1. How Long Does Marijuana Stay In Your System?
Posted in March 25, 2010 ¬ 1:42 pmh.admin
There are many people who want to know “How long does Marijuana stay in your system.”
While the answer to this question is not simple and straightforward, the fact is that if you
want to use a drug test effectively, it is a question that requires an answer.
So let‟s cut through the misinformation on the Internet and provide one!
Before we understand the period of time that marijuana lasts in the system, there are a
couple of facts that you need to know.
- The presence of marijuana in the system is not dictated by the „high‟ feeling that an
individual gets.
- The presence of marijuana is detected by the presence of the active chemical THC or
Tetrahydrocannabinol.
- The time that marijuana stays in the system depends on the amount of marijuana intake
and the frequency at which it is consumed.
- Marijuana is stored in the body in fat cells. This THC is diffused into the blood stream over
a period of time. As THC diffuses, the body becomes clean again.
- If you consume marijuana continuously, the rate at which THC can be diffused into the
blood is not as fast as the intake. This means that the THC will be present in the system for
much longer.
- Marijuana drug testing can be conducted using saliva, urine, hair and sometimes blood as
the sample. The variation in the amount of time that THC can be detected in these samples
is fairly high.
- The specific window that you need to check for marijuana consumption depends on
whether you are checking this for a teenager you suspect of using for the first time, or a
long standing addict.
The Saliva Drug Test for Marijuana, or How Long Does Marijuana Stay in Saliva?
Marijuana escapes the saliva very soon after consumption. It can be detected by a home
saliva drug test about an hour after intake. The accuracy of a saliva drug test (97%-98%)
will decrease rapidly about 12 hours after the marijuana was consumed. So while a saliva

2. home drug test option may be useful if you want to check on what your teenager has been
up to at the late night party last night, it is not an effective test for long term or less recent
use.
The frequency in which someone smokes marijuana (for example, every day for 6 months,
or just once) has no bearing on the results of a saliva drug test.
The Urine Drug Test for Marijuana
The accuracy and time limit in which marijuana stays in the urine depends on the amount
and frequency of the drug being consumed. Marijuana can stay in the urine for up to 45
days in cases of very frequent, prolonged use. Basically, the more you use marijuana, the
longer it will remain in your urine. If you have just tried marijuana, for example, and that
was your only use, it will probably be out of your urine within a week.
Those who kick the habit after consuming the drug almost daily can still have THC traces in
the urine after a period of 3 weeks and longer.
You do need to wait for about 2 to 5 hours after consumption for the marijuana to appear in
the urine though.
The Hair Follicle Drug Test for Marijuana
Just because it has been over 45 days since you consumed marijuana, do not assume that
there will be no traces of the drug in your system. The drug that you consume enters the
bloodstream and as the blood nourishes the hair, the drug gets into the hair follicles too. As
the hair grows, the hair follicles contain traces of THC that can confirm the intake of
marijuana. However, this process (of the hair growing out of the scalp enough to be cut)
takes about a week and thus it is only a week after intake that the hair follicle home drug
test shall give a positive for marijuana use.
Drugs take a long time to deteriorate in the hair and therefore testing can be done many
days after consumption. A standard laboratory will check up to 90 days but a court or
another law enforcing institution can have hair analyzed for more than 3 months as well.
While hair drug testing provides a good opportunity to confirm whether someone has been
on marijuana, and has the largest detection window, the issue is that this drug is not one of
the easiest drugs to hair test. THC does not always incorporate well with the hair.
Therefore, it is possible that a frequent user may get a negative reading on a hair follicle
drug test while someone who had it just once a couple of weeks back may get a positive

3. result. The hair follicle drug test is therefore not considered to be as reliable for marijuana
as it is for other drugs like cocaine (and for drugs like cocaine, and all other drugs tested for
in a standard consumer hair drug test, hair follicle drug testing is actually found to be better
at catching drug use than urine tests).
So while the question „How long does marijuana stay in your system‟ is pertinent, there are
all of the above factors to consider before an appropriate and correct answer can be given.
Even though there is all this discussion about the whole question, if you are concerned, the
best thing to do is to just go out there and purchase a home drug test and check out
whether you or someone else test clean or not.
- Written by Anne Hamilton of Home Health Testing. You can continue the discussion or
check out our original post “How Long Does Marijuana Stay In Your System” in its original
context over at our blog.