How To Pass A Hair Drug Test In 2024 (Without Shaving Your Hair)?

We can all agree that the hair test is the most back-stabbing of all drug tests. Employers are starting to use it more regularly in recent years precisely because it can detect marijuana use up to 90 days after the last joint with decent accuracy, unlike the cheaper urine and saliva drug tests.

Of course, everybody who is faced with a drug test will have to consider how to pass a hair drug test. Not only will not pass the test cost your job; we’re still living in a society that frowns upon marijuana users.

Just because you might have tried weed once (failing a hair drug test) you’re immediately labeled as a slacker or less trustworthy employee and considered more likely to have a dysfunctional job behavior.

We’ll delve into:

  • How long after the last joint can a hair follicle drug test detect THC in your hair?
  • Do you need to worry about a hair test if you’ve only smoked once?
  • How the hair drug test is conducted (how much hair they take and from where)?
  • Most importantly, line out the step-by-step ways of the best methods to help you pass a hair drug test.

It is also important that we outline the methods that don’t work towards passing a hair drug test.

sample of hair for laboratory testing
A hair sample being prepared for laboratory testing.

Contrary to the common belief, just chopping off your hair as well as all the body hair will not trick the hair test; it will, however, look utterly suspicious. And some methods like using peroxide for bleaching the THC out of your hair are outright dangerous.

Let’s address why it might be a bad idea to pass the ever more popular hair drug test, if you even need to worry about not passing the test and what steps you can start making today to successfully pass a hair drug test.

How Long Does THC Stay In Your Hair?

If you have a weed-smoking habit or if you’ve just touched a joint once, you will likely want to know how long does weed stay in your hair follicles. After all, we’re all faced with the same hair drug testing techniques and the results are measured as:

  • Positive.
  • Negative.

There is no middle ground; a guy who smoked 1 joint in the last few months can be as positive on a hair drug test as the guy who smoked 100 joints. What differs between a regular user and a one-time marijuana user is the likelihood the THC in hair will be detected.

How fast does the THC reach the hair?

In simplified terms, the THC can be detected in hair from 5 to 90 days after the last use.

The good thing is that the THC isn’t detectable in hair after 5-7 days after the marijuana use because it takes about a week for an active ingredient in marijuana (THC) to reach the hair.

How Does THC Even Reach The Hair From Smoking Or Edibles?

The active ingredient in marijuana takes about a week. Here is the step-by-step physiological process of how does THC in marijuana even reached the hair follicles and starts to enter into the new hair:

  1. THC in marijuana must cross from lungs (joints, bongs) or small intestines (marijuana edibles) to the bloodstream.
  2. From there it moves throughout the body and eventually reaches hair follicles via small capillary blood vessels.
  3. The THC is deposited in the hair follicle.
  4. When the hair grows, the marijuana in the hair follicle is transported from the hair follicle to the newly grown hair (where it can be detected via hair drug tests).

The hair growth is slow (hair grows about half an inch per month) and we can only detect marijuana in hair grown from a THC-rich hair follicle. This is the reason why your hair drug might be negative even if you smoked 10 spliffs the day before the hair drug test (given that you’ve been clean before, of course).

However, the single biggest factor in determining if you will test positive in a hair drug test, besides when you used marijuana last, is the amount of THC you’ve used in the last 90 days.

Can Hair Drug Test Detect One Time Use?

Of all the marijuana users, usually the most petrified about drug testing are the one time users. The following conclusion of the article ‘Comparison of cannabinoids in hair‘, published by the Drug And Alcohol Review, does shed some light on if a one-time user will test positive for THC on a hair drug test:

Hair analysis can be used as a qualitative indicator of heavy (daily or near daily) cannabis consumption within the past 3 months. However, this approach is unable to reliably detect light cannabis consumption or determine the quantity of cannabis used by the individual. (2017 Cannabinoids in hair study)

According to the study, everybody who uses marijuana once a week or less is considered a light user. According to the study, 39% of hair samples gathered from the pool of light marijuana users were positive for THC. In short, there is quite a significant chance that somebody who uses marijuana only occasionally might test positive in a THC hair drug test.

What if I only smoked a single joint (or even less)?

Unfortunately, even super-light users have to worry about testing positive for marijuana in their hair. Given the academic research, the likelihood of testing positive for a one-time user (in the last 5 to 90 days) is between 0% and 39%.

Granted, the likelihood of getting caught on a hair drug test is considerably lower than for heavy users but it is not zero.

Do Your Own Hair Drug Test Before Facing The Real Lab One

But don’t just start cutting off your hair right away. Given the probability, it is likely that 9 out of 10 one-time marijuana users will test negative in a drug test. One way to make sure you’re not the unlucky 1 out of 10 who would fail a drug test is to test your hair yourself prior to doing anything else.

You should look for DIY hair drug tests with a good reputation. One great example is the Hair Confirm 90-day test where you basically buy the kit, collect your hair sample and send it to the laboratory with the included pre-paid envelope. The CLIA approved lab tests your hair thoroughly with two methods (radioimmunoassay screen and gas chromatography/mass spectrometry (GC/MS)) and you’ll get a result in 2-3 business days.

Most of the one-time smokers don’t want to leave anything to chance knowing full well the stain on their reputation a positive hair test would leave. If the lab confirms that your hair is positive for THC, you should proceed down to the section where we talk about the effective methods of how to pass a hair drug test.

Why Does It Take 90 Days For The THC To Leave The Hair?

With most of the other drug tests, THC cannot be detected after about a month. However, with the hair drug test laboratories can detect drug use up to 90 days after the last use.

The 90-day time interval is also the reason why employers are opting for a hair drug test for their new hires. The urine and saliva drug tests are cheaper but can’t really tell with any certainty if a new employee has used marijuana in the past 80-90 days.

We’ve covered how the THC is absorbed into the bloodstream via the lungs and is deposited in the hair follicles from where it can move into the newly grown hair.

What is essential to understand is that the THC doesn’t stay in the hair indefinitely. The molecule is slowly washed out of the hair on a daily basis. Research shows that in about 90 days the amount of THC in the newly grown hair is no longer detectable. For all intents and purposes that means that there is no more THC in your hair.

In fact, the best methods of how to pass a hair drug test are successful primarily because they exponentially increase the flow of THC out of your hair.

Of course, regularly washing your hair with a standard shampoo does help a bit but it is quite insignificant compared to the effect the specialized anti-hair drug test has on THC hair elimination.

How Is A Hair Drug Test Conducted At The Laboratory?

When your employers or HR department instructs you to take a hair drug test, they usually don’t inform you of what is the process about. They give you the date and place when and where you have to appear and leave the rest to the laboratory personnel.

If you’re taking the hair drug test for the first time, it makes sense to inform yourself of what you can expect; essentially what will happen when you arrive at the hair drug testing laboratory.

That why we will outline the step-by-step hair drug testing protocol that most of the technicians are currently following:

Step 1: Donor Identification And Preparation Of Hair Sampling Materials

The hair drug testing procedure beings when you arrive at the laboratory. The first order of business is to accurately identify who you as a hair sample donor are and review the employer’s paperwork (via checking employer ID number).

This is done by a laboratory technician or a medical nurse.

Remember to have your personal ID card with a photo with you; all the information, including your personal photo, is the basis for identification.

In the first step, the hair drug testing technician has filled out the types of test and specimen that is to be collected and well as note down the reason for a hair drug test.

Additionally, all the sampling materials have to be disinfected and ready. In the case of a hair drug test, that simply means that a nurse or technician will clean the scissors which will be used to cut your hair (collect the donor’s hair sample).

Step 2: Collecting The Hair Sample

Collecting the hair for a drug test is the crucial step and therefore the technicians performing the sampling have quite specific directions on exactly how much hair to collect and from which part of the body.

The most obvious choice is the hair on your head. For a successful hair drug test, it is essential for the hair to be cut as close to the scalp as possible. Depending on the drug testing facility, they will collect anywhere from 100 to 200 hairs from all over your head (with the exception of bald spots, obviously).

How long should the hair drug samples be?

The standard is to collect 1.5-inch long hair.

Of course, the obvious question is what if you don’t have hair that long? If your hair is less than 1 inch in length, or if you don’t have any hair on the head, the drug testing expert will collect hair from other areas of your body.

That usually means the scissors will befall your chest hair, underarm hair, the hair on your legs, or even, yes, your beard. If you don’t have enough hair under your armpit, for example, the technician can take hair partly from other parts of your body, with the exception of the head hair. That’s because the methodology is evaluating if THC or THC residues are present in body hair vs. head hair is a bit different.

Step 3: Preparing The Collected Hair Sample For Testing (Radioimmunoassay Or GC/MS Detection)

This is the step where the hair sample donors have done their job and the real hair drug testing work beings.

The collected hair specimens are carefully and methodically placed on a sort of hair drug testing foil, according to the laboratory’s protocol. The arranging of hair samples is quite a meticulous job but as a donor, you don’t really see that part nor do you see the part where your drug sample is transferred to the laboratory’s analytics equipment.

One important point when you’re finished is to know that you nor your company will get the results of hair drug testing immediately.

It usually takes a few days for the hair to be tested and all the paperwork done properly. Sometimes the new hires don’t get feedback from an employer about their hair drug test in a week’s time and are starting to get worried. Again, this is not an indication that you have failed a very important drug test; it’s rather that the results from a hair drug testing facility take a bit longer to be processed and presented to you.

Methods Of How To Pass A Hair Drug Test Faster

Anybody who hasn’t smoked weed in the last 3 months will pass a hair drug test (or at least, he or she has a very high probability of passing the dreaded test).

Methods of passing a drug test quickly should really only concern people who have smoked weed in the last 3 months and don’t really want their employers to find out. Despite weed being legalized at a quick pace, the employers are still lagging behind the legalization and you will be more likely than not ostracized or fired/not hired if you fail a drug test.

Because so much is at stake (job, family, lifestyle) it makes sense that most of the people faced with a hair drug test would do pretty much anything to pass it.

This urgency gave birth to all kinds of methods on how to beat a hair drug test, both legitimate as well as those which will more likely ruin your chances of passing a drug test (or having a decent haircut in the recent future).

Because we want to seed out all the urban techniques that supposedly help you pass a hair drug test, we’ll cover both the methods that don’t work (or are at least questionable) as well as the successful and tested method.

However, make no mistake: with the right approach, it is very likely that you will have no problems passing a hair drug test.

Collection Of Methods That Don’t Help You Pass A Drug Test

Being cornered by a hair drug test will make people do crazy things. Here is the list of some methods (but not all, there is a sea of misinformation out there) that can’t help you pass a drug test

Completely Cutting Your Hair

Let’s start with the first and obvious one: “I’ll just cut all my hair, armpits, and chest hair as well.”

There is no scarcity of both light and heavy marijuana users who would even sacrifice their 6-months old beard to pass a drug test.

Will cutting all your hair help you pass a drug test?

No. If you follow the protocol of how hair samples are collected, you’ll notice the obvious truth: No hair equals no hair testing. You’re not beating a hair drug test; at best, you’re completely avoiding it.

Honestly, being impervious to hair drug testing is not without its merits. If they can’t test you, they can’t find out you were using drugs, right? However, there are two things to consider:

  1. Wouldn’t it look utterly suspicious if you would cut your hair a day before an important hair drug test? What would your potential employer make of this?
  2. The hair drug test is not the only one. Will a suspicion you’re using marijuana arise enough to face the virtually unbeatable blood drug test?

The suspiciousness alone can be enough for you not to get hired. Moreover, if the HR department decides that since your potential drug use can’t be tested with a hair drug test on account of you not having hair (which is, well, weird in itself), you should be tested with other methods.

That leaves the cheaper urine drug test and saliva drug test that will only show if you’ve been using marijuana in the last 30 days. That would be a gift, however.

When the HR becomes suspicious, they might just opt for the blood drug test. Admittedly, it’s more expensive for the company but it will detect marijuana use in the last 6 months. Contrary to the hair drug test where we have successful shampoos we can use, there is no method whatsoever that might help you if you’re faced with a blood drug test.

Peroxide – Will Bleaching Your Hair Help Get THC Out?

Many laboratory technicians that specialize in hair drug testing will tell you that they see more blondes than a hairdresser.

Unfortunately, people still use hydrogen peroxide, a somewhat toxic chemical, to bleach their hair in preparation for a hair drug test. Performing the bleaching on your own can be dangerous to your hair, face, and eyes, to say the least.

The logic for using peroxide is that it just ‘washes’ the THC out of your hair. This is not entirely accurate; the aggressive hydrogen peroxide does damage the outer layer of hair (called cuticula) through which the THC can escape more easily.

Basically, it’s like poking microholes in your hair and spill the THC out of the hair strands. Admittedly, this does help reduce the time of how long marijuana can be detected in your hair but it comes with two very important warnings:

  1. It’s (freaking) dangerous if you’re using a higher concentration of peroxide. You can ruin your hair or even bleach out your eye if you’re not careful.
  2. Using peroxide has a considerable effect but it’s often too little too late.

Researchers from Spain’s National Institute For Toxicology have demonstrated that dying (with the use of peroxide) can decrease the amount of THC in the hair by 40-60%.

In most cases, this is not enough to pass a hair drug test.

Additionally, using hydrogen peroxide is alike to a ‘brute force attack’ on your hair. It would make sense if we didn’t have a friendlier and more efficient want of washing the THC out of the hair strands (explained in the section of preferable methods).

Internet Myth Practices Like Marujo Method And Jerry G Method

Over the years, various people have proposed methods of how to pass a drug test. These methods are not particularly science-heavy; they’re based on more or less personal experience of individuals that have passed a hair drug test.

We’ll cover only two of the most popular methods and would reserve our scientific judgment if they actually help you to pass a drug test.

The mentality here goes along the way of ‘What can I use in my kitchen to pass a drug test’:

1. Jerry G Method With Baking Soda

Baking soda is an all-time favorite kitchen thing to use for home experiments. Incidentally, somebody that went by a user name ‘Jerry G’ in 2008 had a story to tell about how he used baking soda to pass a hair drug test.

This ‘G man’ method is surprisingly (suspicious?) simple:

  1. Made a baking soda paste and soak your hair in it for 30 minutes.
  2. Bleach your hair 2-3 times.
  3. Use Zydot Ultra Clear shampoo a day before the test and you’re scot-free.

The stories of how the Jerry G method works are quite plentiful.

2. Macujo Method With Vinegar

While baking soda is a more basic (as in pH level over 7) approach to passing a drug test, the Macujo method is your acid-friendly method with an added bonus: you can even risk a bit with laundry detergent.

Here is how the Macujo method work (for everybody who likes to put some dangerous chemical on your hair):

  1. Take some vinegar and soak your hair in it for 30 minutes.
  2. Wash out, and follow with a Clean and Clear astringent and soak your hair in it for 30 minutes.
  3. Wash out, and soak your hair with Tide laundry detergent (we’re not even kidding, this is the Macujo method in its finest).
  4. End by soaking your hair in good-old baking soda paste for 30 minutes.

All in all, these internet myth methods do sound dangerous and have the questionable effect of actually passing a hair drug test but for better or worse people are still using them.

Let’s rather concentrate on simple methods that do work:

The Best (And Simplest) Methods To Pass A Hair Drug Test

Admittedly, passing a hair drug test might seem tricky because you know the THC and its metabolite THC-COOH is literally inside your hair. The question of how to get is out is obvious and the answer is quite simple:

You have to wash the THC out of the insides of your hair strands. Passing a hair drug test does take a certain amount of dedication and effort.

The good news is that everybody can pass a hair drug test surprisingly well without using some ridiculous methods including baking soda, vinegar, peroxide, or even without cutting all your hair.

The most effective way of getting THC out of your hair for preparation for a drug test is by both:

  1. Washing your hair like crazy several times per day.
  2. Using specialized penetrating shampoos that dissolve the THC build-up in your hair and exponentially eliminate it out of your hair strands. Every with the best Old Style Aloe Toxin Rid shampoo you have to wash your hair at least 15 times before giving a hair sample.

Everybody can wash their hair several times per day. However, the truly effective part of every method to wash out the THC is the right choice of specialized shampoo. The best way, of course, is to use the combination of the two best shampoos that have the deepest penetration and extract the THC from hair strands the fastest.

There are basically two types of shampoos:

  1. Light-duty Zydot Ultra Clean shampoo for everybody who smokes just one joint in the past 90 days.
  2. Heavy-duty Old Style Aloe Toxin Rid shampoo for heavier users (basically everybody who has smoked 3 or more joints in the last 5 to 90 days). You can check out the full review of Old Style Aloe Toxin Rid shampoo here.

Needless to say, the safest course of action for everybody who has a lot to lose if he or she fails a drug test is to use both of them as a combination.

Of course, if you have to choose just one, go for Old Style Aloe Toxin Rid shampoo. It does cost considerably more than vinegar or baking soda; however, it has one very important advantage: it actually works.

How To Use The Most Successful Hair Drug Test Shampoo Duo (Starting 10 Days Before The Test)

The main part of the two-shampoo plan is, of course, the Old Style Aloe Toxin Rid shampoo. The Zydot Ultra Clean shampoo serves as a finishing touch to present completely THC-free hair on the day of the test.

This is how the best way of passing a hair drug test looks like in a step-by-step form (you should start with this about 3-10 days prior to the test):

  1. Use normal hair shampoo to clean the cuticula (the outer part) of hair strands.
  2. Apply the Old Style Aloe Toxin Rid shampoo; make sure that you by rinsing reach the base of every hair.
  3. Leave the Old Style shampoo on for 10 to 15 minutes. Getting THC out of your hair is a somewhat lengthy process.
  4. Rinse out and repeat about 2 to 3 times per day.

Ideally, you should wash out your hair thoroughly using the Old Style Aloe Toxin Rid shampoo at least 15 times before a drug test.

To complete the whole washing process and guarantee yourself the best chances possible to pass a drug test you should use the Zydot Ultra Clean shampoo to wash your hair on the day of the test.

How About If You’re Not Certain If You Even Need To Detox Your Hair For A Drug Test?

The most annoying thing is when you’re not actually sure if you need to do something about getting the THC out of your hair or will you pass a drug test without doing anything.

As always, you can leave us a comment, something along the lines “Hi, I’m 168 lbs 6’2” male and I haven’t smoked for 72 days, have a drug test in 2 days, will I pass?”

Using our ‘help a brother out’ motto we’ll give you an estimate of how likely it is for you with your specific situation to pass a drug test. However, as always the problem with the hair test is that without performing a test, it’s really impossible to say with a high degree of certainty.

You can always check yourself using the Hair Confirm 90-day test to make a sample of your hair and get the results before you start washing your hair like crazy.

Hopefully, the employees will pick out the weed legalization means that society is more accepting of marijuana use and that eventually, society won’t look down on people who recreationally use marijuana in their everyday life.

Best of luck.

Studies And Sources:
  1. Taylor M, Lees R, Henderson G, Lingford-Hughes A, Macleod J, Sullivan J, Hickman 2. Comparison of cannabinoids in hair with self-reported cannabis consumption in heavy, light and non-cannabis users. Drug And Alcohol Review. 2017 Mar;36(2):220-226.
  2. Jurado C, Kintz P, Menéndez M, Repetto M. Influence of the cosmetic treatment of hair on drug testing. International Journal Of Legal Medicine. 1997;110(3):159-63.
  3. Huestis MA, Gustafson RA, Moolchan ET, et al. Cannabinoid concentrations in hair from documented cannabis users. Forensic Sci Int. 2007;169(2-3):129–136.
  4. Moosmann B, Roth N, Auwärter V. Finding cannabinoids in hair does not prove cannabis consumption. Sci Rep. 2015;5:14906. Published 2015 Oct 7.

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