Two Puffs Too Bad: Demystifying Marijuana Urine Testing

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MJ, a 40 years old female, presents to  your pain clinic for a  routine follow-up visit. You decide to run a random urine drug screen by immunoassay (IA) and she tests positive for cannabinoids.

When asked, MJ admits “I only smoked two puffs five days ago”.

Fact or Myth?

Mena Raouf, a star PharmD Candidate,  took a closer look at this.
Here’s what he had to say…


Marijuana Pharmacokinetics

Δ9-tetrahydrocannabinol (THC) is the major psychoactive metabolite of cannabinoids, which is highly lipophilic and distributes into adipose tissue, liver, lung, and spleen. [1,3] Following inhalation, THC can be detected in the bloodJeff chemistry bow tie within seconds; however, its bioavailability varies depending on the depth and duration of inhalation. It is estimated that the bioavailability of THC is approximately 10-14% in occasional users and 23-27% in chronic users. [1,2]

As seen in figure 1 below, the psychoactive component (THC) of marijuana, undergoes hepatic hydroxylation to generate the equipotent metabolite Δ9_tetra hydrocannabinol (11-OH-THC) catalyzed by CYP 2C19 and 8β-hydroxy-Δ9-tetrahydrocannabinol (8 β -OH-THC) catalyzed by CYP 3A4. [1,3]  11-OH-THC undergoes oxidation to generate the inactive carboxy-Δ9-tetrahydrocannbinol (THCCOOH). Carboxy-Δ9-tetrahydrocannbinol is conjugated with glucuronic acid and excreted in the urine. 8β-OH-THC undergoes dehydroxylation to generate 8β,11-di-OH-THC, which indicates recent cannabinoid use if present. [1,3,4,5]    However, carboxy-Δ9-tetrahydrocannbinol is the most abundant and prevalent metabolite and is ultimately the compound of interest for urine drug screening. [1,3,5]

Figure 1: Metabolism of THC Following Smoking
THH chemistry schematic_PP fig-1_BMP








Urine Detection

Figure 2 illustrates how THC and its metabolites are eliminated in the urine and feces as shown in a study by Manno et al. [8] where cannabinoids were measured in the urine in 8 subjects that smoked a marijuana cigarette containing 27mg of THC.  THC urine concentrations peaked at 21.5 ng/mL in 2 hours  and were undetectable (<1.5 ng/mL) in 5 out of 8 subjects after 6 hours. Urine concentrations of 11-OH-THC and THC-COOH peaked at 3 hours and 4 hours respectively.  THC-COOH, the compound of interest in urine drug screening, has a urinary half-life of 2-3 days. [5,6,8,10]

Figure 2: concentrations of THC metabolites in the urine following smoking [1,8]
THH chemistry schematic_PP fig-2_BMP

Following a single marijuana use, THC is unlikely to be detected in the urine beyond 3 days at the 50 ng/ml cut-off level and beyond 7 days for the 20 ng/mL cutoff level. [4] For a single use based on the 50ng/mL cutoff, carboxy-Δ9-tetrahydrocannbinol can be detected in the urine within 3 days. For moderate use (4 times/week), the detection winodw is  5-7 days. For daily use, the detection window is 10-15 days with up to 30 days for long-term chronic smokers. [9] Detection times are summarized below in table 1.

Table 1: Marijuana Urine Detection (IA) Time Based on Use [7]

Frequency of use Detection window (days)
Single use 3 days
Moderate use (4 times/week) 5-7 days
Daily use 10-15 days
Chronic heavy use >30 days

Now back to our patient MJ

If the patient truly smoked “2 puffs 5 days ago”, then she should have tested negative based on the 50 ng/mL laboratory cut-off by immunoassay. Her positive test at this cut-off translates to moderate use (4 times/week).

Marijuana is still the most commonly detected substance of abuse on urine drug screening by IA, but let’s not forget that false positives are common with cannabinoids as elucidated and identified in Dr. Fudin’s Urintel Drug Application after inputting concomitant medication data.  It remains a dilemma in pain management where patients with true pathologies and legitimate pain seek marijuana and other illicit substances for pain relief and anxiolytic effects. The presence of illicit substance does not necessarily negate the legitimacy of the patient’s pain complaints, but it may suggest the presence of concurrent disorder such as substance abuse or “chemical coping”. The patient must be willing to work with the healthcare team to receive treatment for both disorders; that is a decision the patient has to make.

Mena Raouf, Pharm.D. Candidate, 2016
Mena Raouf, Pharm.D. Candidate, 2016

This article was collaboratively written with Mena Raouf, a 2016 PharmD Candidate at the Albany College of Pharmacy and HealthSciences with a concentration in Nephrology. Mena moved out of Egypt 5 years ago to start pharmacy school and career in the U.S.  He hopes to complete PGY1 and PGY2 Pharmacy Residency and practice as a clinical pharmacist specialist. He is currently under the mentorship of Dr. Fudin studying pain management.


  1. Lapoint JM. Cannabinoids. In: Hoffman RS, Howland M, Lewin NA, Nelson LS, Goldfrank LR. eds. Goldfrank’s Toxicologic Emergencies, 10e. New York, NY: McGraw-Hill; 2015.
  2. McBurney LJ, Bobbie BA, Sepp LA. GC/MS and EMIT analyses for delta 9-tetrahydrocannabinol metabolites in plasma and urine of human subjects. J Anal Toxicol. 1986;10:56–64.
  3. Grotenhermen F: Pharmacokinetics and pharmacodynamics of cannabinoids. Clin Pharmacokinet. 2003;42:327–360.CrossRef  [PubMed: 12648025]
  4. Smith-kielland A, Skuterud B, Morlan J. Urinary Excretion of 11-nor-9-Carboxy-AgTetrahydrocannabinol and Cannabinoids in Frequent and Infrequent Drug Users. Journal of Analytical Toxicology, Vol. 23, September 1999
  5. Huestis M, Mitchel JM, Cone EJ. Urinary Excretion Profiles of 11-Nor-9-Carboxy-AgTetrahydrocannabinol in Humans after Single Smoked Doses of Marijuana. Journal of Analytical Toxicology, Vol. 20, October 1996
  6. Goodwin RS, Darwin WD, Chaing N et al. Urinary Elimination of 11-Nor-9-carboxy- 9-tetrahydrocannnabinolin Cannabis Users During Continuously Monitored Abstinence. J Anal Toxicol. 2008 October ; 32(8): 562–569.
  7. Moeller KE, Lee KC, Kissack JC. Urine Drug Screening:Practical Guide for Clinicians. Mayo Clin roc. January 2008;83(1):66-76
  1. Manno JE, Manno  BR, Kemp  PM  et al.: Temporal indication of marijuana use can be estimated from plasma and urine concentrations of delta9-tetrahydrocannabinol, 11-hydroxy-delta9-tetrahydrocannabinol, and 11-nor-delta9-tetrahydrocannabinol-9-carboxylic acid. J Anal Toxicol. 2001;25:538–549
  2. Detection time of drugs of abuse in urine.Vandevenne M, Vandenbussche H, Verstraete A Acta Clin Belg. 2000 Nov-Dec; 55(6):323-33.
  3. Karschner EL, Schwilke EW, Lowe RH et al. Implications of plasma Delta9-tetrahydrocannabinol, 11-hydroxy-THC, and 11-nor-9-carboxy-THC concentrations in chronic cannabis smokers. J Anal Toxicol. 2009 Oct; 33(8):469-77.


330 thoughts on “Two Puffs Too Bad: Demystifying Marijuana Urine Testing

  1. Good day Dr. Fudin or anyone else willing to offer an informed opinion,

    I was offered a DOT regulated job on the condition I pass a screening. Split sample, 5-panel cutoff of 50ng/mL, possible confirmation by GC-MS cutoff of 15ng/mL.

    However 2 weeks ago I actually failed another unrelated 5-panel at 35ng/mL. It had been at least 3-months closer to 4 since I had ingested any THC. Full disclosure, the night before I had drank pretty hard on gin and tonics, I’m trying to keep this in check..personal belief that this is not an acceptable replacement for pot. So I was considerably dehydrated and had strong coffee prior to the test as well. I barely provided enough urine to meet the level.

    One week later after learning of the concentrated 35ng/mL result I took a rapid screen which passed the, I assume 50ng/mL cutoff. More hydrated this time.
    Prior to yesterday, in the 2 weeks since the 35ng/mL result, I’ve since exercised moderately, hydrated well, drank an ‘Herbal Clean Ultra-Eliminex’ two days prior, some sauna time, decent nutrition.

    At 16 days since the 35ng/mL, and 9 days after having passed a rapid 5-panel, yesterday morning I took the DOT pre-employment UA. Morning of, two hours prior I ate a pretty hearty breakfast, consumed considerable amounts of water, a strong espresso/cold brew, urinated a few times, then gave my sample. Even made an attempt to give only ‘mid-stream’ urine while still providing enough for the DOT split sample. The color, while pretty light wasn’t really clear.

    After 2 weeks and given the efforts I made, I went into the test pretty confident but now, for what’s riding on this, and the nature this situation while awaiting a result, I’m worrying and 2nd guessing.

    My concern is that if a possible dilute, it is summer, I’ve always been instructed to consume ample water. If creatine levels test low that it could possibly flag above the 15ng/mL cutoff on GC/MS confirmation as Dilute-Positive.

    I’m decent shape, 32 y.o., 6′ 192lbs, roughly 15-20% BMI. I’ve always been a heavy sweater, not sure if that’s indicative of a good metabolism/toxin elimination.

    Essentially I’m praying 2 weeks and a few efforts was enough to reduce a concentrated 35ng/mL sample, to a diluted <15ng/mL sample.

    Thank you for reading/offering opinions,


    1. I have been smoking for past 6 months..2 puffs in the morning and 3 puffs at night…
      stopped for 6 days then smoked for a week….then stopped for 5 days… and smoked one more time…
      since that last day i have not smoked for 10 days now…I have been drinking lots of water and tested negative in at home tests.
      Will i pass the lab test?

  2. Hi there! I have a DOT test on the 28th. I took a hit from a bowl two weeks ago, once on Friday and once on Saturday. Before that I took a few dabs about 5 weeks ago. I’ve taken 2 at home tests and both show negative (with a very faint line). I’ve even ordered a 3 day detox kit to start soon. What are my chances of passing? And will the detox kit help??

    1. Clinical lab tech here, I run these tests on a daily basis. At home kits and the ones used in hospitals and clinical labs are exactly the same in most cases, with the cutoff at 50ng/mL. Speaking from experience, using the competetive binding Immunoassay cards generally used in hospitals and at home tests, labs are required to call a negative result on an analyte whenever ANY line is seen in the test region, no matter how faint. So chances are, if the at home test was negative, the lab’s test will show negative as well. Also, according to the data above, the dabs should have been out of your system within 30-40 days, and the one bowl hit would have been below detectable levels after 3-4 days. I’d say you’re golden

  3. Hey Doc,

    May 11-14th I smoked approximately 2-2 1/2 blunts. Before this I hadn’t smoked in two years. On May 20th I was selected for a random drug test (immunoassay). I drank some certo and 3 water bottles about 45 minutes before testing. Will I test positive?

  4. I’m 5’8 175lbs and smoked quite frequently for the past couple of months I would say close to once a day. I am drinking a lot of water and exercise every day I have a body fat percent of 9% and I’ve never struggled with gaining weight so I assumed my metabolism is quite fast. I have a drug test in about 4 and a half weeks do you think I’ll be okay?

  5. Hello, I recently stopped smoking exactly 40 days to this day, I’ve taking many home drug tests at the 20ng and 2 days ago I still tested positive, I’m getting 50 ng tests in the mail today or tomorrow, I was just an occasional smoker mostly once a day at night time, is it just the sensitive tests that show a positive result, i’m 5’7″ 200lbs!? thanks…

      1. Hey I had to take a CDL dot random drug test… I used mostly synthetic urine, but it wasn’t enough to get to the line so I used a squeeze of my own dirty urine. Is there any possibility I will come up negative on the drug test l.

  6. I smoked pod (two puffs) for the first time ever on April 12 this year and haven’t smoked again since then. They took a urine sample today. Could i test positive somehow? I am 27, 5,6 tall and 143 pounds.

      1. Curious for myself. I don’t smoke at all and I decided to take 2 puffs of my friends joint 5 days ago. Is there anything I can do to decrease THC in my system in the next few days? I just learned I will be taking a drug urinalysis in the near future. What are the odds that I will test positive?

  7. I work in residential real estate maintenance. Most days i am exposed to strong concentrations of second hand smoke from residents in my buildings. I actually felt a little woozy last week and had a Urine test on Friday. I dont smoke myself but I’m afraid i may fail from the second hand smoke. Is this possible?

  8. Dr. I tested weekly for over a year when I was chronically smoking marijuana (dry flower) 4-5 blunts daily (.7g-1g each). Why is it that my THC levels seemed to never exceed slightly over 200 ng/ml? It wouldn’t matter if I smoked 1 blunt or 10. Sometimes smoking one or two blunts the same day as the test. Smoking all day before. My levels would “cap out” around 200? I have now stopped smoking and am sober. Just curious if you have any feedback.

      1. I smoked for 4 weeks straight, was never a chronic user prior. cutoff was 50ng DOT reg. for test.
        Smoked the day before a test and came up “negative”. I’m baffled. Failed a home test the night before test. Comments? Dr. Fudin Much appreciated.

        this was also listed in my report

        “collector did not complete specimen bottles(s) released to box”.
        “specimen validity testing was performed within federal guidelines “

  9. My 14 year old son just tested at 1022 ng/ml THC. Is this considered to be very high (no pun intended)? The lab told us he needed to get immediate help.

    1. It is pretty high. certainly a therapeutic level that can get you into trouble. And I agree, he needs help!

  10. How will I fair?

    On Sat April 27, 2019, I had a few drinks ( happy drunk) and a couple hits from someone’s blunt/joint. Prior to this for the month of April, I have had a drink edible of 10 mg THC every Wednesday. I work out 4-6 times every week and I sweat it + sit in the sauna for 20 minutes minimum every time I hit the gym. I worked out between April 27 and May 1 and consumed high calorific foods. I am 165 lbs, 5’9 & with a slight belly fat/ core muscle. My UA was fairly concentrated with coconut water, B vitamins, steak soup + I have remained well hydrated and flushed out a lot in the interim days. I consumed a high protein high fiber diet combined with multi-vitamins, fat burners (occasionally but not on the day of my UA). I got UA tested @ 50 ng/l on May 1 that includes ETG testing for a court order. What will be my possible result?

      1. Hi

        I was wondering I haven’t smoked in months, I toll 3 hits in January of this year, about 4 hits at the beginning of April and 1hit on 4/20. I had my drug test today and I had only about 4 ounces of water to drink before the test. Will I test positive?

    1. This country, and the world, really needs to get its priorities straight. I’m still trying to wrap my head around why smoking a plant is illegal, and why people are incarcerated because of it.

      Am I the only one that finds all of this to be the biggest waste of time. Ohhhhh… ahhhhhh you smoked a plant, you’re going to jail, you’re getting fired.

      Preached by the same people sucking down bottles of Wine, Scotch, and Prozac

      What a crock of horseshit.

      1. you got that right brother hate to be dealing with this crap. and its funny how the least harmful drug stays in system the longest. keep on toking. one.

  11. How long do you think it would be detected for a 15ng/ml cut off level. I smoked 3 times in a 33 day span. Before that i hadnt smoked. For 7 months. Im also skinny, been working out. Staying hydrated, eating great & detoxing

  12. I smoked THC vape “dabs” high concentration THC about 40 days ago was the last time. I am 6’4″ skinny and fast metabolism 180lbs or less. Took a drug test today with a 20ng/ml cut off for THC. Drank water all day and took vitamins for urine color regularly urinated every half hour or so before test. I think I am in the clear?? What do you think?

  13. I am a female, 5’10, 160 lbs.

    My blood screening had the following results:(Copied exactly)
    0.060% alcohol
    2.3 ng/ml Tetrahydrocannabinol (THC)
    11.7 ng/ml Carboxy THC
    This was indicated as a “high level of THC” even though I did not feel impaired and was able to conduct work using a high degree of concentration and fine motor skills. Any perspective?

    Thank you in advance.

  14. Hello Dr. Fumin

    I am a 6’1 235 lb 21 year old male who used to smoke mid to upper grade marijuana every day for about a year up until mid February of this year. I have a little less than 2 weeks until my urine test. I have calculated 84 days in total from the day I stopped to the day of the test. I just recently tested myself and came out positive with over 100 ng in my system. I have about 12 days left until my test, do you think I can pass?

  15. Hey Doc! I wanted to discuss edibles! Would one, 10 mg THC serving (fruit snack) be considered a “single use”? What would that 10mg serving equate to in ng/ml inside the body? Experimenting by using at home tests in the past I tested positive at 50 ng/ml cutoff (shocker haha) ~12 hours after consuming one 10mg gummy; took another at home test ~90 hours after use and heavy hydration, results were negative. Always a bit weary of at home tests so I wanted to get some science behind it! Not a frequent user in the slightest, 5’8″ 180lbs, in the 17-20% BF range, exercise on average 4 days a week. Thanks!!

  16. I tested 326 ng/nl and I am curious if that’s high? My doctor was alright with it, I live in Oregon and all, but just wondering.

      1. I am about 400lbs I smoke daily but only about 2 or 3 times a day and usually only 5 to 6 hits out of my bong I have a saliva test coming up on the 29 do you think I can pass if I don’t smoke any more till then

  17. Took two puffs of weed for the first time in a year . Not a smoker of weed a year ago either just make bad choices when I’ve had too much to drink. Anyways it’s been three weeks but I took a pre employment urine test today . I should be okay correct ?

  18. Normally smoke 3 fairly strong puffs of flower a night. Stopped 7 days ago, home test (the stricter one, the 15 rather than the 50, gave me one clean test and then a positive on the next day. I’m currently fasting and running most days in ketosis in order to burn fat cells. Will do a carb load day before the test to make sure I’m running on glycogen during piss test and also do a Niacin load day before and day of. Will over hydrate and then supplement with a b vitamin complex to avoid a rejection due to dilation.

    Alll that considered, should I piss clean on a standard issue 50 pre employment screen about 16 days after last toke? thanks for the advice

  19. Amazing read.

    Doc: I am a regular user. Stopped smoking weed between April 1-10 then smoked daily until April 15. Pre employment test with cut off of 50ng/ml in 3 weeks. I plan to eat healthy and exercise daily. I am male. Average build. What are chances I will pass?

    Thank you

  20. I only normally only smoke when my pipeline work is done for the winter for only maybe up to a week. Then i do not smoke until the end of the next job season. But for some dumb reason this year i smoked on march 28 1 hit of strong weed. The next day I got a slight head change off of some not strong pot. Very very slight change.. Then i took 3 mild hits of brick weed it was a pretty significant high but not like that 1 hit from strong weed.almost a week later i smoked 2 hits of not so strong again. That last 2 hits was no later than April 5. On april 10th iland on april 11 I took 2 at home urine tests and passed them. On april 12 I took a preemployment test, I drank about 3/4 of a gallon of water before the test. I urinated 3 times before the test. The test urine was probably the first pee where the water was really really flowing through me. Becauae it was pretty clear (just a little very slight touch if color) and it was a super long pee. I should feel confident that i passed but the amount of responsibility that rests upon me (my family) has me terribly nervous. Im very disappointed in myself even though ive passed with less time and more regular smoking when i was younger. But having children that rely on me has me crazy scared. Even though i should pass i will never again put the my livelyhood at risk. So anyways 1 hit of chronic. Next day a slight head change and nect day 3 hits of regular weed head change then a week later 2 small hits of regular weed. 7days later a urine test at work. This after passing two home tests… Im good right?

  21. Will my boyfriend pass a follicle test if he sits in a garage with me with a fan on and door cracked open while I smoke my medical marijuana regularly everyday? I would like to be free to be able to smoke in the house but they are afraid the second hand smoke will make him fail his drug test for a job he’s trying to get.
    So some places says it’s a myth to fail hair follicle test from second hand marijuana smoke but other sites won’t confirm if he will pass or not from the second hand smoke.
    Will he pass from if he around me while I am smoking?

  22. Does hydration level affect likeliness of a positive test? I did not dilute, and was dehydrated during my test (only consumed 30 oz of water total that morning). If a person is dehydrated (dark urine) how does that affect immunoassay sensitivity?

  23. So I have a test coming up in the next week or so. I abstained from smoking from mid December to the end of February. In March I had 2 fairly high dose edibles and 1 normal joint as well as a joint wrapped in wax covered in kief. I smoked that last one over the course of a week. The next day I get a call for an interview I was not expecting and have since been “hired” and will be getting my test done soon. The total time between my last ingestion of THC to when my test is will range anywhere from 18-21 days. Based on the frequency up to that point would it seem likely that I would pass a 20ng/ml test? I don’t know for sure if that’s what the test will be at, but it feels like a good guess.

  24. I do not use marijuana very often. I took one hit February 26th, then on March 24th I ate a 10mg candy. I just happened to get called in for a random drug test at work the very next day. Apparently the initial test with a 50ng/ml cutoff showed up positive for marijuana metabolites and amphetamines because I take adderall. The confirmation test showed that my level of amphetamine was 8029 ng/ml, to be expected. My thc metabolite level was 15ng/ml according to the confirmation test, right at the cutoff. I was then fired for the positive test. How is it that I showed positive on the immunoassay test with a 50ng/ml cutoff when my level of metabolites was so much lower? The doctor told me its because the tests work differently, but it doesnt make sense to me because they are measuring the same thing in the same units and the confirmation test is supposed to be more accurate.

      1. I have a pre employment drug test coming up. Now, I have a few questions. I had been using a dab pen (pure thc extract) several times a day for about a month or two. I am 5’8 and weigh 170 pounds, with about 10-12% body fat at most. I haven’t taken a single puff of of it since February 26th, and it is April 9th. My drug test is in about 2-3 weeks, I have kept a steady workout regimen and have drank a gallon of water a day every day (not to mention two strong detox drinks and a lot of cranberry juice) since even before I stopped. Am I likely to pass?
        One more question, I also use a juul (nicotine vaporizer) that my friend who is a heavy chronic smoker also used a few times. Would I test positive just for making contact with his saliva, even if he wiped it off? Thank you, I appreciate the answers as I am worried about my test.

      2. If I pass a 50nl home test will I pass a15ng home test I am not by any means a frequent user and haven’t used in 12 days and all I did 12 days ago was take 2 hits of a oil pen

  25. Hello, I’m just curious, I have not ingested or smoked or taken any type of drug for over 4 months. I was thinking about smoking a few hits of weed tonight, I would have 14 days before I might get tested at an interview. I weigh 150lbs, male, 5’8”, 10% body fat at most. Would I test positive for “thc-cooh” after the 13 days and be clean on the 14th? Asking before I make a rash decision. I appreciate your time and thank you for your help.

        1. It depends on how much you ingest and also how accurate that claim is, since quality control generally is not great with these products. The short answer is that you probably wouldn’t test positive, but there is a remote chance you can.

  26. Curious for thoughts behind my usage versus activity levels:

    Heavy user for one year of primarily lower concentration <30% with mixed breaks every month for a week; however, I am really interested in its comparison to my fitness/ activity levels.

    Consistent movement/ activity ranging from mountaineering/skiing/alpine climbing/trail-running/etc. for 6+ years now with no compelling/ noticeable hindrance by my smoking habits. As far as gauging fitness, I have ascended 9000' in around 7miles (Paradise to Mt. Rainier Summit) in 12 hours carrying ~ 20lbs.; capable of ascending 4000' over 4 miles in 80minutes w/ <10lbs.

    Unsure if these measurements help at all but it is how I gauge fitness levels – cheers

  27. When judging by single use or moderate use, im sure it’s based on amount smoked compared to a single day, but if I smoked 4 hits total out of a vape pen the entire night, does that fall under moderate use or single use?

    It’s a concentrate so I’m thinking moderate, but does it jump even higher to a heavier level of smoking?

    I just scrolled through an impressive amount of questions asked. Thank you guys for taking the time to explain things to us!

  28. I use CBD drops every day Morning and Night. I use Lazarus Naturals and they state it may have .03 % of THC. I am curious if i will test positive on a drug test that does have a limit if 50 ng/ml.
    I know people that want to use it also, but they know they get random drug test and and are un-sure if they should use it.
    Also if it it used as a Balm or Massage oil, does it enter the blood the same as the drops would?

    Thank you,

      1. Doc if I smoke a roach witch is like 3 to 4 puffs will I test dirty in my next drug test ? Or how long will it take to clear my system I used to smoke very heavily but I been clean for almost 4 weeks an I need a head change any chance of me passing my drug test ?

      1. Took 2 hits Saturday night. Never smoked before that. Have a drug test tomorrow. I’m 5’10 230lbs. Home test was negative. What are the chances of me passing this drug test?

      2. Good evening Doctor,
        if I ingested two edible gummies of 4.5 mg each on March 29th and another single edible gummy of 4.5 mg on March 30th, (a total of 13.5 mg), will my urine drug test scheduled on April 11th or April 12th (I have the options for either day) come out negative? I want to clarify that it had been a month that I was waiting for a callback for a certain job, hence I believed I had not been accepted for the job. They randomly called me four days ago to offer me the job and schedule my drug test. I am an active individual and have been eating extremely clean and exercising daily. Do you think I have a good chance if I am drinking a lot of water as detoxing to pass the test? I don’t think I ingested over the 50ng/mL limit on the test.. but I would like to know if you think I will pass the test.

  29. Hey Doc, so I was a chronic user for the past few years, I had to quit for tasc services via probation. My initial test said 112ng in my urine, the next was 107 ng, the next was 100ng. The 3rd test was taken after 13 days. I’m waiting on my next test to come in. Currently 24 days clean. I’m 23, 6”1, 230. Is there any reason why my levels arnt significantly dropping?

    1. If used chronically, cannabinoids can sequester in body tissue and take many weeks to come down. There is a way to determine for new versus old use by testing carboxy THC to creatinine ratio

      1. Hey Doc so I received my my results for my 20th day of being clean. Currently 29 days clean but that test showed a major spike in my levels. It went from 100 to 170. Which makes zero sense because I’m not even around it anymore. I have started working out everyday and drinking only water. Also on phentermine 37.5 to help lose weight. I have read where losing weight can increase these. But my po will just see an increase and assume I’m smoking again. Is there any reason for this increase and if so what can prove I’m not smoking.

      2. Hey Doc, just called back to asked my thc creative levels and they went from 87 to 137. I was told this is a good thing because it clearly shows I’m not using which leans in my favor. But just wanted to verify with you.

  30. Hello, I had a pre acceptance test for a non profit culinary training program today and the dip strip came back positive for thc. When I went back to the organization they accused me of lying when I stated I haven’t smoked since September 2018. They intimated that if I admitted smoking it would be ok.. I don’t feel comfortable lying and going with their assumptions because of my pride at being sober off many drugs. They sent me to different clinic for a ln actual lab test… I am over 300 lbs and have been around some ppl that we’re smoking and was wondering if that’s what affected the dip strip test and what this new test will show? Thank u

    1. Ask them to send the sample of definitive testing by chromatography. There are several drugs that can cause false positive THC, including over-the-counter drugs. No, being around people that smoked marijuana would not cause you to test positive.

  31. I was offered a job last month that required a drug test. I had 13 days to take the test. Up to that point I was smoking the thc oil…usually 2-3 hits on weekdays, and 6 hits on the weekends. I was using the the easy@home drug tests to see if I was clean. My first test failed, the 2nd had a faint line. The next 7 after that I passed with 2 lines. I even tested my morning urine the day after the test and passed. I found out that I was going to have to take the test again because my urine was too diluted due to the fact I had to “fast” for labs 12 hours prior…moving forward I was given an extra 21 days (34 in all) I kept testing myself and passing. I went to the gym at least 8 times and did the stair master for 30 minutes, elliptical for 15 minutes and the bike for 15 minutes as well. I drink a lot of water so that wasn’t an issue for me either. Do you think I passed?

  32. I’ve been using a CBD oil for about 7 months. Just took a random and failed. How is that possible with such a minimum amount of THC in this oil.. Actually didn’t take any 24 hours prior to test. Also don’t understand the levels..Company said that my level numbers were 2..2.

  33. Can anyone please advise me….

    If a urine test returns 4.4ug/L for THC, is that a trace or high level of THC?

    If high, would it be enough to cause someone to hallucinate?

      1. Dr. Fudin. I took 4-5 hits of a joint 6 days ago and took a drug test today. I am 250 pounds and 5 ft 10. Will I pass my drug test? Before that I hadn’t smoked in 4 months. They are sending the drug test to the lab

  34. Hello! So i’m so confused with the article because I don’t get the grams & etc . But anyways, I hit a dab pen for my first time in Jan 22nd 2019 or 24th . I hit it like 2 times I think and honestly I didn’t know what was in the dab pen until they told me it was THC. I got a job yesterday (March 22nd) and I took a drug test. Will it be positive? Just recently I had food poisoning so my stomach is really clean and I been using the restroom and most of the time I was dehydrated . Will I still pass even though it was my first time?

    1. I briefly inhaled some second-hand pot smoke. I immediately left the room. 35 hours later took a DOT drug test at an airline. I should pass since I’m a non-user correct?

  35. I took a urine test this morning. I have smoked 2 times in three weeks. One hit each time. I last smoked Sunday night. The time before that was probably 2 weeks. Today is Thursday and I took a random, I drank enough water that my urine was clear with just a slight tint of yellow. I’m 5’9 195. I’m average size. Do you think my chance are good? Thank you

    1. I smoked At most for times a week for a good amount, have been clean for three weeks do you think I will pass a quest diagnostic test for a job internship. It’s a piss test

  36. Hi Dr. Fudin,

    I hope you are doing well! I have a pre-employment drug screen coming up in 2 days. I used to smoke once a week at least only, max twice on/off weeks. I stopped completely on January 15th and have used none ever since. It’s been 60+ days, I weigh 115 pounds and am 5”2. Some tests at home have been giving me negative results but at times positive. What is the likelihood I will be passing my drug screen?

    Thank you!

      1. Hi! I have never been a smoker before but the last two months I have taken one or 2 hits 3-5 times a week. I just quit 3 days ago and I have a job coming up that will drug test me. I’m trying to push it off for two weeks. I am 5’7 120lbs and 18/20% body fat. How long before I can get a negative result?

      2. Hi I’ve been clean for a month now. I took maybe 4 hits on the 15th of March. About how long will it take to pass a 20ng weed test?

      3. I don’t think that’s completely true, I think it affects people differently,,,to be honest I perform better when I use to smoke and I paid attention more also

    1. Hi I’ve been clean for a month now. I took maybe 4 hits on the 15th of March. About how long will it take to pass a 20ng weed test?

  37. I used to be a frequent user. I smoked 1 hit off of a dab pen on Sunday afternoon (3/17). How long before this will be out of my system. I am 24 years old and 200 lbs. Not very active. I may be randomly tested for work at any time and do not want to lose my job.

  38. The marijuana used in the study from 2001 contained only 3.58% THC. Nobody smokes marijuana with that little THC content. Many of the strains that medical and recreational users have access to in the real world have 20% Or even 25% THC.

    If you were to recalculate the total intake of THC in a joint (based on the 753mg marijuana per joint in the study) with a strain containing 20% THC, the joint would have approx 150mg of THC.

    Returning to your patient – 2 hits from a joint could easily be 1/3 of the entire joint. This means that she realistically smoked about 50mg of THC – twice what is indicated in the study and it is highly likely that this would cause a positive test result.

  39. My thc levels were 900 when I first got tested. They want to see my levels go down and u have not smoked in a week. Will that lower my levels? And if so can I smoke today and still not raise the levels above 900?

  40. hello,great site,59, 220 lbs,.fit active male,two toaks three times a night at 3, 6 and 8 pm daily,for 35 yrs never smoke during day back yard homegrown.i hurt myself at work at 7:30 in morning.went for urine test and tested positive at 181 ng/mll this put me over the 15 ng/mll. I feel that i was not impaired . my question is.Was the urine test the proper accurate test for impairment.. I do not feel impaired in the mornings. i work as a heavy duty mechanic and welder,. Do you feel that i would be impaired to do my duties. i have a great record for not getting hurt or making mistakes at my job. I would appreciate your view on this situation. I have quit smoking for the last week and don t need to smoke but i enjoyed it over they need me to go see a substance abuse proffesional and rehab program, which i feel unessesary .but to have my job back they have hoops to jump long to clear my system. Thanks for your site and opinion Tom from canada awaitinng a reply

  41. hello,great site,59, 220 lbs,.fit active male,two toaks three times a night at 3, 6 and 8 pm daily,for 35 yrs never smoke during day back yard homegrown.i hurt myself at work at 7:30 in morning.went for urine test and tested positive at 181 ng/mll this put me over the 15 ng/mll. I feel that i was not impaired . my question is.Was the urine test the proper accurate test for impairment.. I do not feel impaired in the mornings. i work as a heavy duty mechanic and welder,. Do you feel that i would be impaired to do my duties. i have a great record for not getting hurt or making mistakes at my job. I would appreciate your view on this situation. I have quit smoking for the last week and don t need to smoke but i enjoyed it over they need me to go see a substance abuse profesional and rehab program, which i feel unnessesary.but to have my job back they have hoops to jump long to clear my system. Thanks for your site and opinion Tom from canada

  42. Hello Dr. Jeffrey Fudin,

    I am a daily smoker and slightly overweight. I will be taking a urine test 10-14 days from when I stopped smoking. I assume that is cutting it too close for comfort. If I were to moderately dilute my urine by consuming water, is it likely to beat the test without raising red flags?

    Secondary question, what measurements are used to determine if a test is invalid based on dilution?

  43. Hey,
    I took one hit on weed joint on Saturday morning at about 9:30am and had a urine test on 11:30am on the Monday morning after consuming a lot of water the preceding day. I urinated first thing in the morning and consumed water up to the urine test. I am 6ft 5 and weigh 209lbs. I rarely ever smoke.

    Your thoughts please.

    Many Thanks.

  44. Hello Dr,

    I smoked on Friday 3/8, a puff or two on 3/10 and ate a gummy bear and 1/3 of a joint on 3/12. I’m a 30yo male at 191lbs and 22% BF – is it likely to test positive or negative? It’s a pre-employment test.
    Thank you

      1. How did your test go? I have a test on 4/12. I smoke 3-4 hits before bed at night, everynight. Just wondering what my odds are. Hope your test went well.

  45. Hi
    I’ve been smoking for 12 years and quit December 29th 2018 it is now 3/13/19 and im testing positive for 10ng/ml with one week spiking to 16 ng/ml how is it possible to spike with no new use and can I prove no new use with a hair follicle? How can i show that I havent been using? These uas are being sent to a lab with no cut off only showing counts. They also show my creatinine levels. It’s like the people reading the print outs dont understand that that low of count compaired to my creatinine levels mean that in NOT using. What can I do to prove it?

  46. I commented a little while ago about stopping on 1/18/19 & testing positive 2/22/19 but I forgot to add that I’m 5’7 & 135 lbs if that helps to specify your answer to my inquiry, Thank you!!

  47. I was a chronic user up until 1/18/19, I am now being tested regularly. On 2/22/19 I tested positive & the lab result came back at what the lab personnel said was a “9” today on 3/12/19 I tested positive again. The lab rep said with a level 9 almost 3 weeks ago I should not be testing positive anymore. I have not smoked since 1/18/19. Is there any explaination as to why I could still be testing positive? Could it just be because I was a chronic user? Can you explain what the levels mean, a 9 for instance. Please & Thank you!

  48. I feel like I should be ok but I have always read that THC is fat soluble so I’m not sure if my weight will affect my chances.

  49. Hi I am 25, 270 pounds and I smoked out of an oil pen for 3 days with my sister on February 17th. I have a drug test in the next 2 days, prior to smoking with my sister the last time I smoked was July of 2018. I was a daily smoker for most my life but because of my job I quit entirely, smoking only that time since. What do you think my odds are of passing? Im in a legal state but applying for a Federal job so state law doesn’t matter to my employer.

  50. Hello Dr. Jeffrey Fudin, I’m Justus Wilmoth. I smoked 3 or 4 hits of marijuana on the 6th and 7th and tooks 4 more hits on the 9th and have a urine test on the 14th. I try to drink alot of water and I play basketball so im very active. In 14 years old and I weigh 127 lbs and am 5’2. Will I pass?

    1. Justus, With that usage at your age, I’m afraid there’s a lot of things you will not pass moving forward. If you’re able to, I suggest you stop smoking altogether or get professional help to stop smoking.

        1. It can be addictive. Pretty much anything that causes pleasure can, food, sex, gambling. I love weed but let’s be logical and realistic and change the opinions we have when new information is presented.

  51. Hi Dr. Ludin,

    I have been a regular, daily Marijuana user for the past couple of years. I stopped consuming on 1/22/19 and it is 3/12/19 today. I am 100 lbs, 5’1.5, and have been drinking plenty of water since I stopped. I have also been eating better and go to the sauna mostly every day. I have taken a couple of at home-drug tests and have tested negative lately, except for a different at home test, which I tested positive on this morning. I will take the pre-employment drug test on either 3/14 or 3/16. In your opinion, will I pass a urine test?


  52. Hi Dr. Fudin,

    I have been a regular, daily user of Marijuana for the past couple of years. I stopped consuming on 1/22/19 and it is 3/12/19 today. I will be taking a pre-employment drug test in 2-4 days. I weight about 100 lbs and am 5’1.5. I have been drinking plenty of water since I have stopped. I have taken at home-drug tests and tested negative for some, but a different at home test came out positive this morning. What are the chances of testing negative on the real test?


      1. Dr. Jeff,

        I started smoking thc oil and had 9 days without from December 30th until January 9th. From the 9th of January I smoked just about everyday until I found out about a job that had a pre-employment drug test around February 12th. My date was set for 13 days later…the first home test FAILED, two days later I saw a faint clear 2nd line. The next 7 home tests I passed. I actually drank too much water the day of the test and was told (damn near 3 weeks later) I had to take it again LOL. So now we have 33 days later…will I be good?

        How was I smoking?
        Almost everyday up until Feb 12, 3 puffs max on weekdays, 6 puffs max on weekends

        At least 7 days I did:
        30 Minutes Stair master
        15 minutes elliptical
        15 minutes bike
        I walk about 1.5 miles when I go and come from the gym

        Water: I AM A BEAST when it comes to water.

        Last thing, I have even been testing my morning Urine and I am passing home tests….WILL I PASS!!!

          1. Oh…I did not think this question posted…I actually typed it again. BUT YOU DON’T HAVE TO TELL ME TWICE…..I’m giving my THC pen away and I’m DONE!!!

          2. *************UPDATE
            So the 2nd drug test was lost. I had to retake my 3rd today at 50 days clean….How Do You Like Them Odds????

  53. Hi, I smoked a little bit on the 6th and 7th and smoked 4 puffs on the 9th and I have a test on the 14th I’m trying to drink alot. I play alot of basketball so I’m active I’m 127 lbs 5’2 and 14 yo. Will I pass?

  54. Hello Doc,

    Question I recently went to a dab bar here in Wa State and tried a 4 different small dabs of 85% thc wax. I haven’t used any Thc before this for 2 months or longer. I know I will have a drug test in about 6 weeks for my doctor so I am going to stop. The test detection is 20 ng/ml and carboxyl thc at 2ng/ml … I’m 160lbs low BMI and just a one time user. Curious what you think my test results will be if I give it about 6 weeks to clear out. Thanks again!

  55. Hi Dr.,
    I have smoked 3 times in my life. Once about 5 months ago, the second time about 4 weeks ago, and most recently last night. I took two hits off of a pax vaporizer. I just found out I have to take a drug test within the next two weeks. I’m going to try to put it off for as long as I can, but how long do you think it will be before I should be able to pass, it is an employment test so it should be 50ng? I run every day and drink a lot of water. Yesterday I ran 16 miles before smoking. I typically run about 4 miles a day. Should I try to exercise as much as I can? I ordered some home drug tests off amazon and they will be here in two days, so I will try to start tracking it. Any advice helps. Thanks!

  56. Hello, Dr. Thank you so much for this service!

    I took 3 hits of marijuana Thursday at 10pm and I have a UA for probation tomorrow, Tuesday, around 5p. I’m relatively active and eat healthy, 6’0, 185, 37yo. Think I’ll pass, or fail? Thank you!

      1. Hey doc, way to crush a 14-year-old’s spirit somewhere in another comment. Your omments are often a bit demeaning, out of touch with research on the health benefits of cannabinoids from around the world, and indicative of a lack of knowledge about the very long history of the medicinal use of marijuana. I wonder, how much does Purdue (or whomever) pay you to go to their pain treatment conferences and prescribe their legal versions of heroin?

        1. Purdue doesn’t pay me a dime. Oxycodone is not legal heroin, in fact oxycodone is closer in chemical structure to over the counter dextromethorphan – by your comparison then, Robitussin is legal heroin – don’t fall for the PROPAganda you hear. Irrespective of what you believe, there is por evidence for THC as an analgesic with the exception of certain specific neuropathies. If you believe otherwise, respond with some placebo controlled studies that have been peer reviewed and published in a professional journal – then you’ll have my attention. And for the record, there is clear evidence that chronic use THC in young teens affects brain development.

          1. Dr Fudin your reply to the 14 yo was spot on, this is coming from a mother of 4 children.
            Marijuana is an Addictive drug!!! Reading these questions to you, it is obvious Marijuana is an addictive drug. When you are plotting on a calendar when you have to do a urinalysis and when your able to do your last hit in order not to test positive, your addicted.
            Marijuana used to not be addictive back when i was in Highschool in the 80s but its a whole new plant its no joke!!

  57. Last night, I took about 5 hits of weed. Prior to that, the last time I smoked was about a year ago, so I’ve smoked twice my whole life. I have a drug test in about 20 days. Do you think I will pass? I’m 116 lbs if that helps.

  58. Just tested positive at 200ng. I am 6;2″ 165 lbs. I smoke 90% THC daily, if I stop today, how long before I test clean?

      1. Hi, I took like 3-4 big hits of medical marijuana on Saturday at 4 pm and have a test this Thursday will I test clean? I’m 14 yo and 127 lbs. Thanks!

  59. Hello, really loved the article so much great information. I have to take a drug test tomorrow. I’m female 5’3 probably 20% body fat. I took 1 hit 3 days ago. Other than that I smoke once a week or once every other week. What are the chances I’ll pass my drug test?

  60. I last smoked 1 gram over the course of 4 days starting on February 15th, prior to that I hadn’t smoked in two months. I was a heavy user for almost a year. I have a pre employment drug screening on March 11th. I took a home drug test and it was negative. I’m about 113 pounds, I don’t work out often but I’ve been trying to work out and drink plenty of water. What’s the likelihood I will pass my drug screening?

  61. Hello doctor, so I was a somewhat frequent smoker for 4 weeks, train twice a day my entire liife intensively, have a crazy metabolism, low body fat percentage. I stopped for around a week In a half . Then took a hit or two then stopped for 6 days then took a test in which the cutoff test was 150ng/ml. Keep in mind I was sweating and drinking lots of fluid the days leading up (and exercising twice a day with intense cardio) and the period where I was a frequent user for 4 weeks it was maybe a few hits a night or a small joint maximum.

  62. Hey Dr
    I haven’t smoke since 1/21/19 and it 3/2/21 I’m a heavy smoker the pass year about 2-4 grams a day. im worried about passing the cut off level for uriuary test. 15ng/ml

    1. I relatively close to same boat as above. My details: 5’7″ 142 lbs male 28 y/o Didn’t smoke till Jan 4, 2019 and was clean for around 45 days prior. I smoked around 1 g of mids or so a night till Feb 12, 2019. I have abstained from smoking since. I will be running for the next 2 or so weeks to assist in boosting my metabolism. I was hoping i can be be clean 3/19. Do you believe that is possible?
      I am unsure which to rate myself.
      Daily use 10-15 days
      Chronic heavy use >30 days

  63. I accidentally took 2-3 puffs off a friends vape on 2/22/19. Thought it was just nicotine but then learned it was weed oil, that’s all I was told. I have since been overcome with anxiety since I am waiting to hear back about a job. I do not smoke at all. I did try it a few times but it was like 6-7 years ago and didn’t like how it made me feel. Anyway. Over the last two days I have done multiple at home tests which have been negative and even went to a lab today 2/28/19 and peed in a drug test cup and it also came out negative. Lady at the lab said she didn’t think I had anything to worry about but everything I’ve read about this drug is it stays in the system(fat) a long time.

    Are all all drug test cut offs 50 ngml for thc or can they be 20? Because that is what I’m worried about honestly. The job is part of the Federal Aviation Administration

    1. Employment tests are generally 50ng/mL. You probably have nothing to worry about with minimal one time use a week ago.

      1. I just took a UA Pre Employment drug screen today, 1/1/2019 . I used to eat about half a brownie, nightly for sleep on and off for about 2 months. My last time consuming a brownie was roughly 35 days ago. I purchased an at home THC testing kit which indicated both times I tested myself which was 2/27 & 2/28 that it was negative with a faint red line. I’m female, age 43 in decent to good health. 5’0 ft and about 119 lbs. Im not exactly sure what my BMI is but I am not super lean nor am I overweight, maybe by 5-7 lbs and I do not work out but do eat mostly healthy with plenty of vegetables and low carbs. I drink a cup to a cup and half of coffee every day and a cup of either green tea, peppermint or other types of herble tea usually 3-5 times a week.About a liter of water a day sometimes with lemons and genarally remember to take my multi vit daily.
        I’m curious to know if my at home negative results with be that of the same from the lab results. I only recently started consuming the half brownie in October 2018 on and off ( some nights I had nothing a few nights in a row, also some weeks) I would say I ate a half a brownie on a regular for about a month to month and a half before stopping completely 35 days ago from today.

      2. Hello doctor ,
        I was a heavy smoker for 3 years (4-5 times a week ). I stopped 13 days ago and when i tried the home kit i tested positive . I m 5 11 , 210 pounds . How long it will take me to test negative . I have a pre-employment drug screening coming in 2-3 weeks . Thank you

          1. hey j.w about blood test … how long would it take to get down bellow 2.5 ng/ml of blood , been a chronic smoker for years j.w i here 12 hrs some times 2 days . if i pass a home.swab that macs out at 20 ng/ml of saliva should i be fine

  64. I smoked multiple times daily for 3 months. I would say it averaged out to around a quarter of an ounce a week. I abstained for 3 weeks, smoked a half over the course of 2 weeks, and have since been clean for 30 days. I know your not some type of magical guru who can predict the future but based on this information what would you say my chances are of passing a 50ml drug test? I play college baseball, I am 5’9 170 pounds with a stockier build (although i have lost 20 pounds over the last 3 months.) Thank you!

  65. I’m a very chronic smoker for 3+ years .. I’m 6’3 170pound male.. I’m active I play college basketball. If I stop smoking today and take niacin and do a lot of sweating do you think I would be clean by the 17th of March?

  66. Is this only for inhaled products or does the results also include tinctures & topicals? I’m on pain management and since the ‘opioid crisis’ my pill intake was basically cut in half. As a result my PM said i could try alternative medicine. I found a wonderful tincture called high cbd tincture made by green halo. It’s a full spectrum product made with a cannabis plant that rates at around 7%thc 7%cbd. I’ve been taking .5ml twice a day and it’s helped me tremendously in addition to my pain pills. I also found some topical products by the same company with the same 7%thc/7%cbd to help instant pain relief. But now my PM is saying i need to be under a 50 rather then the 100 I’m at. First off i have no idea what that means but after reading a few articles I’m assuming it’s 50ng/ml which sounds like you basically can’t have any thc in your system. Is that correct? Or is there a way i can continue taking this tincture while coming under that 50ng/ml? And if i have to stop taking the tincture could i still use the topicals with the thc/cbd and be safely under the 50ng/ml? And on that note what is the highest thc level of tinctures & topical could i use?

    Thanks for taking the time to read this convoluted message lol.

      1. So I smoked on February 9th, took two puffs of a blunt. Now I got a random UA today on the 25th. I’m 165lbs and 6’1… I drink a lot of tea and fluids, and have taken cranberry(azo) gummies on and off last week. What do you think my odds are of passing? It’s a government UA with a 50ng/ml cutoff. I’m pretty active and am required to go on runs (3-4 miles) and on the 22nd I did a 12 mile march.

  67. Dr. I tested a negative on a 50ng/ml test. After I took that test I smoked hashish at night for the past 2 days. (Maybe .15g in all) how many days after cessation do you think it will take for me to be able to pass a 15ng/ml ua?

  68. I am a light user (4-5 times a week) and haven’t smoked in 10 days and I have an upcoming work pee test next week. I did a home test yesterday and it came up negative. I went one step further the same day and went to a “Doc in the Box” and paid $50 for a 5-panel test, which came back negative. When I take my employment test next week, I am concerned there may be a lingering platelet or two that releases that day and causes a positive result. So the question is… based on my negative home test, and the negative “Doc in the Box” test, am I THC free/undetectable?

      1. Thanks Doc. It’s not for a security clearance, I’m assuming (and I’m no Doc) – that’s it’s going to be the same DOT 5-panel that I paid $50 for at the clinic. In your opinion, what type urinalysis do most US employers use? Immunoassay or chromatography? My thanks again….

  69. Hi, I am 18 years old and I weigh 48 kgs. Last time I smoked was on the 18th of January and I smoked like 2 cones, I have not smoked since then. I have to do a urine drug test for a job some time this week or next week, will the tests come back positive or negative?

    1. That’s literally me right now. I never smoked until Sunday and I have a drug test Friday. I workout everyday and drink a lot of water so I am wondering how long it will stay in my system. I weigh 130lbs

  70. The past month I have smoked about 5 times, each time about 3 hits. Last time I smoked was 5 days ago. I am an in shape 5’5 145lb male. I took a First Check THC test that tests for 50 ng/ml and tested negative. I have a drug test in 3 days. Is there a chance I can test positive or negative?

  71. I need an answer quick I smoked Saturday and Sunday last week but no a whole joint a couple of hits here and there both days haven’t smoked since and have a drug test next week will I past or fail

  72. I passed a pee test about 3 weeks ago, haven’t smoked any weed since, until last night(2-3puffs) would I be able to pee clean below 50 ng/mg in a couple days… is that even enough to register? tIA

  73. Hi ive been a chronic smoke for years now and smoke 4 joints a day. I stopped for 3 months in 2015 and started back smoking 4 joints a day. Im 5″10 250 pounds How long will it take for me to become clean. Just stopped today. Doing a career change.

      1. Hey Jeffrey, I’m super nervous. So I don’t smoke weed at all until Friday night about 8-9 pm i was super drunk and took a puff not a deep puff just a quick puff of a friends blunt. I pee’d all night from the alcohol. Woke up about 8 am to find out that I had a UA at 5 pm that day. And I couldn’t prepare for it. However I did drink 2 bottles of water when i woke up and pee’d twice beforehand leaving my house.. Is there any chance that I could’ve passed that UA? I weigh 105 pounds and I’m 5’2..

  74. Hi Jeffrey Fudin,

    This is a long shot but i’ll have a go. I haven’t inhaled for months but 11 days ago I took 1 puff of marijuana. Today I had a drug test for work and I am very worried that it will come up positive. I have low BF percentage and active. I tried 2 of those dollar store tests and they came out negative (apparently they test for 50ng/ml).

    Am I screwed?

  75. Hello,
    I live in New Jersey. I have been a regular daily user of marijuana for several years. Within that time period, I have stopped for weeks at a time, but then returned. About 3 months ago, I moved from pipe to vape and have been taking about 10 to 20 vape hits per day at 380 degrees. I was recently offered a teacher job, and I was surprised that they required a drug test. I stopped vaping/smoking at that time which was on 1/11/19. I took a FirstCheck test on 1/25/19, so was clean from 1/11/19-1/25/19 and I tested positive with 32 ng/ml. I am concerned about how long it will take to test negative. Today is 1/30/19 and I am going to self test again on 2/1/19, and plan to self-test every Friday until negative. Here is my question, does that result of 32 ng/ml show how much thc is in my bloodstream? And, if it is low enough, under a certain threshhold at the time of my actual test, do you think they will say that ok it is low enough so let’s give him the job, or it has to be completely negative for them to say its ok? Any experience with being approved for teacher jobs? By the way, I am 6’4″. 205 lbs in great shape and thin and work out daily. I am tempted just to go in there and tell them, “hey, I smoke occasionally, and it helps me with relaxation, but I would never do it on the job.” Because they do seem very cool, but I don’t want to “blow it”! Thank you for your advice. Jackson Browne

    1. Jackson, Here are the answers to your questions…

      Does that result of 32 ng/ml show how much thc is in my bloodstream? No

      And, if it is low enough, under a certain threshold at the time of my actual test, do you think they will say that ok it is low enough so let’s give him the job. No, they will not know the difference and they won’t care; to them, positive is positive

      Any experience with being approved for teacher jobs? Yes. Generally any positive is a problem. They do not want the liability if a parent sues for ANY reason, or there is some sort of mishap that can be blamed on “drug use”. Also, they will look at this a a poor influence on students who are being taught not to use drugs from a healthy lifestyle perspective.

  76. I smoke 1-2 hits a day for 2 weeks from a pipe, I am 5’10” and 215 lbs., and before this I didn’t smoke for 8 months none at all. I walk around a lot for work average about 2.5 miles, it was 17 days since I last smoked and 2 days after my urinalysis I had did an at home drug test passed the 50ng/ml 2 times, and there was a line starting on the 15ng/ml line utilizing the uTest at hom test. I am worried I may have failed the urinalysis at the 15 ng/ml gc/ms cutoff level, but passed the 50 ng/ml initial cutoff immunoassay test. I have heard of people failing at 38 ng/ml before which is below 50 ng/ml and got fired. I’m really worried. I failed please give me an insight as I am very paranoid.

  77. I have smoked marijuana every single day for 25 years. At least 4 grams a day. I have a looong list of health issues and refuse to take the narcotic cocktails most Drs like to prescribe as they leave me in a border line catatonic state when taken together and when taken individually do not work. I smoke like this daily. I still work as a mgr in one of the top100 companies in the world. I raised 3 kids. I have a healthy marriage and I drive regularly. When I do not smoke I can barely function due to the massive amounts of pain, muscle spasms, Charlie horses, numbness, burning etc that i get wide spread that’s darn near debilitating. Smoking marijuana is not bad. It doesn’t make you stupid like it shows in movies or on that 70s show lol. It makes it where people with severe agonizing pain can function on a level that doesnt leave them at the mercy of care givers. It could be really great to see more education on the benefits of THC. CBD oil doesnt work for me, edibles do not work for me just smoking it. Why do you think that is?

    1. Mona, There are a number of reasons for this. Smoking gives a quicker peak and that may be important for your response. Also, the percentage of THC and strain will be important. The data for pain alone is poor, which the exception of neuropathies and certain types of GI pain related to gastric seizures. But, even real chronic pain comes with anxiety and other issues that could respond to cannabinoids. Generally pain make anxiety worse and anxiety makes pain worse, so that interplay could also help to explain why you in particular are responding.

          1. Thanks for your reply. Just so I’m clear , a person that never smoked marijuana, took a single puff, and that single puff would be detected in a hair test up to 4 months later?

          2. Thank you again for the reply. I will update after my test on Feb 4th. I haven’t smoked for many years. Unfortunately I took 1 puff just after Thanksgiving and didn’t know I’d be subjected to hair test. But I do have a test on feb 4th. Hopefully I’ll pass and wont make the mistake again

  78. So, on Saturday(yesterday) I took about 2 puffs maximum of weed for the very first time in my life(was not proud of myself). One puff from a bong and one puff from a vaporizer. I also found out that I have a drug test that I will have to take by Thursday. Am I going to pass? By your explanation I should be well under 50 nans, so I should be fine, right? Weed is something I will never do again.

    1. unlucky looks like you chose to smoke it, you should be worried your gonna fail it. im only saying this cause you are disrespecting weed, you underestimate it

    2. In the exact same position as you. My medical test is this Thursday too and I smoked last Thursday. Let me know if it went good for you? Good luck

  79. I think the numbers are too low. I know most chronic smokers, even very thin ones would have trouble passing after 30days… I am below average weight and extremely active and it took me 2,5 months to pass
    I would say 45- 60 days at least in most cases for cronic users

  80. Dr Fundin. So if I hadn’t smoked in several years and smoked 2 hits off vaporizer pen at low power what are the odds I would test positive at a 50 mg/no cutoff after 24 days? I’m 6’1 and 190lbs and fairly active a normal body fat percentage. Thank you

  81. In need of help…..
    My wife and I are in a family legal battle where marijuana use is becoming a factor, we live in illinois, she was approved for her medical card, however she was told to do some research on “legal levels of intoxication” per state, and mostly I have found that 5 mcg seems to be the standard, for operating a vehicle, she doesnt drive, I’m having a difficult time finding what I need, any help would be greatly appreciated.

  82. I’ve smoked about 5 times a week for 7 years. In the last 3 months, I’ve smoked a few puffs from a shared joint or small hit from a pipe 3-4 times per month. I have 24 days before a drug test. Do I have a realistic chance of passing if I do not smoke at all during this 24 day time period?

    1. No, you were a chronic user and the need yes you slowed slowed down. However, your body has been full of thc for 7 years. If you had quit cold turkey it could have taken you anywhere from 30 days to 90-ish days to be clean. Depending on your metabolism and body fat and so on. I have heard many stories and witnessed chronic users being clean in as little as two weeks, or as long as 3 months. Everyone is different, run and pound water, good luck buddy.

  83. My friend had not smoked in nearly 6 months, he took 1 or two puffs off of a joint and worked out several days after. He’s a big guy but in very good shape. 13 days from the time he took those puffs he had a screening at 15 ng/ml. Is it possible he passed?

  84. I’ve been smoking a lot for the past month prior to that no. I have a drug test in a few days. I’m looking to detox water eyc. Do I have a chance

  85. I am in the process of writing an advisory/advocacy letter to my states department of corrections to help them rewrite their policy concerning positive UA results for thc that are a result of consuming hemp based cbd products that contain >.3% thc. Currently our state has medical cannabis laws but those on supervision are not allowed to participate because of the schedule 1 classification of thc. A standard condition of supervision being that a parollee must remain compliant to both state and federal laws.
    With the passage of the 2019 farm bill, one section made changes to the controlled substance act
    completely removing hemp based thc from being a scheduled substance.
    Because of this change at the federal level it is recommended that the states policy be updated to allow those on supervision to consume full spectrum hemp products.
    In order to accommodate this change while making sure that those on supervision are not abusing cannabis it would be helpful to know what sort of thc levels could be expected to show up due to the prolonged authorized use of hemp based cbd products containing >.3% thc.
    Feel free to contact me by email. Thank you for your time.

    1. Hello, I’m looking into using full spectrum CBD oil for daily usage. However, I’m worried about the 0.3% showing up in UA. If you have any info on the THC levels from prolonged use I would greatly appreciate it. I’m employed federally and cannot risk a positive screening, but would like to explore this route for my health conditions.

  86. Micro-dosing or ingesting a small amount <1.0g from a clean state is very hard to detect in urine—unless it is concentrated. Even smoking tough for a few days with +5 or more days to clean out is hard to detect—unless your urine is concentrated. If you build up a reserve of metabolites from moderate to chronic use, then you could be in danger of failing the “lifestyle” test. Drink lots of fluids and exercise your body multiple times a week. Produce more urine more often and youll have less buildup in your kidneys/bladder to exhaust for the test of one deposit of urine. Most elimination rates that have been published rarely surpass over 10/ng per mililiter—per/hr for a rare or one time user. So… dont be a dipshit, dont be impaired at work ever, and moderate consumption and remain active physically, and drink fluids with electrolytes, sugars, vitamins.

  87. Dr. Fudin,

    Thank you for your article and for your time.

    I am in a very confusing situation, that I would like assistance further understanding so that I can more accurately discuss with the individuals I need to.

    In effort to find a non-addictive, non-narcotic consumable that addressed anxiety and joint pain for my mother, I decided to purchase and try two different CBD oils from two different companies. Throughout November I ingested one full dropper (approximately 1.5 mL) of a CBD isolate concentrate daily; this was ineffective for both my mother and I. Thus, I purchased a Full Spectrum CBD Oil (with maximum THC content of 0.3% as allowed by the FDA). I ingested one full dropper (1.5 mL) daily for 10 days; the effects were more noticeable however were not worth the financial cost. Thus, my mother and I both stopped ingesting.

    On 12/4 I willingly went to a medical screening, which included a full-panel drug screen, in an effort to complete necessary requirements for research I am completing at a medical facility. On 12/7 I received an unsettling call from the testing agency. The personnel stated that my urine test came back positive for marijuana, at a level of 24 ng/mL. They tested the urine sample a second time to confirm, with the same results. I was then asked if I am a marijuana user (I am not) or if I have a medical marijuana card (I do not). The personnel told me that it is within my right to have my sample tested a third time at a facility of my choice. To do so, I would need to contact the employer (or in this case the place I am completing research at) to request my urine be tested somewhere else.

    I then contacted both of the CBD oil companies. The isolate was stated to have 0% THC, thus it would be literally impossible for me to have THC in my system from their product. The second company stated that their Full Spectrum CBD Oil did contain THC, at a level of <0.3%. They were very helpful, in stating that sometimes the use of CBD oil can cause a false-positive on marijuana screens, especially when the test is not specific to the THC canabanoid. The founder also stated that he would be willing to have further conversations with the institution I am completing my research at and the school I am studying at, as a failed drug test has potentially severe consequences.

    I am extremely concerned on how and why I tested positive for THC! I have not ingested anything other than these two CBD oil concentrates, and that has only been for 1,000 mL a day) can cause false-positives, along with consuming poppy-seeds, other hemp products, or ibuprofen. I do use a variety of hemp products (both topicals and protein powders, etc.) but it still seems so surprising that I would fail a drug test given the circumstances.

    Your insight into what may have caused a false-positive drug test, given my circumstances, would ease my mind and help me as I have a conversation with the head of research on Monday. I am more than willing to take further tests. I have taken other urine tests in the past 2.5 years for other clinical requirements, and always had negative results. This is very concerning for me.

    Also, any guidance on how to further translate the test results of 24 ng/mL of THC into a quantity of something I consumed, would be helpful.

    Please let me know if you have any questions.


    1. Chelsea, A level of 24ng/mL is quite small. Irrespective of what the companies told you, the amount of THC in their CBD does not have tight quality controls and are not required by law. My presumption is that there was more THC in there than expected. That low of a concentration is indicative of minor use. There are other ways for them to track use and to prove you are not using new doses. They can order a THC and a THC ratio which splits out old and new use.

      1. Dr. Fudin,

        Thank you for your time and quick response.

        Do you think that it is possible that although the company states that they test each CBD oil tincture before they send it out, that they don’t? How would I confirm if they do or not other than by their word and documentation? I do have a little bit of the CBD oil left. Can I independently have it tested?

        The facility that completed the drug screen is not familiar with a THC and a THS ration test. Is it called something else? I will be ordering a third test to be done on the same sample from a facility of my choice. Any aid in requesting the appropriate test and/or the appropriate testing facility would be appreciated. If you know of somewhere in Atlanta I can have the sample sent to, would appreciate the resource.


          1. Do you know of a testing facility I can send the leftover CBD oil concentrate I have, to be tested for THC quantity?


      2. Hey Fubin,
        How long til I pass a drug test if I eat a edible cookie for the first time and haven’t smoked in months?

          1. I have not smoked for over a week, I am a little overweight and when I do smoke I only take two to three hits I never smoke a whole blunt or joint to myself. Will I be okay to drug fest tomorrow ?

        1. My friend has been an heavy everyday dab smoker..he quit exactly 40 days ago and took his test today. Having a cutoff at 50ng and confirmatiory of 15 ng…does he have an chance of passing?

  88. Well.. did some experimenting myself on this topic. I had a single smoking dose of marijuana (roughly 5-6 hits) and approx. 72 after I took a urine test from a local drug store and tested negative for marijuana. The minimum cut off was 50 ng/ml. I sent the results to the lab to get my exact levels. Not sure if they will provide that info but if they do I will update. I am around 6ft, 200 pounds very moderate exercise. Was a moderate user prior but was clean for roughly a month prior to this (job related). Just wanted to thank the researchers on this article because it is very well put together and detailed. Hope this helps other out there.

    1. I am not a heavy or morderate weed smoker. I haven’t smoked weed in maybe 10-11 months. I recently took 5-6 small hits of weed from glass pipe on the 29th of November. I took a drug text for a job on the December 6 in the afternoon around 2 after smashing a a regular bottle of water. i’m in shape. i often run and play basketball sweat at night and eat healthy fruit and fish for the most part. will i pass the test?

  89. Hmmmm I am wondering if this information is really accurate. I honest to god smoked a half of joint of some not so good pot 11 days ago. I took a drug test 3 days ago and tested positive on a home drug test. I am not a moderate smoker. I am a one time smoker and it was still in my system after 8 days.

      1. Dr, I haven’t smoked or consumed in edible form since the 29th of January. I wouldn’t call myself a heavy smoker maybe a few times a week a couple puffs. I am 4 11 and 120. UA on the 26th of February. Will I pass???

  90. There’s a lot of questions unanswered here that can vary depending on your weight and whether you detox your body days before a drug test. I think if you’re a heavy set person that doesn’t exercise or burn any fat then you are more likely to test positive compared to an average size person who eats healthy / detoxes the body and are both moderate users taking an urine test 5 days after consuming THC

  91. I don’t know if Mr. Fudin (or anybody else) is still monitoring this thread but in doing some research, this is the closest I’ve come to any answers to some questions I have.

    I used to be an extremely heavy, chronic smoker for about 15 years. I was never ashamed of it and was always honest with all health care providers regarding my usage. Nobody seemed at all interested. The the opioid epidemic hit. I live in a state where we have the highest overdose death rate in the nation. If anything, doctors were even more accepting of my smoking. They seemed happy that I wasn’t using opiates. Last year, I cut down to a few times a week. Then, in August, 2018, I quit completely (for religious reasons). When I went to my new psychiatrist (old one retired) on 10/23/18, I told him all of this. He said that his practice drug tests every patient and that they have to pass at least 3 tests (for everything) or he will not see them anymore. He said it was required by law (I checked and it isn’t true). I am prescribed an anti-convulsant as a mood stabilizers for Bipolar. He ordered a urine drug test and I went immediately to the lab after leaving his office. He is affiliated with a hospital and the lab is in the hospital. I didn’t think anything of it. Knowing that THC can take a while to clear, I seriously thought it would be okay after 75 days of no use. Nobody has ever given me a hard time over my use. And even if I failed, I have 2 more chances.

    I was shocked when the nurse called the next morning and said that not only was I positive for marijuana, that it was “high”. I asked for a specific number but she just said that it “wasn’t important”. I retired after 20+ years in the legal field so that raised some alarm bells for me. I went to the medical records department and got a copy of my results. In fact, it was a “presumptive positive” for marijuana with no reflex testing and a negative for the anti-convulsant I take for the Bipolar (last dose the morning of my appointment)!!

    I called back and spoke with a nursing supervisor to demand confirmation testing. Not only was I a little upset that this hadn’t been ordered to begin with, I was disturbed that the doctor wasn’t at all worried about the anti-convulsant negative. The nurse said that they never order confirmation testing because it’s too expensive and their lab isn’t set up for it. She said she would talk to the doctor and get back to me but that it was highly unusual for any further testing to be done. At this point, I was concerned about lab error. I called my GP and asked for a written lab order which included reflex testing that I could take to an independent lab. Later, the GP’s nurse called back and said that the doctor didn’t feel that would be appropriate and that I should talk to the psych again to discuss it. My GP is also based out of the same hospital. I got the impression that she didn’t want to step on the psych’s toes by ordering any further testing.

    Today, the psych nurse called and said the doctor was sending an electronic order for a blood test. I went immediately to the lab to have it drawn. Again, the orders were sent electronically so I didn’t know what was ordered until I was in the chair. At that time, the tech told me it was just a marijuana test but that it was being sent to an outside lab and would take 5-7 days to come back. Apparently, still no concern about the negative anti-convulsant result.

    I have researched several medical sources and have found very little specifically related to marijuana blood testing. Everything seems to be about urine screens. In the legal field, we always asked for blood testing with GC/MS. According to case law, it is the gold standard. I guess I’m looking at it from that point of view – we don’t convict people or send them to jail based on a “presumptive positive” so how can doctors make treatment decisions based on that? Then, in the course of my research, I read several articles regarding the uptick in prosecutions for Medicare fraud related to outrageous amounts for claims related to urine drug screens, often when doctors had a financial interest in the lab. Thinking back, my old psychiatrist ordered maybe 2 tests a year (with reflex testing) but they were sent to an independent outside lab. He had no financial interest in them and never had any issue with my marijuana use as long as the anti-convulsant levels stayed steady and I remained stable.

    What are your thoughts on this matter? Specifically, the ethics of basing treatment decisions on a “presumptive positive”? And sending every single patient for a drug screen – including those with no history of substance abuse disorders? Also, is a blood test really better when it comes to detecting drugs such as marijuana? From what I gather, a urine screen can tell you how much they are using but a blood screen is more specific about when they might have used and the level of impairment from it. I admit, I do not like the idea of being made to feel as if I am under suspicion for something. Trust is a two way street. If I am supposed to trust my doctor and follow his recommendations, I expect the same treatment in return.

  92. I haven’t smoke pot in about 10 months. I took one bong hit about 10 days ago I had a drug test today. Pass or fail? Please respond

    1. Did you chief a big hit and enough to get 5/10 stoned from that single hit? If so you’re probably fucked.

  93. Hallo Doctor,
    the police stopped me while driving, and have found the following values in my blood:
    THC 2,3 ng/ml
    THC-COOH 41 ng/ml
    Can I say that I have just smoked once in my life, 3 days before incident?
    Or if you have some advice what I should say. It is important them to believe that I have just smoked once in a lifetime.
    Thanks in advance.

  94. After my sons surgery he stated he tried MJ for pain. I recently had him perform an “At Home” testing kit, which did show a negative result. Are these types of tests reliable or should I have him tested further?

      1. Hi I had a brownie that I didn’t know contained marijuana and it was a horrible experience … I can’t understand why peopywill willing do that to their bodies.. how can I clean that out of my system

    1. Marijuana is generally not harmful or addictive. If he had surgery, he likely tested positive for opiates on the drug test, because he was prescribed opiate painkillers (which can be addictive). I’m confused as to the concern here…. It’s OK for him to take opiates, but you want to test him to make sure he isn’t using marijuana to deal with pain?

  95. I took 2 hits for the first time in 26 years it’s been 8 days I’m sure I’m good will never do it again. My job does randoms just the anxiety of hoping your number isn’t called is agony. Reasure me please so the anxiety can leave

    1. Greg, put your big boy pants on, and go to work. If you get called ur likely to pass and feel stupid for worrying. Don’t use and dont worry, ignorance is the real agony.

  96. Dr. Jeffrey fundin I wanted to know what about if I smoked 27 days ago only one time took 4 hits of vape thc u have had since the drug test I took will i be clean i am 37 yr old Male approx 242 lb and 40 inch waist

  97. Hey, Doc. I took 3 hits of Weed Resin back on the 18th of May, and ONLY THAT. It was a single use. I’ve got a drug test in 4 days, making it about 27 days of staying clean. My weight is about 180 lbs. and my metabolism is average. Should ALL OF IT be out of my system by then? If not, what are my chances of passing?

  98. My urine test was 600ng/ml.
    My employer wants to further my test results to see if I was using within my prescribed mj prescription of 3 grams DAILY. any information on how they could tell. My prescription is 3g a day but does not limit me to THC%. Would that make a difference if I am smoking 25% thc.

  99. People, people. Please. Just read the chart and stop cluttering the comment section with “will I pass?” questions.

    Thank you Dr. Fudin for a great article. It’s often hard to find technical articles that address urine analysis for THC presence.

          1. I had a urine drug test and the carboxy-THC level was 9. What does that mean? I have to retake it n it’s been 2 weeks, I’m just wondering if because it was 9, then I will test negative this time.

  100. What is the baseline for the levels, in urine, after the has left the system?

    3 weeks ago I had a UA and it came back negative. Last week I tested and it came back positive at 26ng/ml.
    So why would it spike after 2weeks? What is the baseline of the ng/ml for testing?

    I know that the test I take has a cutoff of 15ng/ml. But I’m confused and concerned about why it would spike to 26ng/ml. Is 15ng/ml the baseline of thc found in urine?

  101. Dr. Fudin,

    I have been clean 47 days as of 4-4. Light smoker prior to getting clean. I stopped mid January went 17 days then smoked on super bowl. I then was clean 9 days then took one hit and have now gone another 47 days clean. Will I pass a urinalysis?

  102. Hey, Jeffrey Fudin I been ”CLEAN” for a month from weed but I recently smoke 1-2 times yesterday will I pass a drug test?

      1. Dr.Fudin,

        If I was clean for a month and tested clean but smoked for three days about one hit on each of the days will I pass in two week? My body fat is measured around 10.5 percentt and I excersise regularly.

      2. I had 2 chocolate chip cookies containing THC on OCT 8th, had a random urinalysis on OCT 18th. i never use THC. The test came back positive and the number listed beside it showed a 27. how is this possible?

          1. I took a drug test and it came back positive at 15ng/mg at a baseline of 50ng/ml is this a lot? I don’t understand

          2. Hey doc I was clean for about 2 months I took a pretty good drug test and didn’t test positive I smoked again for about 5 days everyday I’m going to do a heavy detox, I work out ,and changed my diet in hope for the pot to be out of my system by the end of the month I have a test Jan 2nd I took a look at the chart and I’m not sure based on my variables

  103. HELP*** I have been a dailie smoker for a few years. I recently quit due to finding out I was going to be drug tested at work for all employees. I have been completely sober for a week in a half. I had my first drug test last Tues and found out my results today. I tested positive for 50 ng of THC. They are giving me a chance to remain 100% absence. I have drank lots of water since. It has been a week now… how long will it remain in my system??

  104. Been clean for 2 months now. Took home drug test with faint lines appearing. Took lab test February 15 I suppose I passed because was not pulled from training. On March 2nd took a hit off a bong. Randomly selected for another lab test on the 7th. Will I be alright? The 8th I took another home drug test with solid lines appearing just to see if I was clean.

  105. I recently was dropped by my doctor of 15+ years and the clinic I’d used for 20+. I had a drug compliance test due to my proscribed narcotics I’ve take for over 20 years, I tested positive with 19ng/ml after not smoking for 10 weeks. I’m told the federal value for a negative result is 15ng/ml. I couldn’t believe it. My doctor knew and while not fully on board allowed me some leeway due to my situation with a divorce, finding myself homeless for months, he allowed me to pick when I had to test would have let me go longer if I’d ask. I truly believed I would pass after such a long time. I don’t know if my story will help anyone else but this is it. So it seems that I am not even allowed to smoke marijuana if I visited a state were it is totally legal. This should be another reason for legalization

    1. We’re you around people smoking marijuana?
      People say “second hand marijuana in a drug test is a myth”. That’s a myth.. A complete joke.

      Did you eat something not knowing it contained the MJ? How much did you smoke before?

      Most likely you were either dropped because you are considered a higher license risk then other patients or your DR finally has done as so many others and got scared started dropping for the smallest things. ESPECIALLY if he/she is not an anesthesiologist or a geriatric/end of life pallative care specialist.

  106. If someone took one hit on October 22 for a friends wedding, which is the first hit in years, and has a hair test today, January 17th, would he pass or fail?

  107. I haven’t smoked weed in a year and messed up and took one hit two and a half weeks ago. I have a hair test next week. Will I pass or fail.

  108. I took literally one hit of high-grade marijuana from a one-hitter 48 days ago. I passed a home dip test after 19 days clean. Q1) does one hit really result in a greater than 50 ng level? Q2) 19 days seems like a long time for one hit to clear, is this abnormal?

  109. What would a 116 ng/ml urine test indicate in terms of amount of usage? Is there any way to tell? The person will not say how often or how recently they last smoked marijuana or vaped cannabis.

    1. I smoked a smoked every night to help me sleep, taking about 3 to 4 hits a night. I tested myself and my numbers were 204, I tested myself 20 days later and they were 152 (it did still occasionally smoke, but not as much) I tested 3 weeks later and was at 108. ( Still occasionally smoking) Oct 2 I was at 39 with a 20ng/ml cut off.

      1. Heavy smokers have been tested positive after 90 days of quitting While regulars dats 3times a week have tested positive after 1month and half. Perfect negative has always been 4month for heavy or rarher daily users.

    2. I’d say a daily user. Half life is 7 days, so in 7 days it’d be half = 63, another 7 = 32ish….I tested at 90 ng/ml & was told 6 weeks to be clean. I smoked everyday, about an eighth a week.

  110. Help! I was approached with a job opportunity and immediately I stopped smoking marijuana. It’s been 36 days and I expected to pass the UA. I signed an offer letter today but they scheduled a hair test (WTF!) For the screening. Before I quit all together I had 2-3 hits a night = about a joint a week for a Good solid month. Before that I did 10 mg a night in edibles for 4 months. I am clean cut so hair is shorter about 3/4″ on top, middle aged with average build. Am I screwed? Just in case I was honest with them about it since they are testing back well before the opportunity came to my attention and my current employer doesn’t test at all and I live in a legal state but they probably won’t care and will want the results.

    1. They usually take the hair from the lower region of your body. They start at your toes and work their way up, until they find a hair to pluck.

  111. My test results was 43 ng/ml under the 50 ng/ml cut off. So why did my sample go on to the 15 ng/ml test and resulted in a positive test since the initial screen was below the 50/

  112. Guys I really screwed up Iv been smoking for 2 months maybe more 2 to 3 times a week and I leave for the navy in 29 days. Please please help me. I’m freaking out and I really screwed up. The cut off is 15 ng

  113. What is the difference between daily users and chronic heavy users illustrated on the table? How many grams of THC or marijuana would differentiate the groups?

    Also, how do think the role of moderate to heavy exercise affect the detection window?

  114. If I took 4 dabs of a vaporizer 2 months ago and this was the first time ever smoking, would I be ok for a UA currently?

  115. Hi!

    I’m stressed. I am definitely not a regular user, but I have smoked 4 times this month…prior to this month it has been months since I have smoked anything. I smoked once in early July, on the 3rd. Nothing the rest of the week, a few puffs about a week later, and yesterday (July 30) smoked like 5 or 6 puffs.

    Now I have a drug test in 9 days. Will I definitely fail?

  116. Okay 13 days ago I took 2 hits of some pretty week shit. Well I have a drug test tomorrow. Will I pass ? I have drink 10 battles of water. I’m 6’0 145 pounds

  117. Hi, I took 5 hits from a pipe 8 days ago, and before that 4 hits from a pipe a week prior. I just had a drug test and line on home drug test came up faint first void day of DT. Will I pass under 50 ng/ml?

  118. Hi,

    the results of my son’s test show the following values:

    6.1 ng/ml THC and
    72 ng/ml THC-COOH.

    Under which circumstances are these values build up?

    Are those values from a regular user? He says he ate brownies a week prior to the test, and smoked a joint the day prior to the test.

    Thank you.

  119. Hello Dr. Fudin,
    I smoked weed about 12-14 days ago and had a drug screening test performed today at a 20 ng/ml cutoff level. I am not a regular smoker, just once or twice a month at most.

    Is there a probability my test will result positive?

    Thank you,

    1. Did you pass? I am passing at 50ng test. After 12 days of smoking. I have a low body fat, HIGH fiber, cardio,sauna and a gallon of water everyday. Does anyone know how long it will take to get to 20ng?

  120. I smoked today and i have BEEN thc clean for 30days and haven’t had it in system today i smoked one bowl 3 puffs will i pass a pee test by next Thursday

  121. Took test on June 23th failed. Got 27 needed 15. Since may 16th I smoke couple one hits. It’s June 26th. How long til I’m clean. Drinking all kinds of water drink unsweetened tea.

  122. So my son tested positive for thc no biggie but his results were greater than 2000 ng/ml what does that mean break it down for me in lamins terms.

  123. My question is, I smoked a marijuana cigarette 5 days ago. Prior to that I’d been clean for a yr. My thing is the hair, the job I’m waiting for takes hair follicles. So will I test positive? I should here back about the job maybe August or September will that give me time?? Help!!!

  124. Smoked a little here and there. Like at most 2-3 days week. Couple hits per day. I haven’t had a hit in 18 days. Took drug test. It was 20ng. Did I pass? Also pretty active and drank lots of water. Workout 3 times a week heavy cardio. Took cleanser -ready Clean too day of test.

  125. You can buy marijuana test strips for about a $1 at Medical Disposables. After 2 or 3 puffs I will test negative in 5 days buy drinking 6 to 8 bottles of water and some moderate daily exercise.

    Good luck.

  126. why try to guess ? Go to your local big chain pharmacy (walgreens, etc) or amazon and buy a home drug test kit. It costs about $10-$15 and you will have a definite answer.

    1. There’s a BIG difference between dip sticks and Gas Chromatography & assays. Especially in a GC w/ Mass Spec. That’s very precise lab equipment that literally costs more then most people make in 2 years.
      Never rely on a strip test result.

  127. So if I took two hits on resin on 420 and had to take a ua with a 20 ng detection level this last Thursday .. think I’m good ?

    1. If you only took two hits of resin and have not been smoking regularly prior to that you will be fine. It all depends though if you were a chronic smoker up until a month ago and smoked dank bud like kush or something then that is a different story.

  128. I just wanted to post this for anyone that needs this. I am a frequent smoker 4 – 5 times a week of high-grade. I stop smoking for 10 days and on the 11th day test NEGATIVE!! All I did was drink a gallon of water EVERYDAY as well as coffee and take a b-12 vitamin everyday! THIS IS FACTS!! I am 5’8 and 145lbs. It can be done, I SWEAR! Just put the time and effort but most of all you got to quit smoking ASAP! Good luck to everyoe and I hope this helps anyone who needs it!

    1. I was a pretty average smoke. When I take the test it will be two weeks. I’m skinny – 26 – fast metabolism – and have been drinking a ton of water and sitting in the sauna. Will I pass a Irvine test?? Please let me know

    2. Your fat holdings are obvioudly less then most people. The thc metabolite is a fat stored molecule. So the less fat the less stored. The metabolites are eliminated over time at what is essentially an a 1 to .5 ratio for stored and waste. 200 stored = 100 potential waste. This is a general idea on elimination and biological factors can lengthen or shorten times.

  129. If I took 5 hits from a weed cigerret 12 days ago.l,what are my chances of passing urin test.after drinking much water and cranberry juice?

    1. If you only smoked those 5 hits that one time you will be able to pass a test with a 50ng/ml cutoff, if the test has a lower cutoff like 20ng/ml I’m not sure.

  130. Well done Mena! Someone get this man a job in pain management!

    To add to your findings, I have seen some chronic, very heavy smokers test + on urine confirmatory testing (much lower cutoff concentration) for up to 80 days after cessation. That’s a lot of pot!

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