The detection of weed in hair is an interesting topic, especially in the context of drug testing. Unlike other testing methods that may detect weed use over a short period, hair follicle drug detection times are longer. This is because THC, the active compound in weed, is deposited into our hair follicles. As our hair grows, traces of it remain embedded in the hair strands. Understanding how long marijuana stays in the hair is crucial, if you are concerned about drug testing, as it may impact personal, legal, and employment schemes. In this article, we will discuss how long weed stays in hair, how hair drug tests work, what substances they can detect, which employers use hair drug tests and, of course, some tips to beat a hair drug test.
How Long Does Marijuana Stay in Your Hair Follicles?
THC or Tetrahydrocannabinol is the primary psychoactive compound found in marijuana. It is responsible for the ‘high’ that users experience when they consume marijuana. Because THC is fat soluble, it is stored in our body’s fat cells and may linger in our system for extended periods. That explains why THC is detected in our bodies long after the effects have worn off.
How long weed stays in your system depends on several factors, including the body metabolism, fat percentage, potency of drugs, frequency of use, and the testing method. Here is a simple comparison.
| Test | Urine | Blood | Saliva | Hair |
| Occasional Use | 3-7 days | 1 -2 days | 1-3 days | Up to 90 days |
| Regular Use | 1-3 weeks | Up to 7 days | Up to 7 days | Up to 90 days |
| Heavy Use | 30 days or more | 7 days | Up to 30 days | 90 days or more |
Now you understand that the answer to the question how long does THC stay in system is different in each analysis or the testing method.
Why THC Stays Longer in Hair
You would have also noted that the longest detection window is seen in hair tests. Ever wondered why?
THC stays longer in our hair, primarily because of how our hair grows and the way THC metabolites get deposited and stored in our hair follicles.
Once we consume weed, THC enters our blood stream, eventually reaches our hair follicles, and deposits into the growing hair shaft. As our hair grows slowly (about half an inch per month), doesn’t regularly shed or renew itself like other biological cells and tissues, the THC metabolites get “trapped” in our hair as it grows. Therefore, the removal of these metabolites from the hair is slow.
Also, our hair is more resistant to external changes when compared with other fluids like urine, blood or saliva. This resistance is an additional feature which makes hair testing capable of detecting weed use over a much longer period – up to 90 days or more. The detection window can be extended beyond 3 months, if a longer hair sample is tested. However, most labs stick to the 1.5 inch standard, unless otherwise requested.
It is important to note, that it will take about 7 days for the consumed drug to show up in the hair shaft. That is a limitation of hair drug tests. It takes time for metabolites like THC to grow out into our hair. Therefore, hair drug tests typically don’t detect very recent drug use.
Hope the above explanation answers the frequently asked question How long does delta 8 stay in your system, which is up to 90 days. Delta-8-tetrahydrocannabinol is the scientific name for the naturally occurring psychoactive metabolite found in weed, also known as THC. Hair drug tests are not only reliable in assessing long term drug use, but they are also resistant to tampering.
What Substance Can a Hair Drug Test Detect?
Commonly detected drugs include;
- Marijuana (pot /weed)
- Cocaine
- Opiates (heroin, codeine)
- Amphetamines (methamphetamine, ecstasy)
- Phencyclidine (PCP)
Other uncommon substances include; fentanyl, tramadol, buprenorphine, benzodiazepines, barbiturates, ketamine, zolpidem
How Does a Hair Drug Test Work?
Hair drug test is one of the newest types of drug testing available. As it is noninvasive and samples are easy to obtain, it is becoming popular among employers as well as court ordered probation tests. Hair drug test is done by analysing a small sample of your hair to detect drug use over an extended period of time, typically up to 90 days.
Sample Collection
Although it is commonly called hair follicle drug test, actually hair follicles are not tested. Hair strand is cut very close to the scalp for the hair drug test. If scalp hair is not long enough (at least 1.5 inches) or unavailable, body hair can be obtained from your arm, leg, beard area or underarm.
Laboratory Analysis
The hair sample needs to be washed in a laboratory, to remove external contaminants. Then it will be dissolved using chemicals, to release the drug metabolites such as THC trapped inside the hair shaft.
Testing Process
A process called immunoassay screening will be done to detect drug metabolites. If it is positive, which means the drug is present in the sample, the quantity of the specific drug will be measured by a more precise test called gas chromatography-mass spectrometry. Therefore a hair drug test can confirm the presence of the drug as well as the quantity of the metabolite in the specific hair sample.
Test results can be obtained within 2-3 days. Hair drug tests are very effective when administered by a properly trained technician.
Although hair drug tests are valued for its long detection window, it may be less effective in people with short, thin hair and may not reflect one time drug use or occasional use, accurately. Also, as hair tests can identify drug use further back in a person’s past, many employers opt for it as a pre-employment screening. These tests can be ordered online or by calling.
There are many types of hair drug testing. For example, 5 panel hair test screens for marijuana, 7 panel, 9 panel, 12 panel etc tests for other substances
Which Employers Use Hair Drug Tests?
Most employers require a safe and healthy workforce and many companies test workers for drug use. According to research, the majority use urine testing over blood, saliva or hair tests. Urinalysis is currently the approved drug testing method for workplaces covered by the federal guidelines. This is convenient as it is easy to collect specimens and can be screened for many illicit drugs.
Hair drug testing is simple and non-invasive and it offers a longer detection window. It is most effective when testing for regular and long term use of weed. On the plus side, hair drug tests can give employers an accurate picture of an applicant’s drug use history and hair tests are difficult to tamper with. The drawbacks are it is more expensive and time consuming than other drug tests.
Hair testing is currently not allowed for DOT (Department of Transportation) testing or federal workplace drug testing. Although DOT has explored the possibility of including hair testing as an alternative method, it has not been officially adopted. Also certain federal positions with exceptionally high safety and security requirements might consider hair testing.
It is a very popular method with non-DOT employers. For example:
- Technology companies – Google, Microsoft, Apple
- Retail and E-Commerce – Amazon, Target, Walmart
- Education institutes – Harvard university, private and public schools
- Financial services – Bank of America, Wells Fargo
- Healthcare providers – Mayo clinic, Cleveland clinic
- Hospitality and food service – Hilton, Starbucks
How Can You Beat a Hair Follicle Drug Test? Dos And Don’ts
Passing a hair follicle drug test is challenging, because of the ability of this test to detect drug use over an extended period (90 days). Although we will outline tips on how to pass a drug test in this article, it is important to understand that none of these methods are guaranteed to work. It can be risky health-wise and if you are caught cheating or tampering with a drug test, you may have to deal with legal and professional consequences.
However, here are some commonly used strategies:
Allow Time
The most reliable and safest way to pass a hair drug test is to stay clean. Refrain from weed use for at least 90 days, allowing hair that contains THC to grow out and cut off. If you have enough time, prior to hair drug test, complete abstinence of 3 months will ensure a negative result.
Use a Detox Shampoo
Detox shampoos claim to penetrate the hair shaft and remove toxins. Although they are safe to use, their effectiveness is widely debated. You don’t need to shave your scalp and entire body hair to cheat. You may also avoid using bleach or other harsh methods which can damage your scalp and hair.
Choose a good-quality shampoo for hair purification. But it is recommended to use detox shampoos at least 15 times before facing a hair drug test. The more drugs you have used, the more often you will need to wash your hair.
Examples of hair follicle drug testing shampoos include:
- Old Style Aloe Toxin Rid Shampoo
- Zydot Ultra Clean
- Nexxus Aloe Rid Shampoo
- High Voltage Folli-Cleanse Detox Shampoo
Hair Treatments – Bleaching and Dying Multiple Times
This may potentially reduce the concentration of THC, but doesn’t guarantee a negative result. Note that the labs are aware of this tactic.
Harsh chemical treatments can damage your hair cuticle, making it more porous and affecting the distribution of drug metabolites. This can lead to inconsistent hair drug test results.
DIY Remedies – Macujo Method
This includes washing your hair multiple times with laundry detergent, vinegar and salicylic acid shampoo. Avoid it as it can damage your scalp and hair, and increase breakage. These methods have no scientific backing.
Also, some harsh treatments may leave chemical residues in your hair, which might interfere with the drug testing process or even lead to false positive results.
Detox Pills
These are marketed as a way to cleanse your body of drug metabolites and toxins to help pass a drug test. However, when it comes to hair drug tests, generally, detox pills are not effective. Detox pills primarily target our body’s detoxification organs like liver and kidney and may be effective for blood and urine tests, but do not affect the THC in hair. Some detox pills may contain strong diuretics and laxatives, which can lead to serious health issues like electrolyte imbalances and dehydration.
Hair Removal – Shave Head and Body Entirely to Avoid Drug Testing
However, this may raise suspicion and you may have to undergo another testing method. Good hydration, nutrition and regular exercise may also not help in passing a hair drug test, although it might clear drug metabolites quicker and improve your overall health.
Conclusion
Understanding how long weed stays in your hair is crucial for any of us undergoing drug testing, whether for personal, employment or legal reasons. A hair drug test can detect THC for up to 90 days, making it one of the most comprehensive methods for assessing long-term drug use. Attempting to cheat can have serious consequences and may damage your reputation. Weigh the benefits and risks prior to attempting these tips. The best way is abstinence. It is better to focus on your long-term health and well-being and lifestyle choices rather than trying to circumvent a drug test.
