Marijuana: How Long Does it Stay in the System?

How long marijuana stays in your system is dependent on several factors. This includes how frequently you smoke, and the type of drug test used.

It can be difficult to determine exactly how long weed stays in the system. This is because everyone’s body, and metabolism is different. However, below is a general overview of how long marijuana stays in the system.

How Long Marijuana Stays in Urine

thc in urine

(Photo: Smoking Pagoda)

How Long Marijuana Stays in Saliva

thc in saliva


Marijuana has the shortest detection window in saliva. If you’re a daily smoker, studies have shown that in most instances it should be completely out of the system after 72 hours of abstaining from using cannabis, although in some rare cases it can take up to a week for cannabis to leave the saliva. It never, however, will take longer than a week.


Below are some of the factors that will effect how long marijuana does stay in your saliva:

  • Potency: Unsurprisingly if you consume cannabis with a high percentage of THC – the compound that’s tested for – it’s likely to stay in your saliva longer.
  • Frequency of Use: Other than potency, this is the most important factor in determining how long marijuana stays in your saliva. If you only smoke once a month or even once a week, you may pass a saliva test after 24-48 hours of abstaining. For daily smokers, it’s typically out of your system after 48-72 hours.
  • Metabolism: If you have a “fast metabolism”, you’re body is likely to flush the THC from your saliva quicker; this also effects how long it stays in your urine.

THC: How Long it Stays in Hair

thc in hair


Hair tests are the most invasive form of drug test, as even a single hit of cannabis can be detected for a week or longer. Regular users can have it in their hair after abstaining for 90 days or longer. However, hair tests result in many false-positives, so aren’t often used.

For example, a study published last year in the journal Scientific Reports; and published online by the U.S. National Institute of Health; found that it’s possible for someone to test positive for cannabis in a hair test despite having never consumed it. This is because it can get in the hair through secondhand smoke, and contact with someone that has residual cannabis on their fingers.

Passing a Marijuana Drug Test

There is no sure-fire way to pass a drug test if you smoke cannabis. Googling drug test detox products will give you a large list of different products. We don’t endorse any particular one of these, so encourage doing some research and reading reviews. Many people use the dilution method of drinking a lot of cranberry juice and water; this doesn’t always work as planned, however.

The best way to make sure you pass a drug test, as unfortunate as it may be, is to refrain from consuming cannabis for a period of time. If your test is a swab (saliva) test, just a few days will likely do the trick. If it’s a urine test, and you’re a regular smoke, you might need to wait a month or longer.


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