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


How long does marijuana stay in your system? Marijuana use from one-time usage to heavy, chronic smoking will lead to varied time spans that weed stays in the system. It is especially important to be knowledgeable of how long THC metabolites will remain present in your body if you have an upcoming drug test as weed tends to remain detectable for a longer duration than most drugs. In this article, we will look at how this applies to cannabis drug residues persisting in the urine, saliva, hair, and blood as these are the four primary methods of drug testing. Urinary and saliva tests should be noted are more frequent types of drug tests while hair and blood tests are less common. How long does it take to get weed out of your system for a drug test? With the body left to its own devices, this is the same as answering how long THC lasts in your body, but with active detox efforts using products or/and home-made remedies, weed might be undetectable much sooner.

Detection Windows

How Long Does Weed Stay In Your System?

Featured below is a marijuana detection time chart.

How Long Does Marijuana Stay in the Bloodstream

 Of course, a heavy user of weed taking a saliva test, for example, may find that THC toxins are undetectable if the test takes place a week after they stopped smoking; however, it could remain present in the individual’s urine for 29 days or more. How long it will take to get THC out of your system for each of these four potential drug tests will depend on a range of factors including how your system processes drugs and your body fat levels. That is why it is important to take these estimates with a grain of salt. The National Drug Court Institute’s researchers are critical of the idea that marijuana can remain detectable in urine after 30 days. So, they consider any positive urine test to indicated drug use within the last month. Yet, theoretically, marijuana could be hiding out in the fat cells then come flooding out more than a month later in the context of intensive fat burning and weight reduction. In a scientific article published by the organization, it is stated in reference to a 1984 study from Johansson and Haldin that “despite the potential factors restricting interpretation (the study subjects) with exceptionally long cannabinoid detection times (30+ days) were just that—exceptional.”  So, in practice, they found very few people for whom marijuana was detectable after 30 days.

Table 1

Drug Test Type
THC Detection Windows For Various Types of Tests*
One time/Infrequent user Regular User Heavy User
Urine 72 hours 10-15 days 30+ days^
Bloodstream 72 hours 7-10 days 10-21 days
Saliva 1-3 days 1-29 days 1-29+days
Hair 90+ days 90+ days 90+day

*These are estimates taken from a variety of reliable sources and they apply to the average person. For any individual, it may be the case that THC stays in your urine slightly longer or shorter a period than noted. It’s possible that one joint lasts in your system for as little as a day or less if you are not a regular smoker.

As mentioned, this 30+ day estimate could be overestimated although it is a common reference in the marijuana literature.

THC Metabolization

THC or delta-9-tetrahydrocannabinol is the psychoactive ingredient in marijuana which is one of the substances that testers are looking for when trying to detect marijuana consumption in a drug test sample. They may also search for its psychoactive metabolites. THC is metabolized (broken down) in the liver. THC contains over 80 metabolites, some of which can be stored in fatty tissues and organs before being re-emitted into the user’s bloodstream. Of the metabolites that result from the breaking down of THC, TCCOOH and 11-OH-THC are the most important of the lot. Metabolites such as 11-OH-THC (which is still psychoactive even after it has been transformed from delta-9-THC or just THC, again in the liver) are inevitably turned into COOH-THC which is a non-psychoactive metabolite. Eventually, non-psychoactive metabolites will be excreted from your body through the urine. These observations are scientifically founded and backed up by recent research (Sharma, P., Murthy, P., Srinivas Bharath, M. M.).

Types of Drug Tests

As we already discussed, there is a wide range of drug tests including urinary, hair, saliva, and blood tests. Each test uses an array of procedures to search for drug residues with some methods used in multiple test types, such as immunoassay-based testing.

Summary of Tests:

  • Urinalysis: EMIT + confirmation test
  • Hair Follicle Test: ELISA + GC/MS test
  • Saliva Test: ELISA + LC/MS/MS
  • Blood Test: Immunoassay test

Urine Test:

A urinary drug test tends to come in the form of an enzyme multiplied immunoassay technique (EMIT). This is the most common type of drug test. It is sometimes done on the spot, without follow up confirmation tests. Such an approach involves taking a urine sample and testing for an increase of activity in enzymes that are mixed with the sample. An increase in enzyme activity will signify the presence of drugs or drug metabolites. This should pick up on THC metabolites when they are present and thus makes cannabis detectable in urine. A second procedure will be undertaken if the first part tests positive in order to confirm and establish a positive result if the test is important enough to require confirmation. More complex and costly forms of urine tests also exist but if you have a urine test, it’s more than likely going to be a regular EMIT test. How long does it take the pot to leave the system for a urine drug test that may also, therefore, depend on which specific type of urine test you are taking? The cheaper the test, the less time that is likely required for weed to get out of your pee. Cheaper tests may also fail to detect dilution. Most employers will use a regular on the spot urine test without back up the confirmation of negative results. Positive results may or may not be confirmed. If you test positive after a reasonable period of abstinence, you should ask for a confirmation test if one has not been done already.

Hair Follicle Test:

A hair follicle test is certainly not the most common form of drug testing but when it is used, it is one of the most effective forms of testing. They can generally detect THC in a person for a longer period than any other form of testing as weed will show up on hair follicle drug test even if consumed 3 months prior or earlier. Such screenings involve taking a tiny hair sample from close to an individual’s scalp. It is then sent to a lab for analysis. Hair tests, like urinalysis, involves two stages in order to achieve the highest degree of accuracy possible. First, an enzyme-linked immunosorbent assay or ELISA test is undertaken, a rapid method to detect drug residues. An ELISA test involves antibodies being placed on a plastic layer. If there are drugs present, they will interact with the antibodies in particular ways. If the ELISA stage tests positive, then a GC-MS or gas chromatography-mass spectrometry test is used to confirm the initial results. A GC-MS test is used to detect drug toxins by separating substances from one another in a sample and then allowing for the nature of each substance to be analyzed in an effort to search for drugs or drug metabolites in the sample. It is generally not legal to practice to test more than 1.5 inches of hair such that marijuana is detectable in your hair follicles for a prolonged period greater than 90 days, but technically, you could test older hair and discover drug use as long as a year ago.

Saliva Test:

A saliva or mouth swab test involves analyzing a sample of saliva for drug residues. Saliva drug test detection times are not especially long but these tests are usually the second most common form of drug testing after urinary tests, if not the most common depending on the region and/or sector. First, a swab is taken from your saliva glands and this is then collected to be a sample for analysis by the testers. An ELISA test is usually initially used by testers to screen for drug use from a saliva sample. Then a test known as an LC/MS/MS test is used to verify any positive results that emerge from phase one of this drug screening approach. The first step of this phase ‘liquid chromatography’ will separate substances within the sample so that they can be analyzed by a mass spectrometer which will look for any drug toxins present in the various sample components. Cheaper, on the spot testers may not avail themselves of confirmatory tests, so if you are sure you have a false positive, you should quickly ask for confirmation tests.

Blood Test:

Blood tests, like hair follicle tests, are quite rare when it comes to drug testing. Weed stays in your blood system for less time and at lower concentrations which makes it even less common considering that it is more invasive than a saliva test. When a blood screen does take place, it again tends to entail a form of immunoassay testing in an effort to search for drugs such as marijuana in the bloodstream. Before the analysis takes place, you will have blood removed as you would for a regular blood test prior to the sample being sent off for testing or indeed it may be tested at the same facility where your blood is taken.

Possible Ways to Detox:

Natural body detox/quitting weed for a period leading up your test

To be certain that your body is naturally detoxed, you need to abstain from smoking weed for about 30 days. For other drugs, it will take less time to get them out of your system.

 3 days for LSD, to 30 days for cannabis. Amphetamines only hang around for about 3 days, so sometime authorities will demand random testing so that you don’t just abstain when you know a test is coming up.

Detox drinks

Detox drinks will work by a method known as dilution. You will be asked to drink several ounces of water and given a drink containing b-vitamins, diuretics, creatine, and electrolytes. The b-vitamins will make your urine yellow despite it being dilute which would normally make it clear, a dead giveaway that one is trying to dilute the urine. Creatine will replace the creatinine which would otherwise come up as dilute. Electrolytes will prevent water intoxication from drinking too much water which can be dangerous. Any good detox drinks just have to contain the ingredients listed above and should contain no ingredients which can cause an overdose. Mega Clean and other detox drinks by Detoxify are solid detox drinks at reasonable prices.

To detox, the hair, the Macujo, and Jerry G Methods are used. The Jerry G Method is safer in our opinion and merely requires bleaching and dyeing the hair twice over a 10 day period. Most of us have used hair dye before so that’s no big deal. The hair dye should contain ammonia, and you should dye your hair your natural hair color because if the hair looks treated, they may go in for an armpit or groin hair.

To detox, the mouth for a saliva test, just brush real good, then use a peroxide mouth wash. Peroxide is an oxidizer and will oxidize those drug residues.

Detoxing the blood is harder to do safely but basically requires a dilution regimen. Luckily blood drug tests are rare and also unreliable.

Detox pills

Detox pills contain the same ingredients as detox drinks for the most part. The difference is it’s in pill form and you will be ordered to drink several bottles of water in order to carry out a dilution regiment. One exception is Toxin Rid, as it does not contain the typical ingredients and is used in an attempt to actually flush the system rather than to just produce dilute urine.

 Home-made detoxification remedies

You can detox at home using b-vitamins, water, electrolytes (salt, baking soda), and creatine. Many people have these at home already, or you can buy them separately and it will run you cheaper than buying a detox drink. The warning you need to heed at home is that it is not safe to just drink gallons and gallons of water trying to detox yourself. You can get electrolyte imbalances and water intoxication. This will cause swelling of the brain and can result in death. This has happened to people who took water and milk drinking challenges. The body can only handle so much water. So, don’t drink an uncomfortable amount of water trying to detox yourself as this does not work. Weed hides out in the fat cells, not in the bloodstream and you can’t force it out quicker by drinking lots of water. You can only dilute it, or you can try burning fat so that it comes out quicker. If you try burning fat with exercise, you need to stop a few days before your test because if the cells are still leaking THC, much of it will end up in your urine. You have to burn the THC out, then stop the fat from burning just before your test, then you will get only a light trickle of THC into the blood, into the urine, and with a little dilution, you may test negative.


It’s your body and what you do on your own time is no one’s business so being sure you test negative for your drug test is a matter of protecting your body from unreasonable search and seizure as defined in the Constitution of the United States of America. The best way to clean your system for a urine drug test or any drug test for that matter is to simply stop taking drugs for a significant period of time leading up to the test. Detox products are available on the market however and many marijuana users turn to such products or home remedies in an effort to beat a drug test. If you consider this approach, ensure that it is legal to do so in your particular territory first. Defrauding the government of the United States is a federal crime so keep that in mind should you decide to use a detox method in an effort to pass a federally administered drug test.


“How Long Will THC Stay In Your System?” Quora, Quora, 2018,
“Drug Court Practitioner Fact Sheet” Paul L., Cary M.S., 2020,
“Human Metabolism of THC” Rupp, Marlene, Sapiensoup Blog, 2016,
“What Is Tetrahydrocannabinol (THC)?” Medigrowth, Medigrowth, 2020,

This article about Medical Marijuana was published on and updated on December 8, 2020 . Medical facts in this article was checked and article was medically reviewed by our . Author of this checked article is
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Leave a Reply

adultintheroom said:

Please define the parameters for “infrequent”, “chronic use”, and “heavy use”. Much of the article is meaningless without an understanding of your use of these terms.

Rene said:

I have over two weeks before I have to take a drug test. I have stopped smoking completely and exercise about 5 times a week and drink tons of water. Im 5’10 163lbs (not much fat) and my metabolism is pretty fast. Is it likely that I will pass?

Bob said:

First off, let me say you are luck for a reply. There hasn’t been any! lol, but i seen you commented recently and figured i would atleast reply to you as many don’t.
So….I would say you are still cutting it close. most employers want a urine test. THC can take 30 or more days as the metabolites can stay even up to 90 days in chronic or every day users. how frequent you smoke also plays a part as well as how much body fat and your metabolism. from what i ready you have many things working for you. low body fat and the fact you drink plenty of water and exercise 5 times a week. Its still risky though! theres always a chance. if you’re an occasional smoker….it might be in your system for up to 7 days and thats for the occasional smoker. much longer for chronic users. the fact you have over two weeks is definitely a PLUS! but again DO NOT SMOKE ANY LEADING UP TO YOUR TEST! if you do i guarantee you will BE F***ED! Your chances remain atlas somewhat good right now to atleast test below their threshold level and if you do you will be negative. Given you don’t drink a shit ton of water before your test. if its diluted some places won’t accept it. and you may have to retest. also when you drink somuch water you piss clear…. A DEAD GIVE AWAY YOUR TRYING TO CLEAN OUT! also, when you drink hell of water it depletes your creatine levels which they also look for. So My advice…… Keep working out as you are 5 days a week, but i would stop working out about 2-3 days before your test. The given reason is because when you work out your body re-distributed thc and its metabolites back into your system as you workout. thats why you don’t work out 2-3 days before your test. you don’t want to re-distribute whats left in your fat cells back into your urine before the test. Also, keep drinking hell of water, until about a day or 2 before your test. the day before still hydrate your self well but not cramming it down like you will be in the weeks to come before your test. I would take a multivitamin everyday. because your drinking smooch water in the weeks prior to your test you levels are going to be consistently low because you are drinking somuch water. the multivitamin will bring color to your urine back. along with keeping your levels somewhat there. Next Creatine: buy some creatine mono from walmart. I would take 5 grams the days before and the day of the test. this will help bring your creatine levels back up before your test due to the amount of water which depletes your creatine levels. Which they also look for. So you need color in your urine and your creatine levels need to be there. Both a must! As an insurance policy, i would buy a detox drink. I would buy “The Stuff” Note that this is only a mask for leftover metabolites in your urine to help pass the test undetected. Be sure to follow the directions on the bottle. The day of your test. get up early before your set time to take your test. about 4 hours earlier. Drink it. Be sure to follow the directions on the bottle. Urinate 3-4 times before your test and then take the test. If you do these things I’m almost certain you will pass. UNDER NO CIRCUMSTANCE DO YOU GIVE THEM YOUR FIRST MORNING URINE. These contain the most metabolites left in your system. Thats why you want to get up early to drink the detox drink and then urinate 3-4 times BEFORE your urinate for your actual drug test. The is always a risk! but with the time amount that you have…id say your chances are good if you follow the instructions i have laid out for you. Also, Cranberry juice…..DRINK IT! not the sugary ass kind. The less sugar and fats you take in, in this period the better. Eat green foods. Salads if you can. Eat healthy. try to stay away from red meats. they are harder to digest and they slow you metabolism down. you don’t want that since your metabolism is fast. We like that. The faster your metabolism the faster you process whats THC and leftover thc out of your body before the test.


More Information: i recently had a little over 2 weeks to get clean myself. i took a urine test, I’m sure that my piss was diluted, i made sure my color was good, but had little knowledge on the creatine levels which they look for. I didn’t fail, but it made me look a little suspicious. they had me come back to look at the test. the thc line was negative. however it was just a little bit faint. let me be clear. The line was there. i could see it from a distance. it wasn’t like i had to get up on it very close to see. so by faint i mean it was definitely there for negative, but was a little faint than the others which tested for cocaine, etc. etc. which told me i had probably barely reached their cutoff level for thc.
I wasn’t sure what they were going to do. The fact that they had called me back…..i was like shit……here we go. but IF I WAS POSITIVE. they would have told me for sure. further testing wouldn’t have been done, and thats it. Bummer.
But that didn’t happen.
Now they wanted a blood test.
I was quite surprised! i figured maybe a re test for urine, but nope. a blood test!
My guess on why: because my urine was probably diluted, (but i had color to my urine)(assuming my creatine levels were pretty low) because i did drink hell of water up until the day before….they wanted to see if i had either tampered with the urine(which i didn’t) or was trying to dillute(which of course) so my guess is they wanted to see if i had marijuana in my system at that point and time and was trying to just dilute.
Now think…..metabolited stay in your urine much much longer than blood. for someone with thc abstinence of 2 weeks or more your blood should be clean by now. so they shouldn’t find anything. Research i have read ( and i have read everything under the sun!) says that even for chronic users it should be out of you blood by 2 weeks, even less for occasional users (5-7 days)
In a way i am glad that i didn’t have to retest for urine and that they did do a blood test because i haven’t smoked for more than 2 weeks. should of had enough time for my blood to be clean. (I am a chronic smoker. Every day!) (5-7 times a day) (bowls) with similar to you in body weight and metabolism. maybe just a bit taller.
Thats just some more info from my experience. (YOU ARE GETTING GOLD HERE!)

Note: Just so you know the unexpected CAN happen!
I am currently waiting for my results and should hear something today! id say if they are confirming of the blood test. i have a lot better chance at passing as there are detection time windows for blood test.
Thats why when ppl get into accidents, they want blood test to see if they are currently under the influence or recently have been.
But with all the research i have ready…..they already had missed that detection window for blood by more than 2 weeks.
Id say my chances a very good. Still a risk, but very good.

If you want to avoid this possible happening to you you can always just do what i should have done. I would have did it if i had know for sure.
You really can’t go wrong either way…urine or blood. it cleans both! This is the #1 product i have found. ITS THE BEST. a bit expensive but worth it
Its called “Tox Rid”
If you are a heavy smoke, i wouldn’t recommend the 3 day. If you have 10 days… the ten. Order it immediately. stay hydrated (you don’t need to cram water like you have been without tox rid, but do stay hydrated and still urinate.
But if you want a sure 99% chance of passing….
I Hope this forum helps somebody and informs you that even the most unexpected can happen! I never expected that blood test!
Hope this helps! Good luck Troopers!

John Em said:

Hello! Say if one were to be a frequent user for less than a month and only took on half-full hit from a hitter per day. Would this effect the time which one would need to detox, or would the frequency still have the same effect?

Kris said:

Hi just wondering did you pass the blood test ??
Thanks regards

Joey said:

If anyone needs to get clean fast go to your local gnc and buy niacin it has a silver cap dont buy the orange bottle its something different. When u take it feels like ur skins burning but drink plenty of water and when u can take it and not feel the burning sensation your urine is usually clean.

Zipper said:

What’s Gnc? Sounds horrible

Jj said:

I smoked recently but, i dont smoke often.. Im a heavy weight persin about 345lbs.. I need to clean my urine for a drug test.. How can i get clean in about twoo weeks?

Davo said:

Get Urself some good fake urine & make sure temp is between 99°-96° & UR good.

Mary Wilson said:

I’m 31 weeks pregnant how long does thc stay in in my system and when do I need to stop I have till March the 29th is that long enough

Kimmie said:

Go ahead and stop. After 24 weeks it takes longer to get out of your system and if you continue it will be present in babies blood and urine/1st poop if they test baby dhs will get involved if you arent legally able to smoke…

john said:

i’m currently on probation and just smoked, i have not smoked since late november. Yesterday was my first time in 3 months, but i got a call saying i have to take another urine test on March 27. it’s exactly 53 days away, am i good or should i worry?

Karen said:

I have not smoked for 3 months and took a single hit 2 days ago. I am getting blood drug tested tomorrow. Will it show up?

Cody said:

What if u stop smoking after 4 years. Frequently used. Only weigh 140lb and have a high metabolism, at a height of 6.2, workout run pushups and lift everyday and eat only foods like bananas spinich grapfruits avocados cranberry other veggie diet. And while also drinking lemon infused water about 2 or 3 bottles a day, and drinking green tea, and hibiscus tea. Any hope for someone like me being able 2 pass a drug test? And if so about how long do i have 2 stay on this diet? You see i love meat and carbs and very skinny. So i want 2 know so i can get a job finally and go back 2 eating what i want. Please help

Sergio Diaz said:

How long will it take to get weed out of your system like hair wise like I smoked weed like 3 times in the past 2 years and the job I am going to take does hair samples for drugs like what should I do