How Long Does Marijuana Stay in your Blood?

How Long Does Marijuana Stay in your Blood?

Quick answer:

Calculate The Duration Time For Marijuana (THC) To Last in Your Blood From Last Use:

(select the level of use below)

Light Occasional User
Regular User
Chronic User

in Blood



  • For light occasional cannabis smokers, the average time required for clearing THC in the bloodstream is around 2-10 days or so.

  • For regular marijuana smokers, THC in the blood will clear between 10-45 days.

  • For heavy chronic weed smokers, it can take between 45-90 days for eliminating all traces of THC from the blood.



How Long Does Marijuana Stay In Your Blood?

Long Answer:

Marijuana is the second most popular of the mood-altering substances consumed by people the world over, coming next to only alcohol. This drug, consisting of the dried leaves and flower of the hemp plant; Cannabis sativa, produces euphoria and other effects, collectively called the ‘high’, which lasts for anything from two to eight hours. However, it is the most widespread of the intoxicating agents on a global basis, and thus marijuana drug tests are quite common for law enforcement purposes. Thus, if you happen to be an occasional or regular smoker of weed, then the common query to arise in your mind is about how long does marijuana stay in your blood? The answer to this query is not that simple, and this is because of the multitude of factors that determine the longevity of the active chemicals of weed present in the body of the smokers.

The duration during which THC stay in your blood (active chemical of marijuana) can vary extensively depending upon the regularity at which you smoke weed. Thus, if you happen to have had never had any exposure to marijuana prior to your present smoking stint, then THC will not last in your blood for more than a couple of days, or five days max. However, if you prefer to light up every once in a while, say for example once every week, then the body will take longer to remove all traces of weed from the bloodstream. In case of occasional smokers of weed, the median time required for clearing all traces of weed from the bloodstream is around 2-10 days or so. On the other hand, regular smokers will require between 10-45 days to have all traces of THC and its metabolized byproduct removed from their bloodstream, and come clean in any marijuana blood test. Finally, in case of the heavy smokers the time required for removing all traces of THC from the bloodstream is going to be around 45-90 days.


What is THC & Where Does it get Stored in the Body?

The active chemical of marijuana is tetrahydrocannabinol or THC, which makes use of the fat cells in the body of weed smokers as its place of refuge. Thus, the duration for traces of marijuana stay in your bloodstream can be quite long compared to most other intoxicating agents. Moreover, this makes evading the drug tests aimed at detecting marijuana that much more difficult. THC can remain lodged in the fat cells for weeks in case of regular smokers, and can make its way to a number of important internal organs such as the brain, liver, and the kidneys. In fact, it can stay in the brain for years, which makes smokers vulnerable to detection even years after they might have kicked the habit. Moreover, hair follicles of weed smokers also serve as an excellent place to find traces of THC. In fact, the traces will remain in the body as long as the hair follicles present at the time a person smoked weed remains on their heads.


Marijuana Blood Test:

The marijuana blood test is extremely popular for accurate detection of the traces of the active chemical of weed and its metabolized byproduct in the bloodstream of a suspected drug abuser. However, this test is highly invasive and it cannot really point out the exact day upon which the test subject has smoked weed. However, estimation of the assumed half-life of THC can help in approximating the latest time upon which the suspected person had exposure to cannabis. The level of THC in blood peaks to a high just about few minutes after the consumption of marijuana by a person. At that time, the level of THC in the blood of a weed smoker can get as high as 100 ng/ml or even more. However, the blood concentration of this active chemical of weed decreases rapidly as time progresses since last exposure to weed. The level falls to a low of 1-2 ng/ml and can stay there for around 8 hours. However, this same level can be observed in chronic smoker for more than 24 hours and even a couple of days since their latest smoke.


Factors to Consider:

It quite apparent that people who smoke weed less frequently are clearly at an advantage regarding facing any marijuana drug tests. However, the best thing to do is not smoke it at all because traces of THC are going to remain in the system for quite a long time regardless of what the smokers do to try and remove them. Moreover, the fat content of the body and the rate of metabolism are going to play crucial role in deciding the longevity of the THC in the body of any smoker. A person with fewer amounts of body fat and a higher metabolic rate is going to remove traces of weed at a much faster rate than that of any person otherwise. Therefore, these factors are going to be critical in deciding the duration for which weed stay in your blood.

Moreover, the freshness of the cannabis leaf decides its potency with longer exposure to heat and light breaking down THC, and making the smoke harsher for the smoker. Therefore, those smoking fresher leaves will have higher level of THC in their blood. Thus, smokers need to keep all these factors in mind while deciding whether it would be safe to appear for a marijuana blood test or not. Planning accordingly will help you learn how long does marijuana stay in your blood and in coming clean on any such detection tests.


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