused substances in the United States, followed closely by opiates. There are over 12 million THC users (3) over the age of 12 in the United States in 2022. Many instant tests available for on site use only test for cannabis. Multi-drug panel tests generally must be sent away to be analyzed in labs.

Drugs Detection Times

Both the type of drug used and the quantity of drug used both determine how far back will a mouth swab drug test go. Results can also vary depending on when the test subject last ate or drank anything and how much saliva they produce. A nervous person will usually have a dry mouth which can make oral fluid more difficult to collect. Generally, saliva tests are only accurate when looking for recent drug use. Most drug traces can be detected in saliva for between 5 and 48 hours.

Amphetamine, opiate, and THC detection times

Oral swabs can detect THC for only 48 hours after last consumption. Amphetamines have been detected in saliva samples for up to 8 days (4) after last use, and opiates can be detected for up to 50 hours (5). The method of ingesting does not make a difference in detection times. Whether a drug is smoked, eaten, or injected, the detection times will remain the same. People who are frequent, heavy users of the drug will fall on the higher end of the expected timeframe, while a one-time use will only be detectable in oral fluid for about 5 hours for each type of drug.

Saliva drug detection times

THC Amphetamines Opiates
Up to 48 hours Up to 8 Days Up to 50 hours

On Site Saliva Drug Tests

Saliva drug testing is convenient for roadside sobriety tests and workplace accidents. They are non-invasive tests that do not need to be performed in private. They are painless, and only take 3-5 minutes to complete. Performing an on-site test can protect both the employer in case of liability issues, or the employee if they later file for a workers compensation claim. Most employers have a legal right to drug test (6) any of their employees on site and can discipline employees who test positive, as long as they have a written no-drug policy that the employee has access to.

Some states (7) require that there is “reasonable suspicion” of drug use before an on-site test can be administered. This can be anything from strange behavior to tardiness, and the law is quite vague, usually giving the benefit to the employer.

DOT does not allow saliva testing (8) as of May 2022. The only acceptable tests for DOT employees is a urine sample.

Disadvantages Of Saliva Drug Testing

Cannabis residues are not the only thing in people’s mouths after they consume cannabis. Samples can be diluted by chewing gum, beverages, and eating food. Oral detection tests can be thrown off by both a dry mouth and too much saliva. Some mouthwashes can change the ph levels in the mouth, leading to a false negative test. Many people become nervous when being tested. This anxiety makes their mouth dry, and they become unable to produce the required 1ml of saliva for testing.

While saliva drug testing has been found to be 97% accurate (9), this is only true if you have someone collecting the sample who has been trained on the correct procedure. Some facilities do not correctly train on-site employees to administer tests, and many supervisors do not wish to conduct saliva tests or any other health tests on their employees.

DOT does not accept saliva drug testing for any legal or employment purposes. Also it’s not approved by the FDA or SAMHSA. It is also important to note that more and more employers and state laws allow the consumption of both medical and recreational cannabis.


  1. Ask the experts: Is oral fluid drug testing legal?
  3. Drug Testing in Oral Fluid Olaf H Drummer. Clin Biochem Rev. 2006 Aug; 27(3): 147–159.
  5. 10 Most Commonly Abused Drugs in the United States
  7. Extended Detection of Amphetamine and Methamphetamine in Oral Fluid, Andås, Hilde T. MD
  9. Patient Test information: opioid testing; Labcorp
  11. Can Employers Drug Test On-Site? Andrew David Easler
  13. Drug Testing in the Workplace
  15. Oral Fluid Drug Testing
  17. Field Detection of Drugs of Abuse in Oral Fluid Using the Alere™ DDS®2 Mobile Test System with Confirmation by Liquid Chromatography Tandem Mass Spectrometry (LC–MS/MS) Alex J Krotulski
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