Determining How Long Does Weed Stay In Your Urine, Saliva, Blood, Hair & System

Determining how long does marijuana, pot, THC, weed stay in your hair blood & urinary system and whether there is any marijuana in someone’s urine depends on a variety of factors. The most common drug test is to provide a urine sample for analysis, called a urinalyses. The active ingredient in marijuana is THC, which is responsible for effect of feeling “high” after consumption. As the liver breaks down THC, a metabolite, known as THC-COOH, is produced that stays in the system much longer. This is the chemical a urinalyses detects. Studies on how long pot stays in the urine after abstinence have reported the following averages:

  • First time user is detectable from 5 to 8 days afterwards
  • Occasional usage is detectable from 11 to 18 days
  • *Regular user is detectable from 30 to 45 days
  • Daily users is detectable up to 90 days

*regular use constitutes several times a week

The reason for this is urine contains a higher concentration and longer detection period than many of the other tests. When it comes to the question of how long does marijuana stay in your urine, blood, saliva, hair and system the answer is somewhat unsatisfying. It varies based on a myriad of factors, such as an individuals body type, metabolism but primarily on the amount of marijuana used on a regular basis.


This is based on what to expect in terms of THC-COOH to be detected in their urine.

Determining how long marijuana stays in the system of a human depends on which bodily system is being tested.

  • Blood
  • Hair
  • Saliva
  • Urine
  • Breath

How Long Does Weed Stay in Your Blood?

Pharmacokinetic information regarding cannabinoids, specifically tetrahydrocannabinol (THC), indicates the body following inhalation of marijuana smoke rapidly absorbs these chemicals. The primary psychoactive chemical in pot, THC is by nature lyophilic, i.e., readily distributed to adipose (fat) tissue, as well as the spleen, lungs and liver. Cannabinoids are then released by organs and fat tissue into the bloodstream, where metabolization gradually occurs.

How much THC makes its way into the body and bloodstream depends on three primary variables—how deeply the user inhales the pot smoke, how long they hold it in their lungs and duration of a puff. Typically, a cannabis smoker receives anywhere between five and 30 mg of THC after smoking one, average-sized joint. Plasma concentration of THC peaks quickly within three to eight minutes and decreases just as rapidly, exhibiting a half-life of about 30 minutes. According to numerous studies, THC can be detectable in the blood for up to 25+ days after smoking one joint.

Blood tests for pot, while they are a good indicator of recent use, are administered less frequently due the invasive nature of obtaining a sample and the involved expense. A regular marijuana user will have THC in their bloodstream from about two to seven days.

How Long Does Weed Stay in Your Hair?

Hair significantly differs from human blood or saliva when it is used for drug testing because hair provides a much longer window of detection. In fact, depending on pigment content of hair strands, lipophilicity of hair and THC content of marijuana regularly smoked, THC may remain detectable in hair for up to one year or longer. However, results of hair tests for pot cannot be used to determine when a user last smoked marijuana. In addition, concentrations of THC and other chemicals in pigmented hair are 10 times higher than concentrations found in non-pigmented hair.

Hair follicles bind with THC for longer periods, up to seven days after a single use. However, studies have shown testing hair for traces of THC can cause false positives because of secondhand exposure to marijuana.

How Long Does Weed Stay in Your Saliva?

Meant for “on-the-spot” type drug testing, saliva tests can detect THC up to 24 hours only after smoking one marijuana joint. Be aware that while the U.S. Department of Labor allows on-site saliva drug testing, saliva drug testing is not approved by the U.S. Food and Drug Administration or the Substance Abuse and Mental Health Administration for use with Federal Mandated Drug Testing/DOT.

Although saliva taken from the mouth for testing is quickly turned over inside the mouth, it should be noted that any “rinsing effect” possibly interfering with a positive marijuana drug test result will only persist for two or three minutes. Re-equilibration of THC/cannabinoids within the mucous oral tissues occurs rapidly, which may no longer produce a false-negative test result.

Law enforcement in many parts of the country have started administering saliva tests to drivers they believe might have been using marijuana. THC has a very short lifespan in saliva, but will test positive within about an hour of ingestion and can last about 12 hours.

Factors Which Affect Window of Detection

The reason is can be so difficult to determine just how long someone can be positively detected for weed in their system is marijuana is fat-soluble. Fat-soluble means marijuana (THC) is stored in the fact cell of the body.

Here are the primary variables for determining how long weed stays in your urinary system:

  • Weight
  • Body Fat
  • How Much is Smoked
  • How Often It’s Smoked
  • Potency
  • Metabolism Rate

How to Get Weed Out of Your System Fast — Myths and Facts

While there are products on the market that purport to cleanse your urine, there is no real way to get weed out of your system fast. Flushing your system with fluids will dilute your urine, but won’t necessarily remove the THC-COOH from your body. It simply takes time.

6 ways to get marijuana out of your system

All these numbers are averages and, as we discussed earlier, are unique to different individuals. It is likely that marijuana testing kits will be improved in the very future due to the greater accessibility of the drug, making it harder to avoid testing positive especially for regular users.

The technology behind blood, urine and hair testing for THC and other illegal drugs has advanced significantly since testing became widespread in the 1980s. The biggest myth perpetuated today about passing a marijuana drug test is that passing the test may not be possible if you have smoked one joint within 30 days of submitting urine for testing. Flushing the body by fasting and drinking only water may also not remove cannabinoid chemicals from tissues. Nor will consuming certain foods, herbs or vitamin supplements warrant a negative marijuana test, especially if marijuana use was recent and particularly heavy. The one fact that is certain in regards to getting marijuana out of your system in order to pass a drug test is that only abstinence guarantees a negative marijuana drug test result.

As American society eases the legal restrictions on the sale and consumption of marijuana, it’s critical to remember that potential employers are not necessarily changing their drug policies. Many companies require a drug test before hiring new employees, while other businesses, depending on their field of specialty, randomly test their staff. Coming up positive on a marijuana drug test might be grounds for termination.

Abstaining from marijuana is the only stress-free and foolproof way to pass a drug test and, as an added benefit, you will avoid the negative health related side effects as well. These can include breathing problems, depression and addiction among others.


See also;

4 fast ways to get weed out of our system

marijuana addiction

marijuana’s side effects

Can you get addicted to weed?

Smoking weed

Synthetic marijuana

how long does alcohol stay in your urine system


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