It is crucial to keep yourself and your loved ones safe during the COVID-19 outbreak. Yet addiction may pose even a higher danger than the virus.

Learn about recovery during the pandemic:

Niacin Flush Detox Method

Niacin Flush Detox

Important InformationThis information is for educational purposes only. We never invite or suggest the use, production or purchase of any these substances. Addiction Resource and it’s employees, officers, managers, agents, authors, editors, producers, and contributors shall have no direct or indirect liability, obligation, or responsibility to any person or entity for any loss, damage, or adverse consequences alleged to have happened as a consequence of material on this website. See full text of disclaimer.

With drug testing beginning to rise in popularity as a workplace standard, people are starting to look for more and more efficient ways to quickly cleanse their bodies of substances that could make them test positive. Taking niacin has long been a known detox method, but its effectiveness has always been a topic of debate.

Table of Contents

What Niacin Is

Niacin, otherwise known as Vitamin B3 is compound naturally found in a human body that serves the purpose of metabolizing carbohydrates. When it comes to niacin for drug testing, it is usually talked about niacin pills that can be bought in pretty much any pharmacy.
Niacin pills are usually used as a dietary supplement for people who are suffering from high cholesterol levels or low niacin levels, but it is also often used to increase the health of skin, hair and eyes. A niacin pill has around 500mg of niacin in it and the recommended daily dose is up to 2000mg, to prevent the occurrence of negative side effects.

Negative Side Effects of Niacin Pills

  • Skin flushing
  • Burning sensation
  • Swelling
  • Reddening of skin
  • Skin lesions or hives
  • Diarrhea
Help Line Woman

Hope Without Commitment

Find the best treatment options.
Call our free and confidential helpline

Most private insurances accepted

Marketing fee may apply

Niacin Flush

Niacin flush is a method that has been argued to allow a person to successfully clear out traces of metabolites from their body in a shorter amount of time than usual. This is done by increasing the rate at which body breaks down fats, which is where metabolites usually tend to deposit, which in turn allows the person to pass the drug test even though just a short period of time has passed since their last drug use.

The problem with this method is that niacin pills have varying levels of effectiveness from person to person, depending on their height and weight, as well as their metabolism rate. People with higher than average body fat content have reported this method to fail more often than people with lower body fat content.

Another thing to note about this method is that it is not a miracle solution like some people claim and that it has to be done over a period of time, preferably 2 – 5 days for maximum efficiency. This is due to the fact that niacin is very hard on one’s liver and taking large amounts of it (more than 500mg) at once poses a serious health risk.

On the other hand, if the person using this method properly spaces out their dosage (500mg or one pill every 6 hours for 3 or more days) and hydrates plentifully, they pass the drug test in 80% of the reports.

Addiction Resource team does not encourage to use any of the methods for speeding drug cleaning, especially if it is performed for faking or cheating drug screening results.

If Taking Niacin Pills

  • Always space them out at least 5 hours to prevent overdosing.
  • Drink a lot of water, preferably two full glasses with every pill. Also drink as much water, fruit juice, sports drinks or caffeinated drinks during the day, but be careful not to overhydrate oneself.
  • Abstain from drugs and alcohol, to prevent negating the effect of niacin pills.
  • Eat light meals and stay away from fatty foods.

Does Niacin Flush Work?

Despite the fact that many people claim that this method does not work, it usually stems from the fact that the amount of time that the pills were taken for was not sufficient. Taking a large dose of niacin pills in a short period of time, just before a drug test, often cause serious health problems then help pass said test. Only by giving it time will this method have the expected effect without the negative consequences.

  1. Jacobson T. A. A “Hot” Topic in Dyslipidemia Management—“How to Beat a Flush”: Optimizing Niacin Tolerability to Promote Long-term Treatment Adherence and Coronary Disease Prevention. Mayo Clinic Proceedings. 2010; 85(4): 365–379. doi:10.4065/mcp.2009.0535.
  2. Kamanna V. S., Ganji S. H., Kashyap M. L. The mechanism and mitigation of niacin-induced flushing. International Journal of Clinical Practice. 2009; 63(9): 1369–1377. doi:10.1111/j.1742-1241.2009.02099.x.


Leave a comment

  • Jace B
    It works ! I’m about 5’10 & 150lbs . I had to take a drug test and I forgot so when the day came I took three niacin pills , and it worked. However ideally I would have taken two pills for five days up until the day I had to test . However I forgot that’s why I took three.
    • Caleb Larson
      I’m looking at your post man we’re the same height an weight an you only took 3 on the day of the test how long before the test did you take them
      • Curious
        Yeah I would like to know as well, I’ve been taking niacin, pure cranberry juice, and water for 4 days now, I’ve smoked my whole life basically and am worried about my test Wednesday, tmrrw is my last full day I’ve been taking about 3k mg daily for 4 days and have some to take tmrrw and 2 before my urinalysis.
        • Meme
          Did it work?
          • P
            I been taking it for 2 days would it work
        • Anthony
          Does it permanently detox you from thc or is it just for the day of the drug test
      • Gracie
        Did this really work? I just got a job and I took the pills for 3 days straight, I took 2 every 4 hours and drank tons of water, do you think I’ll pass the drug test?
        • K8
          You definitely should. This is crazy and Idk how it worked but once I took 3 literally like 2 hours before a test and somehow it worked. I didn’t even drink that much water. But usually I’ll take 3 and drink a shit ton of water and Powerade and I’ll do that every day for like 2 days. If I have more days to prepare I only take 2 a day.
  • Renee S.
    So I have to pass a drug test Friday, mind you I haven’t smoked in 75 days. I’m 5’6 and 280 pounds. I took one pill and didn’t like the way it made me feel. I think I’ll continue to not indulge and hope for the best.
    • Casreal
      If you haven’t smoked in 75 days there shouldn’t be anything in your system anyways.
      • Cherylynne
    • Jay
      everyone here should remember that the higher the fat percentage in the body, the longer ths stays in your system. Thc lives in your fat cells Niacin can help you lose weight, but it is a MFer! I’l 240 but at one point 280 and Niacin works but be damned careful and keep an eye on your blood pressure. If your heart is in good shape you can press it but you are gonna burn up so bad that you’lll want a bathtub full of cool water around. Ideally, give yourself at least 5 days, but something that is effective is to just take Niacin daily, but not too much excess unless you get desperate, and Iike I have mentioned, it is a desperate act. Just move to Washington, lol!.
      • Jay
        Sorry, the first line is the higher the fat percentage the longer the THC (not ths) stays in your body.
  • Debra D Downey
    I have a drug test on wed I have been taking the. Nican since Friday 1 time a day what do I have to do next plz some tell me
    • Triston Bowie
      Drink water lots of water
      • April
        I have to take a drug test in less than 24 hours but I’m not a heavy smoker and the last time I smoked was 4 days ago. Will the niacin flush work?
        • Bridgette
          Did it work?
      • Tae
        I have to take a drug test next Friday how offen do I have to take the pill and how long do it take to clear your system form weed
      • Allwyn
        Drink 4 8ounce glasses of cranberry juice the night before drink a little vinegar can of green tea a little lemon juice day of rest in morning 1 8 ounce glass cranberry in morning 1 right b4 test don’t drink gre test
  • Gail
    I read an article just before this one that said if a person is to take slow release niacin or to spread the niacin out that that could cause liver damage and that it is better to take them all together at the same time. I find this bit disconcerting and confusing. Sincerely, Gail
    • Paul. Foster
      In highschool I passed 100 percent of my tests. I don’t remember how many I took but it was all at once usually the day or two before the test. Thinking I took 5 Pills at once and had a gallon of water that I downed over the next couple hours.Mind you if you do this please make sure the niacin doesn’t interact with any prescription medications you’re taking. Your face will get super red and is a little painful. Your whole body will feel and look flushed and itch badly for a couple hours.We did this in highschool and I was young and in shape so I guess it depends on a lot of factors. Maybe start off with double what the bottle says and up it from there. Takes about an hour to kick in so be safe if you don’t feel anything. Use at your own risk!
      • elliott
        Exact same to the T
  • Ray
    I only took one niacin pill Sunday and I passed my drug test Monday all I did was drink a gallon and a half of water.
    • Asking ForaFriend
      But were you a heavy “drug” user before the test?
    • Corrie
      For what kind of drug and what kind of test
  • Dexter
    Does niacin flush out from everywhere like hair follicles too.
    • A
      Hair is dead skin cells, so whatever is in them stays in them.
  • Nikki
    Im over 300 pounds if I take niacin right now will it work for a test tomorrow I’ve already been drinking water and about to drink cranberry juice will it work
    • Curious
      Did it work?
  • Charles Mccloud
    I’m 350 will work for me if my test is tomorrow and I started at 4 o’clock this afternoon drinking plenty of water plus niacin
  • Dave
    I’m 6’1 135 w/ only 7% body fat I haven’t smoked in 4 days but only once or twice a day for about a week but it was a dab pen will I pass my test today
  • Theresa Pedraza
    Wondering if it worked if so how many pills did u take and how long did u take them before your test
    • Trasharria Mitchell
  • Mia
    If you used cocaine 72 hours before taking niacin what are my chances of passing a drug test in 24 hours?
    • Casreal
      Cocaine stays in your body 3 to 7 days after last use. If your a heavy user and have a high body mass index (overweight) you can expect for the drug to stay longer.
  • Marilyn
    I need to pass a nicotine cotinine smoking test before my insurance will approve my surgery for Nov. 12. They said I needed to be tobacco free for 30 days. I have fallen off the wagon a couple of times but I have GOT to pass this test NOW. Been drinking lots of water, eating oranges, pure cranberry juice and have not cheated again. Will the niacin help also? I have to clean my system as soon as possible! Any advice will be appreciated.
    • Brenda Escamilla
      I have the same question?? A nurse friend of a friend said she took Niacin as prescribed on bottle and it worked for continine / nicotine test. I have 4 days to get nicotine out of my system. But ive only smoked a couple through out the day. Did it work for you?
  • Ollie
    I’m going to quit drinking what’s good to help flush it out
  • Faith
    If I smoke the day before and then start taking the pills will it still flush it all out in like 3 days.
  • Kniheem
    Okay well I’m 5,4 and like 107 in weight and if I take two of them pills for three days will all the weed get out of my system or do I have to take them before the test?
    • Kenzie
      We’re about the same size. What did you do and did it work for you?
  • Rizarrio
    I’ve passed many drug test using it. I need to know if the non flush works the same way?
    • Mike
      No the non flush will not work and sadly most stores only sell non flush. If you can buy it with flush from Amazon or go to a supplement supply store and buy it from one of those places. But make sure it doesn’t have anything saying non flush
  • Geoffrey Shadley
    I been taking it for like a week I have a test on the 6th will I have to keep taking them or will I be ok to pass it
  • Legend
    I have a drug test on Tuesday and I took one a 12 this afternoon and another one at 3 I already had 41/2 bottles of water do I take more I’m 6’2 and 186 pounds ???
  • Ajizzle
    I am 5’10” 165 lbs with a high metabolism and I won’t have to take my drug test for another three weeks but I have been taking 1 500mg pill of niacin a day for the past four days should I increase the dosage I’m taking to pass in three weeks
  • Tye Roberson
    Does niacin flush your system in one day?
  • Rete
    I have to take a drug test I got called in for at 10:30am Tommrow I took about 5 pills total so far do u think it would work ? What can I do to pass it ?
  • Mmitch
    This stuff is real!!! Just watch your dosage. Do not take more than 500mg on your first dosage. See how your body reacts first. Do not take quick release, you can overdose. You Will experience an uncomfortable heat, itching. Calm down, relax, it will be over in less than an hour. Do not take a shower or bath, in the first hour. You will feel like you are freezing and it just makes it worse. You can take up to 1000mg after your first initial dosage, giving your body time to get use to the Niacin. I had to take a test in 30 to 45 days. I smoked 2-3 blunts a day, for atleast 2 years. That is heavy usage!! Make sure you are drinking a gallon of water per day. I’m 150lbs, so it is recommended to take half of your weight, so that’s about 64 fluid oz’s anyway. Now the water is the real “magic”, It helps naturally clean your blood and system out. Niacin helps clean your blood faster. Exercise, helps get the process of eliminating the drug toxins, But, if your test is within 3-4 days Do Not Exercise, because it will still be bringing the drug toxins out to the surface!! You do not need to take Niacin more than 14 days. But, do continue flushing with water. Depending on your drug frequency, you can definitely pass a drug test within 30 days, if you were not a chronic user ad myself. Also, during this time, You must eat foods like, green veggies, No sugar, Fats, breads, keep your diet simple. This will help you eliminate and cleanse easier. It took me 40 days to see a light colored sign on my drug test. If you don’t consume a lot of weed. It can take less than a week to two weeks. God bless you !! Hope you pass BTW I’m now totally free from my desire to smoke anymore. 2 months this was imaginable. Im getting to old to be going through tjis crap. I feel free again. And, I accomplish much more now.
    • Angel p
      Is there a certain kind niacin to use I’m to pass the drug test I’m hearing different comments an repleys just saying niacin how much to take an milgrams an drink water an other specific fluids an intake some specify niacin flush free im so confused I bought niacin it says flush free on bottle also 500milgram caples but hear there is many brands help me please or is it all the same
  • Lisa
    I smoke weed today sat I quiet for month than wed.thrus.fri.sum day being sat. But I’ve been using nianian everyday for 8 days n 2 day in plenty of water n apple cider vinegar so no smoke tommsun or Mon or Tues wed is the text do u think I’ll pass
    • Curious
      Did it work?
  • Rk
    Have take a drug test on Monday last use of benzos was yesterday not an every day user as well as did little bit of dope again not an everyday day user what’s my chances of passing
  • James Adam Sykes
    My name is Adam and i take xanexs often and im also taking suboxone. Im a Marine Corps Veteran and had to get out of the Marine Corps after doing 2 back to back deployments to Fallujah Iraq. I got out with an honorable discharge. Im 5ft10 my weight is 173. Do you think if i take niacin it will get the Xanax out of my system? I know when my piss test is I go every month but i have popped on 8 piss tests in 8 yrs. Please respond when you get a chance. Thanks
  • Danette Lutrick
    Can takeing niacin and drinking lots of water help me pass a drug screening for thc
  • BLAH
    Niacin definitely works. Ive been passing tests w it for 10 years now to get zs out of my system. I just stop taking them 3 days before the test n start taking niacin (flush-free “Spring Valley” 500mg caps i take). Ill take ATLEAST 2 (1,000mg) every hour for those 3 days before the test. Im prescribed subs n cpins which sometimes becomes a problem becuz it flushes those out too. Ive never failed a test this way. Im just reading comments here now cuz i fuked up n did coke 3 days prior this time. I never touch that shit no more but im a drummer n around it alot so yeah. My test results come back monday so i am praying to god it doesn’t show up. I basically took 30,000mg within 3 days. I didnt have any negative effects like pple r saying. Oh forgot, I am 135-140lbs.
    • Michael
      Work for you?
  • Sue
    I gotta take a drug test on the 6th. When do guys think I should start taking the niacin pills.!?
  • Small person from a small town
    Alright y’all. I’m 5’0 115lbs. Drug test Monday I’m starting my pills today. I’m going to take one every 6 hrs (because I’m small). I’ll be back with the results….
    • Lily
      Did it work ???
  • Experimenting
    This happened last year, but I’m trying it again this year as I have a drug test tomorrow. Last year I was ballsy and smoked the day before the drug test, then proceeded to drink a lot of water (1 L every hour) and took a niacin pill the day of the test, and then drunk more water. Using the trick of not using the first or last streams of pee and more of the middle, I ended up passing. And last year I was a heavy smoker. I’m 5’11 and weigh about 155-160 lbs. I also don’t exercise and smoke cigarettes. It was mostly an experiment for me, but I did pass. I’m hoping for same results tomorrow.
  • Angel Partin
    I have a drug test Wednesday afternoon this monday morning 2.00a.m now my metabolism runs slow at times fast others I have chronic bronchitis an pulmonary lung disease an an my heart is on face most time my body sweats angels like on treadmill most time so I’m in poor health help canine do meth heruonfintenal to by pass pain an to drown in drugs to escape lifes worries an serious depression extreme anxiety an flash backs of a horrific time in my life a victim of raoe assault an an shot an survived I’m sick an I use more than I should but control it maturity time 75% of time I need to pass my drug test for my treatment facility on the verge losing my subutex an thrown out treatment please help I decided I need to pass an leave the toxins out of my life so I can manage my illness an live some quality of life with the worry of extra stressed like this because of my poor choices at this time please tell me what to do I can cancel but be with my meds five six days till I can get in with the sub doc help please thank u desperately needing to pass my test my lifes on the line o.s need best remedy to pass
  • Stacey
    Can anyone confirm a passed drug test from taking flush free niacin?
  • Mileageman
    Okay, Here’s my advice. I take drug tests all the time because I work contract construction and for every new project we have to take a test. First, you people that are taking 3000mg or more in one sitting are taking a big risk of liver damage. Also, you need at least 48 hours and there are other things you can do to help pass. First off, read this article it gives you good information. Take the niacin one pill 4 times a day if you weigh more than 200 lbs then you may want to take 2 pills 3 times a day. This all depends on your metabolism. Also, drink water and juices. I recommend apple cranberry.. just because it has always worked for me. Also, the day of your test, get up early, drink 36 oz water min, take a multivitamin eat a light breakfast like a granola bar and take some b6 like 1500mg and one dose of niacin. You have to take the vitamins or you will fail your test due to excessive dilution. keep drinking water until you pee clear. then make sure you pee at least twice before your test and make sure your pee goes from clear to slightly yellow.. Then you are ready. Also, it’s a good idea to only use mid stream. Never use the beginning. These tips always have worked for me. I am less than average smoker I guess. I smoke about twice to three times a week but only about a gram each. I weigh 180 lbs and am 5’11”
  • Tay
    I weigh 130 I did cocaine yesterday. I have to take a 11 panel drug screen by Friday. Is there any way I can pass the test
  • pm
    I am on probation for a felony charge for 2 years. I messed up and smoked in the beginning and failed 3 drug test. The last test i just took was sometime in jan of 2020 but i still smoked like 4-5 days before my testy. need i mind you this was my last chance or i was getting my probation revoked. I had a friend tell me about these and i went to go buy the ( Nature Made flush free 500 mg). you have to first realize everyone body is different so you can’t expect the same effects. As for me on the first day I took 1 in the morning to see how my body was going to react. I am reading other testimonies to get a idea of what to expect. so what I experience in the hour of side effects is slight itching and sweating area of my body. now some might get hot flashes or cold chills but you just have to try and see. i’m a risk taker so after the side effects left i started taking 3 every hours, same thing happens for a hour but I notice my urine clearing up. not going to lie I got discourage on the 3 day because I was scared they weren’t going to work so I stop taking them. the day of my drug test I took 3 more and when I went to take my test my urine was crystal clear. I passed my drug test not only that I had a drug test 2 days later for a job and I passed that one too! So what i’m saying is that they definitely work just everyone have a different effects to it.
  • Migz
    I haven’t smoked in a week, and I have a drug test tomorrow morning? How should I go about this? I’m 6ft 190
  • Austin
    Im 6’2 240 and have a drug test in 7 days. I havent smoked in almost 26 days and im planning on taking 4 pills a day. Im drinking a little apple cider vinegar with lemon too and drinking a lot of water. Will i be fine oe should i worry
  • Aza
    I have a drug test tomorrow a mouth swob I took 2 pills today do you think I will pass it tomorrow if I take another 2 before bed
  • Hooper Hurst
    That was very helpful. Thank you.
  • blake miffing
    if you have 10 pills of Niacin take 2 pills everyday and drink 10-12 bottles of water and also eat healthy, after about day 2 out of 5 drink more water and it should stay in your system for a day or 2. also if you have it like tmr all you need is 3-5 pills depending on the substance and use of the drug, so if you smoke everyday for like months then most likely you need to take that 5 but if you smoke one time and your test is next week you should not need anything depending if your skinny BUT!!!! if you weigh alot your most likely gonna fail just cause THC sticks to Fat-soluble and your fat… and im not being mean just is what it is, if your skinny your good lol
  • The Helper
    Niacin 100% works. I took it because my recruiter for the military recommended it so I could pass the drug test. I am 6’2 170lbs. You will need at least 3 days for this to work. I would recommend taking at lest 3 pills a day and half a gallon of water a day (at least) for 2 days. What I do is take a pill in the morning, lunch, and dinner. Continuously drink water and nothing but water. Your loss should be clear by lunch. On the third day I take 4 pills just to be sure and consume about a gallon of water. Also I only take the pills up to lunch time on the 3rd day because the piss test can see if you took niacin and can test a false positive. On the day of the test drink as much water as possible so that you can get the niacin out of your system or at least and alarming amounts that can be traced. Ideally I’d say 4 days if you’re a bit larger then me so that you can be sure because thc likes to hang out in your fat. But 3 days should be good enough. Good luck.❤️
  • JayMoney
    I’m 5’6 1/2 weight 186lb I have been smoking like few times last week . I only Took one 500mg Pill & drunk prob 5 bottle of water that same day & had to take the test the next day ! My dawg said I should be good . I wanted know will I still pass ??
  • Haley
    Hey guys! So I just got hired on Tuesday for a job! They never mentioned ANYTHING about a drug test, just a background check. I went in the day after, Wednesday for my background check. I then went in for an 8 hour training on Thursday! They still hadn’t mentioned anything. But while reading the employee guidebook it states that all employees are required to take a pre employment drug screening. My first real shift on the floor is next Thursday. I’ve smoked heavily for years now, and I just recently started slowing down to about 2 or 3 times of not less a day, if at all. Should I be worried about getting tested if the administration hasn’t directly told me I’ll be tested? I’m 6’1” and about 220lbs
  • Dan fitz
    I took 6 today I got a drug screen Thursday the 23rd if I take more would I be able to pass
    • X
      Yes sure u goodyes
  • Nore
    All I do is drink XXX vitamin water right before testing. Haven’t popped positive EVER. 15+ years
  • Angel
    I’ve been taking 3 niacin every 6 hours for 4 days will I pass my drug test
  • Tammy
    I’ve not smoked meth in 7 days & have been drinking lots of water , eating green vegetables and twice a day for a week been taking Niacin capsules 500 mg but on the bottle it says flush for . Will I be able to pass a urine test using these methods ? Please help