How to Pass a Hair Drug Test

We’re not going to beat around the bush here. When it comes to drug tests, a hair follicle drug test is extremely hard to beat. So, how to pass a hair drug test? It can be done, but you’ll need some time and some specialised products to give you the best chance of passing. So if your dream job is depending on you passing a hair test, here’s everything you need to know.

Hair follicle testing has been gaining popularity over the last couple of years. There are several reasons for this:

  • Hair tests detect a longer history of use: Other drug tests, such as urine and blood, are only good for detecting use over a few weeks or months.
  • Hair tests are harder to cheat: Because there are no privacy issues, a sample can be collected in full view. So, unlike urine or mouth swab tests, it’s harder to tamper with the sample before collection.
  • Hair tests are extremely sensitive and accurate: The threshold levels for follicle testing are extremely low and there is a long window of detection with these tests.

Although marijuana can be detected in hair about 5 – 7 days after use (assuming you’re a first time user), it’s more reliable for detecting a history of usage. Should it really make a difference to your employer if you smoked marijuana some months ago, even though you’re not currently using? That’s up for debate.

Marijuana and Your Hair

how to pass a hair drug test

Hair drug testing is among the toughest tests to pass.

First, let’s explain how the tetrahydocannabinnol (THC) gets into your hair. When you smoke or ingest marijuana, the active ingredient that’s responsible for the high you get, called THC, gets into your blood stream. The blood takes it to the liver where it gets broken down into metabolites.

It’s one of these metabolites, specifically THC COOH, that drug tests screen for as an indicator for marijuana use. Unfortunately, THC COOH cannot be dissolved in water. So your body stores it in fatty tissue, slowly releasing small amounts back into your system. Eventually, your body gets rid of it through your faeces and urine.

Why does this affect your hair? Because your hair needs blood to grow. And it gets this blood from the root at the base of the follicle. That’s where it picks up THC and other toxins. They literally become trapped in your hair as it grows out.

Hair tests are also far more sensitive than blood, urine and saliva tests. All tests screen for the concentration of THC, which is expressed in nanograms per millilitre (ng/ml). The cut-off point usually falls between 20ng/ml – 50ng/ml. A higher result means the sample will be sent for further testing to confirm the result.

But hair tests can detect as little as 1ng/ml. The threshold may vary between labs, but in general, when it comes to hair tests, it’s extremely low. If you know what lab your sample will be sent to, do some research on them and find out as much as you can about their methods.

How Does a Hair Follicle Test Work?

A small sample of hair, close to the scalp will be taken from the back of your head. Only 1.5 inches of the freshest growth will be used for the test. This is enough to give a three-month history. Because hair grows at an average rate on 0.5 inches a month, this is all the lab needs.

hair follicle

This is a hair follicle.

If you’re bald, or your hair is too short, body hair can be used instead. Hair tests can detect drug use for as long as a year prior, but accurate results are generally limited to 90 days. A hair test can even give a rough estimate of when someone was using drugs. This is because hair grows at such a steady rate. But this information isn’t disclosed in the results your employer gets.

At the lab, the hair is washed with chemicals. This is done to remove the residue from any outside contact with drugs and reduce the possibility of a false-positive. The results are normally available within three days.

Hair follicle tests were originally designed to determine if someone was a long-term, heavy drug user. But, because the test is so sensitive and is able to determine a history of marijuana use, even occasional pot smokers will test positive.

How to Pass a Hair Drug Test

So how do you pass a hair drug test, apart from not using for at least 3 – 4 months before your test? Well, regular detoxing methods won’t be much help now. But it’s a good idea to stop using marijuana right away. If the hair test doesn’t work out for some reason, you may have to take another kind of test. So it’s best to prepare yourself as much as possible.

What you’ll need to focus on now, is working on your hair to bust those metabolites that will give you away. The process can be hard on your hair, but it’s the only way. You may also need a few days of treatment to give yourself the best chance of passing. So, the sooner you can start the better.

Detox Shampoos

aloe rid

Aloe Rid (old forumla).

They aren’t cheap, but if you need to pass the test to get a job, consider it money well spent. The two shampoos listed below are the most reliable when it comes to passing a hair test. There are others on the market that you could use, but do some research and always check the reviews

Remember that labs are aware that people will try to find ways to cheat. So they are constantly improving their tests to make them harder to cheat. What has worked for people in the past may not get past the lab’s scrutiny now. So look for the most recent reviews to make sure you’re not wasting your time and money and risking your job.

  • Aloe Rid (old formula): This is one of the best detoxing shampoos available. Hundreds of people have used it successfully. But it’s vital that you get the old formula. The new formula simply doesn’t work. Luckily, Test Clear still has the old formula available, but supply is limited. It’s expensive, but it’s the most reliable shampoo you can use for detoxing your hair. You’ll need to use it at least 3 – 10 days before your test. If you don’t have that much time, then you’ll need to wash your hair with it at least several times a day before your test. For best results you should use it together with Ultra Clean.
  • Ultra Clean: Although this shampoo is also popular, it’s not enough on its own. You need to use it with the Aloe Rid to improve your chances. It combines a shampoo, purifier and conditioner in one, so your hair doesn’t look dried out and damaged. This is the shampoo you should use on the day of your test to ensure you pass.

There are other brands available that may work, but the two recommended above have a long history of success—especially when used together. Many shampoos are labelled as “detox shampoos,” but often this is nothing more than a label designed to sell it. They’re not that different from normal shampoos and won’t help you pass your test. So always research before you buy.

The Macujo Method

You might have heard of the Macujo method on social media and in forums. It’s popular with many marijuana users because it’s possibly the most effective method of passing a hair test. It’s been around for a long time, since the early 2000s. But people don’t often share this information so it’s possible you haven’t heard of it.

Like most of the methods, it can be hard on your hair and your scalp. If you decide to try it, take extra care to moisturize your hair and skin as much as possible. In fact, you want to cut your hair once the test is over and you’ve got the job.  A little irritation is a small price to pay for a negative result, but you don’t want to do any serious damage.

You’ll need the following ingredients for the Macujo method:

  • Nexus Aloe Rid Shampoo: Again, make sure you have the old formula. It contains propylene glycol, a solvent which can open the hair shaft and remove the toxins from your hair.
  • A shampoo with salicylic acid. A good one is Neutrogena’s T/Sal Therapeutic Shampoo. It contains about 3% salicylic acid in 4.5fl oz.
  • Liquid washing detergent. A brand like Tide is good, but any similar product from your local grocery store should do the job.
  • White vinegar: Again, a brand like Heinz is good, but any brand of white vinegar should work just as well.
  • Shower caps: They’re cheap so buy a bulk pack—you’ll need them.
  • Goggles: Things can get messy so make sure your eyes are protected.



The Macujo method has eight steps to follow.

If possible, start doing this once a day for 9 – 10 days before your test. If you don’t have that much time, then you can do it twice a day at least 5 days before your test.

  1. Wet your hair with warm water. This helps to open up your hair shaft.
  2. Use the vinegar and massage it into your hair and all the way down into you scalp. Make sure you don’t get it in your eyes.
  3. Now put the goggles on. Use the Neutrogena T/Sal shampoo and wash your hair and scalp with it. This will probably burn your skin a bit. Wipe down any exposed areas such as your ears, eyebrows and forehead.
  4. Put a shower cap on and leave the shampoo on your hair for at least 30 – 40 minutes. You’ll want to keep a towel handy to wipe up any drips that escape.
  5. Once the time has passed, rinse your hair thoroughly.
  6. Now use the Aloe Rid Shampoo and wash your hair with it at least twice.
  7. Finally, take a small amount of the liquid washing detergent and wash your hair until it squeaks.
  8. After about an hour, you can use a conditioner on your hair to restore some moisture.

Finally, don’t forget to use the Ultra Clean to wash your hair on the day of your test.

The aim of this process is to open your hair shaft up so that you can wash the evidence of your marijuana use away. There may be some other methods involving bleaching and dyeing your hair more than once before the test, but this is extreme and will do a lot of damage. It will also look highly suspicious.

Home Testing Kits

You can use one of these to test your progress and see if your detoxing is working. Unlike urine and saliva tests that you can do yourself, you’ll need to send your hair sample to a lab for testing. So it will be a few days before you get the results. And that’s also why they cost more.

A brand that we can recommend is Hair Confirm which is sold by Test Clear. Once you get it, just place a sample of your hair in the envelope provided and send it off to the lab. The address is printed on the envelope and shipping is pre-paid. In a few days, you’ll get your results.

And best of all, everything is anonymous, so there’s no risk that of anyone knowing what you’re doing.

Alternatives to Detoxing

Honestly, your only other option is to shave your entire body. Remember that any kind of hair can be used for a hair follicle test. Leg hair, armpit hair, chest hair and even beard hair can be used to provide a sample. But shaving your entire body would be difficult and only make you look suspicious.

Even if you could get away with shaving your hair (especially if you’re a guy), it wouldn’t look good if you had a full head of hair before you were told about the drug test, would it?

Finally, it might help you to know that hair follicle tests are more likely to detect regular, rather than occasional marijuana use. A study has shown that at least 85% of daily users test positive; versus 52% of people who only smoke 1 – 5 times a week. But long-term use means you’ll have accumulated higher levels of THC in your system. So, why take the risk? Use the products and methods we’ve recommended here and increase your chances of passing your test.

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