The popularity of cannabis use is growing throughout the United Kingdom, European Union, and the U.S. With this growth comes a greater reliance on saliva drug testing to assess recent marijuana use. For employers, police officers checking at roadside stops, and as evidence of a crime, saliva testing is attractive as it is easy to administer, fast, and requires no invasive procedures.

Below is a detailed overview of how saliva cannabis tests function; what is being detected by saliva tests; and how long THC will be detectible in your mouth.

What is a Saliva Cannabis Test?

Saliva cannabis tests (also referred to as oral fluid tests) analyze a subject’s mouth fluids for THC, the active compound associated with the psychoactive properties of cannabis.

Why saliva testing is so well liked:

• Fast and quick administration
• Private facilities are not required
• There is little risk of fraud
• Recent use is easily detected
• Results can be obtained within minutes (for rapid tests)

Since saliva tests are focused on detecting the use of cannabis within a short period of time, they are generally used to determine if a person has smoked or ingested cannabis recently versus a few weeks prior.

What Does a Saliva Test Detect?

Saliva tests are looking for:

1. Δ9-THC (the active compound)
2. Sometimes THC metabolites, but at much lower levels than those found in blood or urine tests

Important note: Saliva tests do not detect CBD, CBG, or other non-psychoactive cannabinoids.

How Long Does THC Remain Detectable in Saliva?

THC detection periods vary significantly based upon how often you consume cannabis, your metabolic rate, and the potency of the product you have consumed.

General THC detection periods:

• Single or casual use: 6–24 hours
• Moderate use (a couple of times each week): up to 48 hours
• Daily use: 48–72 hours
• Regular heavy use: up to 72+ hours
• Why saliva testing has limitations:
• THC does not linger in oral fluid for long periods of time — it is primarily detectable through the direct contamination of the mouth when you smoke or vape.

Detection windows for edibles are generally shorter since THC enters the mouth differently than it does when you smoke/vape.

When Are Saliva Cannabis Tests Conducted?

Saliva screening is used in the following areas:

• Police roadside stops

Police often depend upon oral fluid tests to confirm if a driver has been using cannabis.

• Workplace Testing

In particular:

• Transportation
• Manufacturing
• Construction
• Jobs that require adherence to safe working practices

• Legal/Probation Cases

If authorities need to quickly verify a person’s short-term cannabis use, saliva screening is also used.

• Pre-Employment Screening

Many employers select saliva tests rather than urine tests because results are quicker.

How Accurate Are Saliva Cannabis Tests?

Saliva tests are regarded as fairly reliable, but there are a number of variables that impact their reliability:

Variables That May Affect Test Results:

• Oral Hygiene (mouthwash may temporarily reduce detectable THC)
• Consumption of food/drink
• Frequent cannabis usage
• Sensitivity of test (cutoff levels)
• Type of product (smoke, vapor, edible)

False negatives and false positives are extremely rare but possible, particularly with subpar rapid tests.

Can You Reduce the Time for Which THC Can Be Detected in Saliva?

No method is guaranteed to reduce the amount of THC remaining in your mouth, but the following methods may decrease the residual THC in your mouth:

• Drink Water
• Brush your teeth and tongue
• Use mouthwash
• Eat fatty or acidic food (this may help break down residue)
• Wait for a couple of hours before consuming more cannabis

These methods do not eliminate THC from the body — they only remove it from your mouth.

Saliva Test vs. Other Cannabis Tests

Saliva tests are the least sensitive among all the cannabis testing options, making them the best option for determining recent cannabis use.

Final Thoughts

A saliva cannabis test is one of the easiest and quickest methods to detect recent THC exposure. Although the time frame for detecting THC in saliva is somewhat short, saliva testing is frequently used for the reasons of accuracy, ease of administration, and the ability to detect recent cannabis use. The better you understand how these tests operate, the more likely you are to make informed decisions about your workplace policies, legal ramifications, and adhere to the necessary guidelines and regulations.