From the Guidelines
To reduce THC in saliva, the most effective approach is to wait for natural clearance, which typically takes 24-72 hours depending on usage patterns. Drinking plenty of water helps maintain normal saliva production and may assist with dilution, though it won't eliminate THC completely 1. Practicing good oral hygiene by brushing teeth, using mouthwash, and cleaning the tongue can temporarily reduce THC concentration in the mouth. Consuming citrus fruits or drinking citrus juices may help stimulate saliva production and potentially dilute THC levels. Some key points to consider when trying to reduce THC in saliva include:
- Avoid smoking or consuming cannabis products before any saliva test, as recent use significantly increases detection 1
- Exercise and sweating don't significantly impact saliva THC levels, unlike with blood or urine tests
- Food and drink consumption can affect saliva composition and flow rate, with acidic foods potentially stimulating saliva production 1
- Refraining from eating, drinking, smoking, and brushing teeth for a predetermined time before sample collection may be recommended by some devices and manufacturers of technologies for saliva specimen collection 1 It's essential to understand that these methods may help reduce THC concentration but cannot guarantee complete elimination, especially for regular users where THC accumulates in body tissues and is gradually released back into bodily fluids including saliva.
From the Research
Methods to Reduce THC in Saliva
- Rinsing the mouth with water can reduce THC concentrations in oral fluid specimens, as shown in a study where statistically significant lower concentrations were observed comparing concentrations in oral fluid specimens collected before and after a water rinse 2.
- Using a mouthwash, such as Kleaner, may also reduce THC concentrations, although the effectiveness of this method is not as well-established as rinsing with water 2.
- Whole milk has also been tested as a potential method for reducing THC concentrations, but its effectiveness is not well-established 2.
Limitations of Reducing THC in Saliva
- Even with the use of mouthwashes or rinsing with water, maximum THC concentrations can still be higher than the cut-off employed by law enforcement, such as the 25 ng/mL cut-off used by the Spanish police 2.
- THC can still be detected in oral fluid for an extended period after cannabis use, up to 8 days in some cases, making it difficult to completely eliminate THC from saliva 3.