A marijuana saliva drug test (also known as an oral fluid or mouth swab test) is a non-invasive screening method designed to detect the active presence of Tetrahydrocannabinol (THC) in a person's saliva. Unlike urine tests that look for inactive metabolites, saliva tests primarily detect the parent drug ($\Delta$9-THC), which is directly deposited in the mouth from smoking or consuming cannabis.
- Purpose: Primarily used for detecting recent use (within the last few hours to 24-48 hours) rather than long-term or historic usage.
- Detection Window: THC is typically detectable in saliva for about 4 to 12 hours after consumption, though some tests can detect it up to 24–72 hours in heavy users.
- Procedure: A cotton swab or absorbent pad is placed in the mouth between the lower cheek and gum for 1–3 minutes to collect saliva.
- Results Time: Instant on-site tests provide results in 10-12 minutes, while lab-based tests may take 1-2 days.
- Cut-off Levels: Common cut-off levels for cannabis in oral fluid range from 6 ng/mL to 40 ng/mL, depending on the test manufacturer.