How Long Does Weed Stay in Your System?!

Welcome to the most comprehensive guide you will find for determining how long weed can stay in your body for.

An important point that needs to be made is that all of the tests for weed, or at least the vast majority of urine tests, only check for THC, so CBD users have nothing to worry about other than the rare chance a false positive comes up through contamination.


The Drug Tests and How Each Type Effects Your Chances

A total of four different tests can be used to detect the presence of THC in your system, each having limits of accuracy in determining if you have been smoking. They include the following:

The urine test for weed is the most common for one very important reason: it will detect marijuana use for as long as 100 days from the last time you used it. There are a lot of factors that come into play, such as your personal metabolism, how often you smoke weed and how heavy of a smoker you are. The difference is between how long you smoke (over days or weeks) and how much you smoke (per day). As an example, one study provided evidence that if you smoke 2 – 4 times per week it will take about 2 and a half weeks to clear your system. If you smoke 2 – 4 times per month it will take a bit more than 30 days to clear your system. We have a comprehensive article on how to Puff Puff Pass your Next Drug Test.


Saliva is the next test we will look at, and the good news is this is the test most commonly used to test for DUI/OUI by the police. It is good news because the saliva test only detects use over the past 12 hours. Employers will also use the saliva test for random on-site testing.


Testing for THC content in blood is not done very often because, like the saliva test, evidence of THC is only present for 2 days – in general. Like the urine test, the more often you use it the longer time it will take to clean your system. Regular or heavy weed users will have THC in their blood systems for as long as a week. One of the biggest reasons that blood tests are used is that they are a far more reliable indicator that the user’s judgment is impaired, so for DUI/OUI arrests and accidents that occur on the job, a blood test is more likely to happen.


Finally, there is the hair test. We saved the worst for last for two reasons. One is that it is the hardest test to cheat on. Two, THC can be detected in your hair months after you completely stopped smoking. A critical factor in testing is the length of your hair. The longer your hair, the better the chance that the presence of THC will be detected. So at least get a trim.


Wait. This has to be qualified because we were talking about the hair on your head. The research continues, but the presence of THC can show up in body hair for as long as one year. At the least, 6 months. So the idea of getting a trim may be more difficult for some people than others.

Detection Prevention – Preventing a Failed Drug Test

Other than for information purposes, this article would be basically useless if it did not have some information on how to reduce or eliminate the presence of THC in your system. Whether you plan on smoking before driving home from work or are going in to a pre-screening test for a job interview, knowing how to clean out your system has its advantages. We mostly covered the test for hair, head or body. The less, the better. No hair anywhere equals no test possible. Other than that, hope for a head hair test.


For the other tests, people who are actual users say that exercise is one of the best ways to rid your blood, saliva, and urine of THC. Connected with exercise is a second option – drinking a lot of water to flush out your system. Your kidneys will only process so much water per day, so there is a built-in limit to how effective water consumption can be. 420 times is too much. But the anecdotal evidence says it is definitely worth a try. Some say cranberry juice is more effective because it is both an antioxidant and a natural diuretic and actually masks the presence of THC and other toxins in your system.


Another piece of advice is to reduce the total amount of your body fat. THC is stored in your body’s fat cells, and believe it or not, you need a certain amount of healthy fats to have healthy hair. That may be one of the reasons the hair test has the greatest testing longevity and accuracy. But your overall body fat content is a key to how long THC will remain in your system. The less the better, which is one reason exercise and hydration are two widely accepted ways to rid your body of THC.


If you want to read up on additional tips for passing a drug test, check out our article here.


The last word on the subject will be given to Ryan Vandrey, Associate Professor of Psychiatry and Behavioral Science at Johns Hopkins University who says, “… there is no way of predicting or knowing how long someone would test positive with any kind of certainty.”

Author: Justin Meerkat

Cannabis Entrepreneur & Cofounder | Follow @justinmeerkat on Instagram

Justin Meerkat

Cannabis Entrepreneur & Cofounder | Follow @justinmeerkat on Instagram

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