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.
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    (continued) also i am 120lbs female

  • Andrea

    Help.! I’m 5’6 around 210 lbs. I don’t smoke much. I had a urine test this morning. I drank certo last night and also about a month ago since I thought they were gonna test me that time. Last time I smoked was June 13. About 2 bowls or a bit less than that. The time before that would probably have to be early May just a couple of hits. Will I test positive?! I’m shitting bricks over this.!

    • Xacto

      You should easily pass, based on your information.

  • toolezbionic

    Hey there. I am 5’5”, about 190lbs and I smoked about 3-4 times in the last couple of weeks. Probably a stupid move since i am desperately trying to find a job. I didn’t know that just about every job I want to apply for states that they do pre-employment drug testing. I need a job REALLY SOON (friends of mine wanted me to rent a house with them, and it’s happening a lot sooner than I expected), so now I am getting panic attacks because I am afraid this going to keep me from getting hired. The last time I smoked was two days ago and took about 4 hits from a bowl. I don’t smoke more than once a day and before these last couple of weeks I hadn’t smoked for a month or two (I pretty much just do it when I am hanging out with my sister). That’s probably considered occasional, right?

    So, by the time I get a call back, an interview, and wait for them to connect with my previous employers, do you think I would pass? Do they test at the start of training? What can I do to help this along? I know about drinking more water and exercise, but is there anything else around the house that would help? I know that lemon juice and other things with lots of citric acid clear out your system of some things, but does that include marijuana?

    Sorry, I am just really freaking.

    • Xacto

      Go to a local drugstore or Target and get a THC test $20 or $30. It will give you a good idea. Do it before you go for your drug test.

  • Xacto

    I will provide an honest and accurate account of my experience with THC metabolite testing. About 5 posts down I described my usage and physical characteristics. I have been experimenting with detection times in my own body, using a THC cartridge test from a reputable drug test supplier in PA. I got a box of THC test cartridges for about 90 cents each. These are DOT approved testing devices and are very reliable for 50 ng THC detection. My experiment has been quite enlightening. When I am completely clean of THC, if I smoke two hits of good quality ganja one time, I personally will pass the test later the next day, with normal hydration. On the day I smoke, I fail the test within one hour of smoking and for that whole day. If you are fat, you may fail for longer because THC is fat soluable. My experiment has been ongoing, and I will share my most recent results. I have been smoking for almost two months, every day, two or three times per day, two hits per session average. Before this period of smoking, I was completely clean. I have a body mass index of 24, normal weight. I stopped smoking completely 4 days ago and began testing at day 3 (yesterday). Here are my results. Day 3 after no smoking, at noon = negative (pass) Day 3 at 3:00 pm = positive (fail), Day 3 at 6:00 pm = pass. Day 4, today at 8:00 am – first urination = fail, Day 4 at 10:30 am 3rd urination = pass. Day 4 at noon = pass. My conclusion is as follows. An individual like myself can pass the 50 ng of THC test after 3 days of abstinence from smoking, but can also test positive depending on hydration, diet, and activity level. Dilution of urine through water intake can be effective in aiding the process of avoiding detection. I did not dilute for this experiment. I ate normally and had low activity levels for these tests. Some basic principals of THC presence in urine seem to be: How much you use, when you last used it, how fat you are (if you are reading this in the USA you are probably fat). A healthy male or female who was previously clean for 30 days, with a BMI of 25 or less will probably test clean from one time usage (3 hits) after 2 days of not smoking, provided they are normally hydrated. Drugstore test kits are expensive, but may give you peace of mind. If you want to experiment with your own detection times, I strongly encourage everyone to purchase inexpensive THC test cartridges online. Just Google (THC Test Strips). The prices are better because you buy in bulk. Share you results, but you must be scientific and honest. Otherwise you may skew the body of knowledge on this subject. Best wishes to all. Smoke smartly…

  • Xacto


  • zindie

    im 245 pounds and i took three hits how long will weed stay in my system last time i smoked was Wednesday 23rd of July?

    • Jessenia

      From what i heard a while. Since you are on the heavier end of the spectrum. It will take a long long time to leave your system

  • angel

    So I’m 5’2 & I weigh 130-135, i have a urine test Monday & that’ll make 19 days since I last smoked, before that it had been a couple months. Will I pass it?

    • andrew.shafe

      Yea most likely

  • Anthony

    Please help i smoked 3 times in the last 3 days im 5’7 and weigh 130 will thc be out of my system by november PLEASE HELP

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  • shelby

    Ok so I’m 5’1 and I weigh 105. I smoked basically everyday for a year. I quit smoking 6 weeks ago. I have to take a drug test for my nursing program at college. About how much longer until I should be completely clean?

  • Brian


    I smoked on June 5, and July 5 for the only times in my life. I had a drug test on July 24. I should be clean below a 50ng/mL test correct?

    • JoJo

      Basically in the same boat as me. Hopefully we are good. I’ll know this week.

    • Brian

      I would greatly appreciate a response from someone who knows what they are talking about.

      • JoJo

        Dont be a little prick, bitch.

  • JoJo

    Hey everyone. I would consider myself a moderate smoker, as in only on the weekends. I’m 6’3 and weigh 170. I’m tall and skinny. The last time I smoked was on the fourth of July. I had a drug test on Wednesday about 17 days after I smoked. I starved my self and drank only green tea and water the whole day. I only gave a mid streams ample. Please give me some re assurance that I passed! :/

  • Hollster

    Will two hits generally show up in a hair test?

  • Stupid

    5’10 about a190 pounds. Last smoked a bowl about three weeks ago. Drug test tomorrow. Any possibility I’ll pass?

  • Adeeezy

    Hello, I am 5’10 and weigh 268lbs , I am active (workout 3 days a week) & the last time I smoked was 2 weeks ago ( 2/3 hits from a bowl) however before that I was a moderate/ heavy user ( I smoked 2 times a day, half a blunt every session) and did this for 5 months now, if I take any of the three drug tests, will I pass?

    What if i get a medical card, can i work with that as my excuse?

  • Neisha

    Hi, I’m 5’4 5’5 and about 135lb. I last smoked about 2 weeks ago & I have a drug test within the next week. Will I pass if I was a moderate user? I’d say I probably smoked for about a month probably ever 2 days 2 blunts whenever I did smoke.

  • bri

    So I smoked 4 days in a row. 1/2 blunt each time, otherwise i never smoke. Im 5’4 175, had a UA today..urine and blood. 18 days later, will I pass?

    • Mark

      it is possible, will be close. Do you smoke often? or is this a one time splurge?

      • bri

        One time splurge. Vacation.

  • GeraldDull

    Okay, so. I’m 6’2, weigh about 240lbs.

    I stopped smoking last January after being an everyday smoker for roughly 4 years. I then began smoking again everyday mid-April.

    I stopped again around June 1st, and began testing clean about 2.5 weeks into stopping.

    On July 17-21, I visited Colorado. My friend is a huge pot head. I probably smoked a gram of medicinal, did 8 DABS or so, and ate 10 THC candies totaling 100mg of THC.

    My drug test is going to be towards the end of August, like the very end.

    I’ve been drinking a lot of water, cranberry juice, taking Niacin, and I also bought one of the 20oz Maximum Strength Ultimate Gold Detox drinks while I was in Colorado. I have many at home tests too, so I’ll be monitoring it.

    What do you guys think my chances are?

  • Anonymous

    Hello. Used for chronic pain. Was quite a bit but in less than two weeks of time. It’s been about 21 days now and was urine tested today. I’m 147lbs approximately and not a usual user. Was only a splurge during honeymoon.
    Will I pass