How Long Does Marijuana Stay

If you ‘google’ the phrase, “how long does Marijuana stay in your system?”, you will get hundreds of search results, all trying to talk about marijuana and its metabolites, and how long it is able to stay in a person’s system. It’s rather a difficult question that may not have a straightforward answer. The reason being there are many factors that affect the way a drug stays in body. For example, things like fluid intake, patients condition, drug potency, tolerance, method of use, frequency of use, the patients metabolism, body weight, and fat tissue are some of the many factors that will influence any test results and the detection window.1

What’s Marijuana?

When you talk of marijuana, it’s also referred to as cannabis, weed, herb, spliff, dope, grass, chronic, ganja, pot, bud, boom, skunk, Mary Jane, among other names. In fact there are more than 200 street names for weed. Marijuana is a brown, green, or gray mixture consisting of dry, shredded leaves, flowers, seeds, and stems of the weed or hemp plant botanically referred to as Cannabis sativa.


Weed or marijuana is a common psychoactive recreating drug that alters the mind, it’s also used as a medical herb. It’s the most abused of drugs in the US, as the National Institute on Drug Abuse (NIDA) points out.2

How Long Does Marijuana Stay In System?

Photo of Dried Marijuana & Joints

Image 2 – Photo of Dried Cannabis & Joints

It depends on various things including how much an individual smokes and the kind of method used to test for the drug. You probably got an interview for that dream job you have been looking and now are wondering, “Will I test positive of weed?” Yes, it’s something to be worried of, because it can break or make your dream.

The high you are having today is great, but what about tomorrow, how will it affect your lifestyle including career prospect, relationship, finances, and others? The amount of time weed will stay in an individual’s body will depend on many other things for example, how frequently the person smokes herb, and their health status and weight. Marijuana has over 60 cannabinoids and more than 400 compounds including THC and cannabidiol CBD, as indicated by the National Institute of Drug Abuse (NIDA)1.

As a person continues to take cannabis, the compound THC will accumulate in their body. If you take more cannabis, it also takes longer for the THC to be cleared out of the system. Again, the rate at which an individual metabolizes THC affects how the substance stays in the system. On top of that, the kind of test you are having will also determine if it will show the drug has clear out or not.

How Long Does Marijuana Stay In Your Urine?


Image 3  – Dried Cannabis

The most common way for testing THC in body is a urine sample testing, so how long weed stays in your urine is one thing you want to know. The reason why urine testing remains the most used is because it’s a cheaper method and its detection window is long. Urine and many other tests don’t specifically test for THC, the primary psychoactive chemical found in cannabis, but they test for THC metabolite known as THC-COOH. When an individual has this metabolite in their body system, it indicates that they recently used or processed the chemical.

Depending on the frequency you consume green herb, the length of time may vary. When you consume weed, THC is taken to the body fat where it is stored, so overtime, as you continue taking weed, the chemical will accumulate. The way in which you consume weed probably does not matter, whether you vape, smoke, or eat the herb. And this means that the longer you have it, the longer it’s going to be detectable in urine.

One study5 that was conducted in 1985 had the finding that heavy marijuana smokers are likely to test positive of the drug up to 77 days from the day they quit the joints. Many people who took part in the trial had about 27 days before traces of marijuana could disappear in their urine tests. Yet, another study6 that was conducted in 1989 showed that 13 heavy weed users took 25 days to have the traces of the drug clear from their urine.

Ideally, cannabis will last for the following period in the system:3

  • A single use will take up to 8 days
  • If you frequently use weed, it is going to last for up to 15 days
  • If you are a regular user, it will take up to 30 days
  • When it comes to heavy users, it may take 44 to 77 days in your system.

Because individuals may have different durations of weed staying in their system, as a guide, if you regularly take marijuana, it could remain in urine for a period of up to a month following the last time you consumed or smoked it. So, you want to stay cool and know that this is probably the most frequent and likely method you will have to be tested for marijuana in your body system.

How Long Does Marijuana Stay In Your Saliva?

Sometimes, you could be tested for marijuana by the saliva, so you want to know what to expect, and when, after stopping weed consumption, the period it may take for it to be still detected in your system. The good news is that, THC does take the shortest time in an individual’s saliva.

You have seen the police officers check for alcohol and drugs through saliva. You will have THC metabolites showing up in the saliva, say about 1 hour, following the smoking of weed. The test may remain positive for a period of up to 24 hours, and this may happen even if you had a single smoking episode. If you are a regular user of weed, a saliva test may test positive for up to 72 hours following your last smoking session.

If you are planning to have a saliva test for weed, you may want to stop taking the drug at least for a week. Generally talking, weed can stay in your saliva for the following periods depending on the frequency of use:3

  • A single user may have traces of THC metabolites showing up in saliva up to 24 hours
  • With frequent users, it may take up to 72 hours before THC metabolites clear of saliva
  • Heavy and chronic users will have up to a week before weed clear from their saliva.

While marijuana may stay in your saliva for a couple of hours to days, or even a week, there are ways you can remove toxins from the saliva, especially if you are worried that testing positive of weed is going to affect your lifestyle and life in one way or the others.

When examining the span of time weed will be traced in your body, then saliva and blood try to tie. That’s why those mouth swab drug tests will be examining the same compound that is found in the THC blood tests. When a person smokes marijuana, the substance Delta-9 THC tends to coat the lining of the mouth’s tissue and instead, it is soaked up by the saliva glands. If you take edibles, it means that the exposure of the substance to the mouth tissue is minimal, but again, you are chewing the cannabis in the food. So, there will still be some traces likely to be seen in your saliva.3

It is likely that when you drink a lot of water and brush your teeth or even use a mouthwash, you can help expel the THC that is found in the mouth faster. Taking food containing fat can also help remove THC from the mouth- THC tends to bond to fat.3

How Long Does Marijuana Stay In Your Hair?

While there is contest over whether hair testing for drugs is an accurate method or not, it is still one way in which you can be tested for having THC in your system. Marijuana is believed to have a longer detection window within hair, so will find that all standard hair tests tend to look for traces of drugs in your system over a period of 90 days following the last time you took the drug.

Hair tends to grow at a standard and consistent rate. When testing for drug presence using hair sample, a lab technician takes a short hair at the area that is near the scalp. Hair follicle tests use the part of hair picked from the root to about 1.5 inches, the rest of the hair part (the older part) is discarded. The human hair, on averages, grows at a rate of let’s say, 0.5 inches in 30 days, so when you have the 1.5 inches of hair taken from the root side, it would mean that you are taking the part of hair that has been growing for the last three months, and not the older hair. If you took for example, a foot-long hair, it would mean that you will be detecting marijuana use for say two years back.3

The sample can provide details of your general health and the substances you might have taken in the period of three months. What this means is that, if the last time you took weed was three months ago, you could still test positive of the drug through the hair test.

Depending on what has been ordered in a test, the technicians can provide the required details. THC metabolites may show up in hair, say about seven days after your last consumption of herb, and you may continue to test positive for up to three or so months. However, you will find that hair testing for weed isn’t common, and there are ways in which you could mask the toxins in hair including traces of marijuana so that they are not detectable in many tests. For example, you could use a detox shampoo to coat the hair follicles.

How Long Does Marijuana Stay In Your Blood?

THC and several other active cannabinoids will get into your bloodstream before they can take effect and induce the ‘high’ or changes you want in your body. If you smoke weed, the cannabinoids will get to the bloodstream via the lungs. If you ingest green herb, the THC and other chemicals get to blood through the stomach.3

The blood is the place where potent, active cannabinoids will make their way to an individual’s brain – thus inducing the euphoric sensation of feeling ‘high’ or bringing in the therapeutic effects as with the case of the cannabidiol CBD.

You may want to know that some police that oppose the use of recreational marijuana are trying to prevent the use or driving under the influence with roadside blood tests. If that has happened in your area, you may want to be concerned about it and learn how long marijuana would stay in blood. Though it is not common to have blood tests for weed, it is pretty important you know a thing or two. THC, the main psychoactive chemical found in weed, and its metabolites don’t stay in an individual’s blood for a long period.2

Generally, THC would remain in your blood for the following periods:

  • If you had a single use, it could take up to 24 hours before weed clears out of blood
  • With frequent users, it may last for about 3 days
  • When it comes to regular users, THC metabolites may be seen in blood for a period of up to a week.

So, while having an impromptu marijuana blood test wouldn’t be common, the detection window gives you an idea of how you can keep safe, should the tests come your way.

How Can You Pass a Urine Test?

How Long Does Weed Stay In Your urine? How To Pass Urine Test

Now that we have looked at some of the common marijuana testing methods and their detection window, it would be important if we talk something about ways to pass your urine test for marijuana. The reason we want to talk about this is because urine is the most standard and common way of testing people of marijuana use.

Sadly, if you are a heavy user or smoker of weed, there will be no certain way for passing the urine test. Therefore, you don’t want to make assumptions that you won’t have traces of THC in your urine. There are products you can use that can help mask the traces of weed in urine. For example, you can use detox drinks and detox pills that are meant to clean urine of drug traces. In desperate cases, smokers can try to use synthetic urine to help them pass a urine test, but this can again be very risky.

Urine dilution may work, however, you need to be very careful when doing it. The aim is to flush out THC from the system. Studies7,8 have shown that getting more pints of water before having a urine test is likely to lower the levels of THC-COOH in urine, leading to a negative result. A person is advised to drink a lot of water an hour or so before the test. However, people need to be warned that too much water is perilous to their health, it could even cause death. Having too much diluted samples may mean that they will be rejected for lab testing. So, you need not drink excess of 2 liters of water a day.

There are cases where people have used fruit pectin method to help in cleaning out THC metabolites. When we talk of fruit pectin, it is starch that is derived from produce (the cells walls of the produce) and it is used in preservatives and jams. You can easily get one at a grocery store.

In fruit pectin method, you have the fruit pectin mixed with something like an electrolyte drink, then you take it at least two hours before you have a urine test. Take a large amount of water and some B vitamins. It wouldn’t hurt if you take the fruit pectin and electrolyte drink mix a day or two prior to having the urine test. The way the fruit pectin method works is that because it’s a naturally occurring fiber, it can help expel THC through bowel, and not through urine.

Having said that, it is important to know there is no foolproof way for you to pass urine test, so even after trying the detox and other methods, there are still risks. In case you have a job screening or predict that you will have a urine test, it’s better to stop smoking marijuana until then.

Marijuana Effects on Brain

Areas of Brain that Marijuana acts

Image 4 – Areas of Brain Affected by Marijuana/Cannabis

Marijuana effects on brain

Effects of marijuana on Brain

Marijuana Use Brain Scan

Image 7 – Long Use of Marijuana Mimics the symptoms of Schizophrenia as same areas in Brain are pruned


It’s not quite possible for an individual to estimate how long does it would take for them to test clean of a drug or weed. The best thing a person can do if they predict or know that they have a drug test coming soon, they stop taking drugs. You may also want to consider testing yourself at least two times a week until you get your first clean reading, it would provide you with a reasonable estimate of how long a particular drug stays in your system. It’s important to understand that marijuana metabolites tend to be stored in the fatty tissue meaning overweight users may take longer before they clear the drug from their system.

Reference List

  1. How Does Marijuana Stay In Your System? Available at
  2. Marijuana: Effects, Medical Uses and Legalization. Available at
  3. How Long Does Weed Stay In Your System? Available at
  4. How long does weed stay in your system? Timeframes before you’re clear of drugs. Available at
  5. Excretion patterns of cannabinoid metabolites after last use in a group of chronic users. Available at
  6. Urinary excretion half-life of delta 1-tetrahydrocannabinol-7-oic acid in heavy marijuana users after smoking. Available at
  7. How Long Does THC Stay In Your System? Available at
  8. In vivo adulteration: excess fluid ingestion causes false-negative marijuana and cocaine urine test results. Available at
  9. 10 Secrets Marijuana Smokers Won’t Tell You –
  11. What Does Marijuana Do To Your Body And Mind? –

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