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

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.
  • Nikki

    So if I smoke smoking now. After 12 hours it will be negative

  • Nikki

    So if I stop smoking now. After 12 hours will ppl it be negative In my salvia

  • Nicole

    How long does weed stay in your blood stream? I’ve got to get some blood work done next week & I’m a little skeptical about it showing up.

  • Tess

    I smoke a gram in like 5-7 days haven’t smoked for 5 days and have been drinking so much water I pee probably twice every hour do u think I will test positive?

  • Netty

    I took a big hit about 4 days ago after not smoking for 2 years, I’m 5″2 will it still be in my system right now?

    • jro

      Ur good I passed my test today I smoked some fire six days ago just drink a lot of water or beer haha workd for me

  • bob

    If I smoked like 4 days ago will I be able to donate blood tomorrow ? Lol just wanna know

    • tristin

      They don’t drug test your piss

  • maddy

    I haven’t smoked in like 3-4 weeks, before that I hadn’t smoked for over a month- if I smoke a blunt tonight, how long will it take to leave my system?

  • Madi

    I’m about 5’6″ and weigh around 110-115… i’ve been smoking daily (about 1.3-1.5 grams a week) for like 2 years. I dance so i’m decently active. How long will it stay in my system? I’m looking to get a job and I’m taking a medical lab class where we learn how to do a urinalysis, so we also take one. I’m just curious as to how long I should quit smoking and how long it’ll stay in my system.

  • help

    I think I’m just being paranoid but the last time i smoked was the first or second weekend in October. I have to take a drug test the end of this month. Will i be able to pass it?

    • Unknownlol

      Yes you will but it depends on how high or how much hits you got…im afraid im bout to get busted with a drug test too lol! i did it for the first time in 4 months and got high as fuck.

  • Ashley

    I smoked about 4 times last month Sept. 29 , Oct. 4&5 , then on the 8th. I just took a drug test on Nov. 7 , for pre employment. Do I have any chance of passing ? I weigh roughly 130 . I rarely smoke now so I’d say I’m a moderate user

    • Ashley

      I passed the test and got the job
      So hopefully this will help someone out in the same circumstances.

  • Please Help

    I smoked tonight for the first time since around July, but I only took 3 hits. My school does hair testing, and if I get tested will I get caught, or is it likely that since I don’t smoke and only took 3 hits that the THC won’t stick to my hair follicles?

  • Dominick

    I smoke once a day but I drink 3 water bottles a day to…Am I more likely to get caught

  • Joe

    I smoked 3 times this summer. I recently smoked two weekends in a row only getting high once. Taking a few hits each time. I’m a college football player and got tested today by the NCAA which is a lab test. I passed a CVS bought test but still am scared. Am I good? It’s been 9 days since I’ve smoked and I workout a lot and obviously practice every day

  • Amy

    I had a few hits and may have a piss test in 5 or 6 days, I weigh 145 and im 5’6. Will I be ok? It was only my second time smoking in my life and both times were far months (almost a year) apart.

    • william head

      no the cops will come over and shoot you
      rest in peace

  • Jon

    I’ve smoked 5 times in the past 3 weeks, it was usually just 1 joint/blunt each time, I have 2 in a half weeks before a drug test, Will I be clean?

    • joe

      Naw dude you’re f**ked

    • Father Cannabis

      Stopping now staying hydrated and exercise enough to sweat profusely will help move the thc out of your system. This will help diminish some but NOT all of it. Cranberry juice helps also. Start taking b12 vitamins several days before your test and a little extra the night before. Then several hours before your test start drinking plenty of water being sure NOT to intake it all at once. About two 32 ounce glasses. This thins out the toxins in your urine thusly the reason for the necessity of added b12. If your urine is to watery it throws up a “red flag” at the test facility. Best of luck and God bless you. Of course take any information as a suggestion only. because if you aren’t white THEY already think your guilty. And PRAY that soon people dieing of incurable diseases will be able to have access to medical marijuana. Then roll me a fat one too!!! AMEN

    • okrllyy

      Ehhh you miiight squeek by

  • Kyle

    I am 122 IB and have a test tomorrow and it’s been since the 31st will it show up in a urine test??? Need answers fast

    • okrlly

      How often did you smoke? If it’s a urine test, buy the drink. It works if you follow directions.

      • Kyle

        I rarely do smoke and what drink

  • penelope

    I smoked twice (both time hits only ) in October. The last time was mid October. I have a wiz quiz in 3 days, I’m 5’5 and 115 lbs. Am I gonna pass this?

  • Frankenstein


    quick facts: I’m 22, 5’9 and weigh 199, but I’m going to have to be going down to about 185 soon to make weight.

    So I’m a frequent smoker. I’ve smoked pretty much every day for the past… Year? Or something like that. I’m not entirely sure when my urine test is, but it’s soon. If I stop now and keep active/drink plenty of water when should I expect to be completely clean? I’ll buy the drink and do the b12 stuff too. I know the chart says 15 days, but is that entirely accurate? And if so, what can I do to pick up the pace?

  • Rey

    I weigh 200 pounds. I smoked about a blunt a day October 15-18 and I have a test to take by Monday which will make it almost a month. Will I be ok? It’s a urine test and before that I smoke sporadically on weekends nothing major.