Marijuana Detection Times and Urine Drug Tests

WSJ Team March 31, 2011 24

Before you begin to read this article it is essential you understand the amount of variability involved in this subject. The factors that can affect this, ranges from a person’s diet, metabolism, stress, to the amount and potency of marijuana ingested.

Luckily, I found a great article that answered a tremendous amount of my own questions on the subject, and my own testing gave me even more insight I can share with you.

From the California NORML page I found a great write up.  But before we dive into my findings its best you understand the drug tests that you will probably be taking in the near future. Most urine tests that are administered test for a marijuana by-product called THC-COOH. This is a non-psychoactive chemical that does not make you high but merely exists in your body after your body has broken down the THC you have used.

The urine tests that do exist are called the immunoassay test and the gas chromatography and mass spectrometry test. The main difference between these two tests is the GC/MS is much more sensitive then the immunoassay test and is more accurate and the immunoassay test tends to turn up more false positives because of its sensitivity to non-steroidal anti-inflammatory drugs.

Many tests have certain fail-safes so that people cannot cheat on them. They test for the levels of creatinine in your urine to check if it is diluted. They also check for certain additives that can be applied to urine that can mask a positive result. Some tests also test for the temperature of your urine to make sure it is not a substitute.

Last but not least different tests check for different levels of THC-COOH in your urine. It can range from 15-50 ng (nanograms). The higher the level the easier it will be to pass a drug test.

I have personally smoked 6 days before a test with a 20 ng threshold and have passed but I was clean before I smoked and I had a little less than a bowl pack. I have also smoked 5 grams on one day, .75 grams on the next day, and .5 grams the next day, and barely passed a home drug test 7 days later that tests at a 50 ng threshold. This was after working out everyday (I ran about 5 miles a day). I am about 140 pounds and am pretty fit with a quick metabolism so I can metabolize the by-product pretty quickly.

From the NORML website I found these very informative graphs.

This particular graph show the urine THC-COOH levels of 4 users who were clean before they smoked 1 marijuana cigarette. The person who ingested the Oral dose had a very potent brownie.


This particular graph shows how long it takes for regular marijuana users to test negative on a drug test.

This last graph shows how long it takes for chronic marijuana users to test negative as well.

Marijuana can stay in your system from literally 3-50 days depending on how much you smoke and all of the factors I spoke about earlier. It is important to know when you are going to get tested and prepare accordingly.

I have to give a special thanks to the people who work on the California NORML page; they have helped me out a lot in my own drug testing endeavors and the website is really worth visiting.

Lastly, this program that you find on the internet is a huge farce and is COMPLETE BS. It is called, Online THC Calculator, it is not accurate at all and is only there to scare people into buying detox product you can find it here if you want to play with.

If you want to know how we would recommend you detox you can visit our article here.


The Weed Street Journal


  1. Kris May 13, 2011 at 12:31 AM - Reply

    My Thc-cooh levels were at 1919ng. I can’t find numbers higher than 1111ng on the web. What does this mean?

  2. Duncan December 15, 2011 at 8:46 PM - Reply

    You were smoking very potent weed regularly!!!!

  3. solid smoke December 25, 2011 at 5:05 AM - Reply

    Highly descriptive blog, I liked that bit. Will there be a part 2?

  4. aimie February 16, 2013 at 11:35 PM - Reply

    An organic combination to clean your system that I know works in case of urine tests is Sonne’s #7 and #9…one is fiber and the other a detox. You have to stop smoking before you test for say, four days, and you drink this with juice in the morning and evening. It is proven to work…I’ve tried it and was very happy with it. And it’s even better that it is organic. But if you smoke while you do it, it does not work. You can order it directly from their website or get it from a health food store…about $50.

  5. How To Pass A Urine Test March 4, 2013 at 11:50 PM - Reply

    Wow that was unusual. I just wrote an incredibly long comment
    but after I clicked submit my comment didn’t appear. Grrrr… well I’m
    not writing all that over again. Anyways, just wanted to say excellent blog!

  6. big peezy March 30, 2013 at 2:03 PM - Reply

    Great information– I was particularly concerned about how Oral ingestion affects tests differently, and it appears that my waiting over weeks since ingestion of a brownie will be more than safe to pass!

  7. Joseph C Hill September 17, 2013 at 11:40 AM - Reply

    I am a a man in excelent physical shape and weigh 151 lbs and am 6′ tall and I would like to know as soon as possible how much Sonne#7 (by whhat measure)I would have to consume and in what amount of time as a marijuana user including cleantime. I would need before the actual take the drug test.

    • WSJ Team September 18, 2013 at 11:18 AM - Reply

      Hi Joseph,
      The directions on the packaging recommend:

      “Amount of dose: For average adult 1 tablespoonful. For others 1 teaspoonful for each 50 lbs body weight. Take 2 doses per day. The first one in warm water upon rising; the other undiluted at time of evening meal. However, drink at least one glassful of water between meals to assist elimination of acid and toxic waste through the kidneys. May be taken for a duration as long as desired.”

      Hope this helps!
      -WSJ Team-

  8. Peanut February 26, 2014 at 2:09 PM - Reply

    If only an occasional smoker and have taken 3 puffs but out of a pipe. What is the quickest to be clean. Or am I clean already considering it was just one or two puffs. First time in many months?

  9. Peanut February 26, 2014 at 2:13 PM - Reply

    If only an occasional smoker and have taken 3 puffs but out of a pipe. What is the quickest to be clean. Or am I clean already considering it was just one or two puffs. First time in many months? Only use for pain when out of my prescribed meds. Have lab work I have to have done and if tested positive for THC the doctor will no longer see me. Have a home test to use before going in. Is it reliable if they test it by bloodwork or urine test?

  10. Bitch Boy October 13, 2014 at 12:45 PM - Reply

    I’ve been reading a lot about a recent study by the National Drug Court Institute. The study’s conclusions are that the detection window for THC in urine is far less than what we’ve been told. The whole “you need 30 days” thing was put out there after a lot of studies in the 80’s when drug testing wasn’t as specific as it is now. According to their research, now that piss tests only look for specific canibinoids, it would be unusual for the occasional smoker to test positive after 4-5 days, and even heavy users should test clean after a couple of weeks (obviously body fat and hydration are variables here). Has anyone else seen this around? It’s obviously a legit study.

  11. Tara February 27, 2015 at 6:17 PM - Reply

    I have been a long time smoker for many,many years.. I have went to court to get custody of my niece that has been severely abused by herion addicted parents & tested positive to thc. I went to my dr @ 27days clean & still was positive so she sent it to the lab for me. I came back positive at 15ng & have to be at 10ng on day 51 so can anyone please tell me if I will be ok bc I have been told I will be thrown in jail if I test positive again.. Please help!

  12. Luke August 18, 2015 at 7:37 PM - Reply

    I smoked weed Saturday. Took a drug test Tuesday, Did I fail my test. I was not a heavy smoker and I did swear and drink a lot of water. ( we also smoked three blunts, with 6 people In rotation).
    Someone please help me!

  13. Luke August 18, 2015 at 7:38 PM - Reply


  14. Rich November 24, 2015 at 3:05 AM - Reply

    My thc level was 437.7. Is this high I’m not sure how it is rated?

    • Tony January 28, 2017 at 11:54 AM - Reply

      Insanely high lol

  15. Thomas March 21, 2016 at 11:00 PM - Reply

    I was recently informed I failed a drug yes for a job and was told if I can get my levels down to 15 they will re hire me with counseling….my levels were in the 200s…..I haven’t smoked in a week and have drank plenty of water……how long will it take to get to the 15ng…??????

  16. Mason April 10, 2016 at 11:04 PM - Reply

    I smoked half a joint 3 consecutive days 21 days before my test coming up. Im 23 and healthy individual. Would i be a good chance of passing a lab test?

  17. shane smith August 31, 2016 at 1:29 PM - Reply

    the verdant detox kit ( ) was voted most reliable in 2015 by high times magazine. i’ve personally used it twice to pass pre-employment drug test, on short notice too. idk, if yall are looking for something then check it out

  18. Kelly September 29, 2016 at 10:07 AM - Reply

    Hello I was tested for thc and didn’t smoke much just here n there occasionally n they sent it off to the lab it came back 11ng is that high or very low anyways it was a blood test not urine so was it almost out of me i really need a answer please tell me cause there trying to give me a suitable for ot being that low least I think it low help me please with a answer to my question. Thank you for ur help of ur able to answer me

  19. Jimmy1 November 11, 2016 at 6:54 PM - Reply

    When does thc show up in urine after toking

  20. Brian February 23, 2017 at 2:36 PM - Reply

    I took two hits of strong weed from a pipe at about 6:00 PM on a Sunday and had to produce urine for a drug test at 10:00 AM the next morning (I was not expecting the test). I hadn’t smoked for the previous 2 months or so. I am 5′-8″, weigh 180 # and have a decent amount of belly fat. I am not particularly active although I do walk my dog multiple times every day. The results were negative. The only thing I did to detox was drink two cups of “Everyday Detox” herbal tea with lemon juice and drank a couple of 8 oz glasses of cran-grape juice.

  21. mary parrott May 14, 2017 at 3:38 PM - Reply

    how long does it take for the percentage of thc start to drop after you stop using? i got piss tested on the 27th of april, the percentage was at 52 percent, i didn’t stop using untill may1st, then they piss test me again on may 11th it has to be under 52 percent, should i be worried?

  22. Ann July 31, 2017 at 2:37 AM - Reply

    Im asking a question for a friend in prison. He has to do a mandatory drug program to be released as early as possible. He got kicked out because failed drug test for thc. Those of u unaware u can get anthing in prison drug wise…tho he swears he hasn’t used since incarcerated 74 days ago.. He was a heavy user of highgrade stuff is 5’6 160 pounds. He asked me to research what his levels could of been before he talks to his councelor so he goes in with correct knowledge to argue was before his sentence..

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