Fraser Horton
Fraser Horton
Last Updated on July 13, 2021

Drug testing in the workplace is much more common nowadays than it used to be and it’s also becoming a frequent prerequisite for job applications.

For non-users, a drug test wouldn’t be a big deal, but for cannabis users, it can be disconcerting, and understandably so because it can cost them their source of income. Marijuana is still federally illegal, despite the legalization in most states, so many employers treat it as such.

By far, urine drug tests are the most commonly used because they’re inexpensive and pretty accurate. However, hair testing, although not as commonly used, is gaining favor over other types of drug testing because it’s the most accurate, and its detection window is much longer compared to other tests. Additionally, it’s the hardest to pass.

However, many people claim that there are ways you can get THC out of your hair, or at least render it undetectable by the test if you have an upcoming appointment.

In this article, we’ll explain how the hair strand test works and what methods are commonly used in the weed community to lower the traces of THC (tetrahydrocannabinol) in the hair. But of course, we are not recommending cheating your way out of a drug test – so the content of this article is purely for educational purposes only.

How Does THC Get In the Hair Shaft?

When you consume weed, the cannabinoids (THC and CBD) first get into your bloodstream, and then they get carried to the liver where they get broken down into byproducts. From there, the byproducts, also called metabolites, get stored in the body fat because they are fat-soluble.

THC metabolites mainly get deposited into the hair shaft through the sebaceous glands on the scalp that secrete a natural oil called sebum to protect the scalp from overdrying. Only a small portion of the THC metabolites get to the hair shaft from the bloodstream. 

As your hair grows from the hair follicle, the THC metabolites become incorporated into the structure of the hair strands. It usually takes 5 to 10 days for the metabolites to reach the scalp surface and be incorporated into new growing hair strands.

This is why hair follicle drug tests are so accurate – THC literally becomes a part of your hair. This, however, doesn’t happen only with THC but also with any other drug or medication. So, as you can see, your hair strands contain the history of your cannabis consumption, which is the reason why these tests are used to detect habitual drug use. 

Most tests look at the past 90 days of drug use, but some employers may order tests that go further back in time, like 6 or 9 months. However, due to environmental changes and chemicals in the hair, the test loses its accuracy beyond the 90-day mark.

How Does Hair Follicle Drug Testing Work?

The hair follicle drug test is designed to detect one particular THC metabolite called THC-COOH at a minute concentration of 50 ng/ml (nanograms per milliliter). Since the cutoff level is very low, the test is very sensitive, and therefore accurate.

Testing labs will need a small sample of hair that will be cut off from the top or the back of your head close to the scalp. The hair sample will be 1.5 inches in length because human hair grows about 0.5 inches every month, so 1.5 inches of hair would cover a period of 90 days.

If you shave your head or are naturally bald, you will be asked to provide a sample of body hair.

Hair Testing In Comparison to Other Types of Drug Tests

The biggest difference between the different types of drug tests is the detection time. The hair follicle drug test has the longest detection window among all types of drug tests and it’s used to detect habitual drug use. The urine test may be the most commonly used, but it only detects recent drug use, from 3 days up to 30 days. Saliva tests can detect THC within 72 hours, while blood tests have the shortest detection window of just 4 hours.

Commonly Used Methods for Getting THC Metabolites Out of the Hair

The most obvious solution would be to abstain from consuming weed long enough, or until your new hair growth is free from THC metabolites. 

However, the time frame for a natural THC detoxification is at least 110 days for occasional to regular users, and over 150 days for heavy users, and in most cases, drug tests are announced only a few weeks in advance. Ceasing your cannabis use immediately is always recommended, but people often look for alternative solutions, like detox products.

Are There Any Detox Products That Can Help?

That said, there aren’t that many detox products for the removal of THC metabolites for hair drug tests like there are for urine tests, like detox drinks and detox kits. However, there are two very well-known methods going around the cannabis community. These methods have been on the internet after blowing up in the early 2000s and are still much discussed on online community forums. 

While there is no scientific proof of their efficacy because no studies have been conducted, there are a number of anecdotal stories of people claiming that these methods were successful for them. That being said, it’s best to take these claims with a grain of salt.

Please take note that the hair follicle drug test is the most accurate drug test currently available, but we do not recommend trying to cheat it. Bypassing the law may bring serious repercussions, especially if you live in a state where cannabis is still illegal. The methods described below are purely for informational purposes, so please proceed with that in mind.

The Macujo Method

For this method, you’ll need several different products such as detox shampoo, detergent, and facial astringent, among others, which you can easily find online or in a drugstore.

Many people claim that this method has worked for them, but it’s important to note that it uses chemicals that remove metabolites from the hair shaft, and they may irritate not only your scalp, but your eyes too. People with sensitive scalp or are prone to irritations caused by certain chemicals are therefore at risk of scalp/eye irritation.

According to anecdotal stories, this method can be used a few times before the day of the test, and once on the same day of the test. As this method uses a lot of chemicals, it’s advised to not repeat the process too many times because both the hair and scalp may suffer.

Things Needed:

  • Disposable gloves to protect your hands from drying out;
  • Goggles to protect your eyes (not necessary, but recommended);
  • Shower cap;
  • White vinegar;
  • Old Style Aloe Toxin Rid Shampoo – users claim that the original formula is more effective because it contains propylene glycol which reportedly is the ingredient that helps with the removal of metabolites. The other version (called Nexxus Aloe Rid) is not recommended because the formula is different and it supposedly doesn’t work;
  • Zydot Ultra Clean shampoo – currently, the most reputable among detox shampoos and clinically tested, used to get rid of not only THC but any accumulated substances in the hair shaft, like medication deposits;
  • Clean & Clear Deep Cleaning Astringent or Clean & Clear face wash, both with 2% salicylic acid or Neutrogena T/Sal, a therapeutic shampoo with 3% salicylic acid;
  • Tide liquid detergent.

The process:

While doing this, clean exposed skin areas at all times and try not to let any chemicals seep into your eyes, especially if you’re not using goggles.

  1. First, rinse your hair with warm water and get it thoroughly wet so the hair shaft can open;
  2. Next, put the vinegar on your hair and make sure you get it from roots to tips;
  3. With the vinegar still in your hair, work in the Clean % Clear or Neutrogena in your hair, also from roots to tips;
  4. Put your hair in the shower cap and leave the mix on for 30 minutes, and then rinse;
  5. After rinsing, shampoo twice with the Aloe Toxin Rid;
  6. Then, put on the goggles if using any, and wash your hair with a small amount of liquid Tide detergent, then rinse;
  7. Finally, shampoo twice with the Zydot Ultra Clean. This may take a while as the pack contains a shampoo, a purifier, and a conditioner, all of which you should leave on for a few minutes to work. One pack is enough for two uses.

The Jerry G Method

Jerry G is a real person who developed this method. He claimed that bleaching and dying the hair can considerably reduce the drug metabolites in the hair because bleach opens up the hair cuticles allowing the metabolites to “escape” more easily. 

Please note that this method involves bleaching and dying your hair twice, which can considerably damage your hair and disqualify you from the test because your head hair would be unusable. In this case, they may ask for a sample of body hair (eg. armpit hair).

Things Needed:

  • Peroxide bleach;
  • Hair dye with ammonia, preferably close to your natural color;
  • Old Style Aloe Toxin Rid Shampoo;
  • Zydot Ultra Clean Shampoo;
  • Baking soda.

The process:

As we said, this method involves bleaching and dying your hair twice in the span of at least 10 days. 

  1. First, you’ll have to bleach and dye your hair once and then use the Aloe Toxin Rid Shampoo to wash it;
  2. Then, wait 10 days and bleach and dye it again, and wash it with the Aloe Toxin Rid shampoo again. The second bleach-and-dye session should be done as close to the day of the test as possible;
  3. Next, on the day of the test, you should make a thick baking soda and water paste and massage it into your hair. Leave it on for 15 minutes and wash with the Aloe Toxin Rid shampoo once again; 
  4. The final step of this method is to wash your hair again with the Zydot Ultra Clean shampoo.

Bottom Line – Detoxing for an Extended Period of Time Is the Safest Way to Get THC Out of Your Hair

Being surprised with a hair follicle drug test at work isn’t music to anyone’s ears, so naturally, you would want to avoid getting positive test results. However, it’s not always so simple. The way THC metabolites deposit in your hair makes it nearly impossible to cheat, and not to mention the legal repercussions you might face (which is why we don’t recommend it).

Therefore, if you can afford to do a natural detoxing, do so. That way, you wouldn’t have to risk facing the law or damaging your hair and scalp with harsh chemicals by going through so much trouble that doesn’t guarantee any success.


The information presented on this page is provided as a public service to aid in education and is derived from sources believed to be reliable. Readers are responsible for making their own assessment of the topics discussed here. In no event shall Leaf Nation be held reliable for any injury, loss or damage that could happen if using or abusing drugs.