How Long Does THC Stay in Your Saliva

How Long Does THC Stay in Your Saliva?

As more and more states regulate medical and recreational marijuana, saliva tests are becoming increasingly popular for employers. It’s not surprising that people are nervous, how long does THC stay in your saliva? If you smoked a joint last night, can your employer do a quick test in the morning and kick you off the job site? What if you smoked last week? Or last month? Jobsite testing is a reality these days.

The difference between a urine test and a salvia test comes down to what question the test is looking to answer. In a urine test, the tester wants to know if someone uses cannabis at all. In a saliva test, the tester is asking if someone has used marijuana within a recent time frame.

Oral swabs have a short window of accuracy. Employers are looking to see if someone is too stoned to be fit for work. Other times, they may request a random drug screening of all their staff, as random drug testing is usually the most accurate. After all, its hard to prepare for a test you didn’t know about!

What Happens to THC in your Body?

The second you inhale, smoke enters your lungs, and the cannabinoid called THC enters your bloodstream. The bloodstream circulates throughout your body for upwards of six to eight hours until cleansed by the liver. Unfortunately, if you have a urine test in your future, it’s going to take more then time to cleanse the body of THC.

Many of the compounds removed from the blood are transformed by the liver into new compounds. This process includes the THC molecule. The liver turns THC into something called THC COOH. This new metabolite becomes a problem because it sticks around in the body’s fatty tissues. Depending on your body size and how much weed you smoke, it can potentially linger for months.

Urine, hair, and blood tests all look for this long-term metabolite. If you have smoked weed in the past two to three months, there is a chance that these longer terms tests will come back positive for THC COOH.

But what about saliva tests? If you foresee an oral swab in your future, you may be in luck. Saliva tests only test for the active compound, THC. THC is usually just found in your mouth through a swab. In most cases, any trace is absorbed into the bloodstream after eight hours. If you are a heavy user though, THC could potentially linger for longer.

How Do Saliva Tests Work?

As mentioned, saliva tests work by testing the active compound found in your saliva. They cannot check for THC COOH. Most oral swabs currently in circulation are quick, cheap and easy to use. This makes them extremely popular among employers.

An oral test works much like a pregnancy test. It tests for THC based on a specific ratio. The test can only give back one of two answers. Yes, there is detectable levels of THC, or no there is not. Usually, a saliva test uses a ratio between 25 ng/ml to 50 ng/ml.

What Affects the Level of THC in my Saliva?

Although easy to use and quick to test, on the job saliva tests are perhaps one of the least accurate drug tests on the market. Different brands will have varying degrees of accuracy, including varying base levels. On top of the differences between brand names, there are a number of other factors that can influence a positive test result.


For those lucky enough to have a speedy metabolism, it might also speed up the absorption time of the THC molecule through their saliva. There is some evidence suggesting metabolism can influence the length of time THC is detectable through saliva, and also once transformed into the THC COOH.

Potency of Weed

Obviously stronger marijuana has higher levels of THC. Therefore, if you tend to smoke the potent stuff, your chance of testing positive increases. Alternatively, if you prefer weed that has a more balanced cannabinoid content, a saliva test will be far less accurate. Saliva drug tests are only capable of testing for THC, none of the other cannabinoids even register.

Mode of Consumption

Depending on whether you eat edibles, or smoke a joint, your test results could vary. On top of that, if you chose the to eat your weed, it will likely stick around in your system for longer. Inhaling THC goes straight into your bloodstream, but the THC an in edible takes much longer to process through the digestive tract.

How Much and How Often

Probably not surprisingly, if you’ve only smoked one puff over the last few months, there is less THC detectable. It won’t stick around for long. However, if you are a heavy smoker, your system will be rampant with excess THC and THC COOH compounds. The compounds stick around much longer in the saliva of the heavy user.

Overall Health and Wellness

Are you hydrated? Do you ear tons of fruits, vegetables, and clean foods? These may seem like silly questions, but a healthy body promotes a fully functional system. Maintaining an optimal level of health and wellness will provide your body what it needs to detoxify. Without regular exercise and healthy foods, toxins tend to linger.

The bottom line when it comes to saliva tests is that their accuracy varies widely. Despite this, they are increasing in popularity and precision. Keep in mind that a mouth swab can only trigger positive results with recent cannabis use. Although it will vary depending on the circumstances mentioned about, usually it can only find THC up to two days after use. Even a heavy user that abstains for a couple of days, will likely test negative because there will be no trace of THC left in their saliva.

How To Pass A Mouth Swab Drug Test

It’s all well and good to know what kinds of lifestyle changes you need to make to improve your chances on a future drug test, but what about a test tomorrow? How can you pass a saliva test within the next few days? Despite what you might think, there are ways to dilute the potency of the THC in your saliva. There are also ways to cleanse your mouth of any remaining weed traces. Make sure to read our article about how to pass a mouth swab drug test.

Thankfully, THC never lingers long in your saliva. Within 48 hours all traces of THC should have long flushed out of your oral cavity. Even with heavy smokers, you need only be concerned for the first 72 hours.

Still, you might want to try some do-it-yourself oral cleanses before taking the test. There are many oral detox types of mouthwash on the market, but also some more natural alternatives to explore:

  • Stop smoking weed. This step should be obvious.
  • Brush your teeth thoroughly, and much more frequently than usual. 
  • Drink lots of water and chew as much ice as you can.
  • Eat high-fat meals, to help facilitate speedier THC absorption.
  • Cleanse your mouth three to four times daily with vinegar or lemon juice.

While nothing is ever for sure, many pot smokers have reported negative test results after trying one or more of these steps. We’d love to hear from you, what have you tried in the past? Did you pass?