Jan 052013
 January 5, 2013

marijuana weed drug testing system saliva hair urineThe data used to create this infographic is gathered from research on drug testing methods and the information presented by drug screen manufacturers. Some resources include Redwood ToxicologyCannabis Drug Testing,California NORML. The information presented is only a guide or estimate since drug testing has many variables that can influence a positive or negative outcome.

How Long Does Marijuana Stay in your System? is the most frequently asked question that we receive at HomeHealthTesting.com. While there is no definitive answer, we have presented some guidelines. The only way to really know if you are positive is to test yourself. You can test yourself with a cheap drug test and know if you are positive. Buy a THC urine drug test

How long does THC stay in your system?

The most common drug tests used are urine, saliva and hair. Each test has a different detection time which is important to know. The urine drug test is the most commonly used because it is cheap and has a longer detection time than a saliva test. There are several very important factors that can influence how long THC will be present in your urine:

  • Weight
  • Body Fat
  • Amount Used
  • Frequency of Use

Since these factors will vary greatly for each individual, there are no definitive guidelines to tell you how long you can test positive for THC.

On a Urine Drug Test, THC will appear as a positive within 2-5 hours of use. How long it will still show on a urine drug test is estimated based on frequency of use, but does not take into account the weight and body fat of the marijuana user:

  • One Time User may show positive for 1-6 days
  • Moderate User may show positive for 7-13 days
  • Frequent User may show positive for 15 or more days
  • Heavy User may show positive for 30 or more days
  • Some Heavy Pot Smokers have reported being positive 45-90 days after quitting

On a Saliva Drug Test, THC will test positive within one hour of use, but may only show positive for about 12 hours after last use.

On a Hair Drug Test, THC will show up about 7 days after use and most hair drug tests will test for a 90 day period. However, THC does not always bind to the hair follicle which makes it not always considered an accurate testing method for marijuana use.

The most reliable way to know if you are testing positive for marijuana use is to drug test yourself.

how long does weed stay in your system
By: HomeHealthTesting.com

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About Johnny Green

Johnny Green is a marijuana activist from Oregon. He has a Bachelor's Degree in Public Policy. Follow Johnny Green on Facebook and Twitter. Also, feel free to email any concerns.
  • Butter lover

    Hi everyone I am new to this forum I was wondering of I can get some advice or help. I currently am looking for work and received a call for a great job opportunity, they do drug testing . I smoked a joint last Wednesday being the 8th of this month ,not the whole thing though but a few hits and one joint I took a couple hits from a before that, I shouldn’t of but my craving for it was really bugging . My job interview is next Monday the 20th , what will it take for me to pass that drug test? Might it still be in my system , I have been working out often and I weigh 135 and I’m 5.6 in height . Help pleeeasse ;))

  • billycheesesteak

    So uhhm I smoked about half an ounce. Havent smoked in a year prior to that and this half an ounce was smoked in a 48 hour time period lol. Yeah crazy weekend. I just wanna know how long it might be in my system. On probation but ive been on it for two years now and haven’t been tested once. Im not really worried im just curious

    • stonerchliches420

      Half an ounce is a shitload dude… I’ve been smoking for three years now, but had to quit for random testing on 2yr Probation. (Just got ordered to drop) I’d say, your looking at, at least, three to four weeks. Half an O would last me a fucking week bro.

      • Josh

        It will probably last me a weekend

      • Jay2the

        Damn I’m seriously behind I had mine now for 11 days smoke 5 sweets a day… ( seriously lacking on my pot-head ism)

  • Lisa

    I hit a joint one time two months ago and had a hair follicle test today will I fail it? I haven’t smoked for several years and I only hit it once and haven’t smoked since.

    • Jay2the

      Well Lisa what happened

  • Ron

    I used to smoke all the time categorized as a heavy smoker. I quit for e military and went. 5 months with no smoke. I recently smoked 3 times in one week due to delays. How long do you think it will take to pass a drug test if one comes my way?

  • 619rasta

    Ok im 105 and 5.8ft. I have been clean for a year now. And im planing to smoke about 3 grams in 2 weeks straight and have 3 months clean before i join the navy. So would that work for me?

    • Kelli

      Yes. It only takes 30 days to get clean. 3 months you’ll have newborn piss. Lol

  • sarah

    okay so i weigh 120 and I’m 5’6′ and i need to my hair and blood for my next doctor appoint and i haven’t smoked in maybe a month now? so i wanted to know if I’m good now?

  • danielle

    I am 17 years old, 5’7 and I weigh 135. I smoked kush resin from a friends pipe. I haven’t smoked in almost 1 year. My metabolism is high. I didn’t even get high at all, or even inhaled it that much at all. I smoked 1 week ago, I had to take a drug test yesterday for a job.

  • Surething39

    It’s so funny because everyone on here that is worried about testing is so BECAUSE they have a job, are in the military, etc…I hate how people believe it’s impossible to be responsible, perform your job well, or be an upstanding member of society just because you smoke. Other things should be taken into more consideration.

  • jmkfromthe419

    new job is testing hair, haven’t smoked in 3 wks and drink a shit load of water, will I pass?

    • Kelli

      Sorry but you will NOT pass a hair test. I’m 100% sure. It’s so accurate they’ll know it’s been 3 weeks since you smoked. Water does nothing because marijuana is fat soluble, not water soluble like every other drug which is why it takes the longest to get clean. Water only helps the day of a urine test because it dilutes your levels.

  • tammy


  • jeff j

    got a question for yall I went to pain clinic on the sixth of oct. soon as I got home I started drinking and smoking see my bday was comin up and I was depressed about turnin 44 I smoked bout 7 o 8 joints between the 6th and 14th when I stopped im a casual smoker maybe 3 a month but my problem is I got a doc apt on the 10th of nov almaost 3 weeks away I need to know how to get the weed out my system but keep my norcos in couse I know hes gonna test me I weigh bout 200 pounds and am almost 5 ft tall and female some PLEASEEEEEE HELPPPPP MEEEEE

    • Kelli

      I’m 5’4 & 110 lbs. I only need 20 days. For your size id say either you eat a lot or have slow metabolism. 1. Do cardio. Sweat, sweat, sweat it out. 2. Get some natural apple cigar vinegar like pictured below from whole foods, take a teaspoon a day to burn fat & boost metabolism. You want to burn the fat contaminated with THC. Weed is fat soluble, not water soluble like other drugs. THC is stored in your lipid / bile fat cells. 3. Store more fat, new clean fat. So eat good. Do NOT work out the last 3 days prior to test. Eat & be lazy.

  • colin

    im 5″10 150 lbs. I’m on probation and I get tested once a month right now. I’m clean right now & havnt smoked in a month and a half but I wanna smoke again after my next test. if I smoke on the weekends or maybe 1-4 times for one week out of the month would I pass a test? that would give me about 3 weeks to get clean but I don’t want to mess up & fail

    • Kelly

      Yes you’ll pass. I’m 5’4 and 110 lbs. I always smoke after my probation drug test and the next 4 days. It takes me 20 days to get clean. 22 days at most. My best friend is short and fat & does the same thing & that’s the person who made me feel comfortable doing it.

    • Kelly

      And I smoke only the best high grade weed. That Cali shit. 3 blunts a day by myself. Before this probation crap my tolerance was extremely high so it takes a lot to get me high.

  • lex

    So I was a frequent smoker smoked about 3 times a day for a while but haven’t smoked in 21 days. Got a drug test coming up at a local major hospital and I’m very worried. I NEED this job. What do you guys think so I have a shot at passing?

  • lex

    I weight about 143 pounds and I’m 5″7

  • John

    I’m 107 pounds and I was 1 month and a week clean then I smoked a few bowls . I am now 2 weeks and 1 day clean and I’ve been running miles with my judo club . I’ve been drinking a lot of water. Will I pass?

    • Kelli

      I’m your size & smoke heavily for 4-5 days after probation drug test. I use to fail after 2 weeks clean but now I know it takes me 20 days to get clean so Idk if 15 days will do. Get yourself a home drug test. You may be ok. I never work out and can’t even run a quarter of a mile so you’ve got that on your side.

  • Annoyed

    I’m 6ft 2, about 200 pounds, but athletic build, i have not a lot of fat. I didn’t smoke for quite some time ( maybe a few weeks), then smoked maybe once a day for four days. Now i haven’t smoked for about 16 days, i have a urine drug test in two days. Will i pass?

    • Leeken lee

      Yeah. No worries

  • Gg

    I haven’t smoked in 4 months, if I smoke a gram this weekend, how long will it stay in my system??

    • Chayes112

      It should stay only 1-4 days if you have a high metabolism and low body fat, drink a lot of water and don’t be afraid to go out and sweat, I smoked Friday the October 17th and passed a drug screen I had taken today the 22nd, I drink lots of water have low body fat and sweat at work, if you have a slower metabolism, and more body fat it will stay up to 6 days if I’m right, but I would only smoke one blunt or joint to be on the safe side, if you do that, you will be clean by next week around Wednesday.

      • ShinJen

        hey dude i smoked last month on the 27th about 4 grams of weed with my buddies. I havent touched weed until now and ill be having a urine test in 1 – 2 weeks time. I have high metabolism, 57 kg, 5’8, sweats a lot and has been drinking a lot of water. Am i good ?

  • FunkyWeed

    So have a drug test today. I was smoking heavy up till about a month ago. Then I started smoking only on the weekends. I stopped completely about 2 weeks back. I hit the bowl twice on Saturday night and a full bowl (mini bowl) on Sunday morning. Today is Wednesday, since then, I have drank a shit ton of water and hit the sauna Sunday night, Monday, and Tuesday. Think I will pass?

    • Lee lee

      No you won’t. Sorry.

  • mapanggulo

    If a teenager tried marijuana for the first time, said she tried a pinch…would it still register in her system?? I’m just wondering if I tested her now that if would fail the UA – a parent against marijuana use/legalization

    • Timmy

      Your daughters prolly popping pills and having sex all the time. Weed should be the least of your concern

      • mapanggulo

        Since weed is what she got suspended for it is my concern. That is the reason why I asked the question you neglected to answer.

        • Bob

          It will still register

          • mapanggulo

            Thank you sir!


      It depends on her weight, activity level,and frequency of use. If it was a “pinch” as she says I’m not sure if it would show up. I’ve been through this with my daughter and her metabolism processes it fast.. If I don’t catch her within a week of doing it it doesn’t show up..
      I’m not sure why you got response you did initially but in one aspect I agree… I would so at least a 5 panel test to see if she has used or experimented with prescription drugs. Comments about her sexual activity aren’t appropriate and are plain rude. I apologize that someone is nasty enough to post it ..especially since you asked a real question and based on your concern and caring for your daughter.

  • Tilly

    Hello all, I havent smoked in almost like 3-4 years and smoked a gram about two – three weeks ago and was wondering if itd still be in my system im like 125lbs and 6’1 and have a very high metabolism. If I take a drug test today will I pass?

  • kev

    I’ve been smoking daily for the past 2-3 years. Maybe about 3 joints or so a day. I weigh a little under 120, and I’m 5’7″. Is there an estimate as to how long it would take to get out of my system? Even if I started exercising and flushing?

    • Andy

      you have atleast have 2-3 1/2 months. Dont forget that your lunges collect the resin and can still be in your system for a while… Been toking since middle school and still going 8 years later.

  • Kathy

    How if i’m smoking about 2 joint and add up with some others drug (merhadone-2 & ecstacy-3) and alcohol too. It’s about 3 days ago. Will i pass the test? I’m getting confuse how to calculate my day to be clean when everything been mix up

    • N

      Methadone has a LONG half life ..it’s stays in your system a long time the others I don’t know.

  • Brooklyn

    What is my frequency if I smoke only every other week?

  • kenny7070

    if i smoke tomorrow and i havent smoked in 3 weeks how long will it last?

  • stunna

    I smoked half a blunt in two month. Will I test positive?

  • Marie

    I have smoked 4 the last 7 years every day nuthin but kush now have stoped for like 3 months i went out last Friday and smoked 2 blunts i have a drug test the 4th of nxt month i hope im gonna pass ima try to find a detox drink or sumthing maybe it will work

  • Marie

    And does anybody kno hw lng perks stay in ur blood

  • AGod

    I just passed a dollar store drug test after 2 days of not smoking. I’ve smoked nearly everyday for the past 3 years. I am not sure how to interpret this.

  • spryfrizzle

    I smoke 3.5 grams a week. I quit smoking 8 days before my test. I sweat a lot at work (kitchen, haha who doesn’t smoke in a kitchen). I weigh about 200 and 6′ tall. I drink about 2.5 liters of water a day. Will i pass?

  • THC KT

    How long would it take to get out of my pee if im 5’1 100 pounds an havent smoked in a week or two