How Long Does THC Stay in Your Hair?
Although marijuana has become more integrated into popular culture, Testing for illicit substances is still used as pre-employment screening process at many companies.
THC is the primary psychoactive element of weed or cannabis, so Drug tests for cannabis measure THC and its by-products or metabolites.
Generally speaking, Hair follicle drug tests is a common choice for workplace screenings and legal cases.
Understanding how long THC 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, I will discuss how long THC stays in hair, factors influence it, how hair drug tests work, and some possible ways to beat a hair drug test.
How is THC Stored in Hair?
THC reaches the hair follicle through the bloodstream, where it binds to melanin (the pigment in hair).
Once stored in hair shafts, THC remains detectable for up to 90 days—or even longer in body hair.
How Long Does THC Stay in Your Hair?
THC detection timelines depend on metabolism, dosage, and frequency of use. However, in most cases, THC and its metabolites can be detected in hair for up to 90 days.
Typically, hair test is most reliable for daily or near-daily users but is not able to detect light cannabis consumption. Smoking weed or having an edible once or twice may not show up in this test.
THC takes time to build up in your hair follicles. If you use weed today, it won’t show in a hair test until seven to 10 days later.
Additionally, Exposure to second-hand marijuana smoke or physical contact with someone who has handled cannabis could potentially lead to a false positive in hair test.
Factors that Affect How Long Marijuana Stays in Your Hair?
There are 5 main different factors can impact how long marijuana stays in your hair.
1. Frequency of Use
Someone who has been using marijuana regularly is likely to have a buildup of THC in their system, meaning it will take longer to leave the body.
Occasional users will typically clear THC from their body or hair quicker than habitual users.
2. Concentration Levels of THC
Marijuana product can have varying levels of THC. If marijuana oil or concentrates with a higher THC potency is used, the chemical traces will remain in the body for longer periods of time.
3. Metabolism
Those people who have faster metabolisms, reducing the time weed is detectable in their system.
Conversely, those with slower metabolisms may have detectable traces of cannabis for longer.
4. Fat Percentage
THC is stored in the body’s fatty tissue. Those with less fat in their body will clear their system of THC faster than those who have more fat.
5. Hair Health and Color
Healthy hair is better at retaining metabolites than unhealthy or damaged hair. This is because THC is stored in the hair’s cortex and can be detected until the hair is shed or cut.
Individuals with lighter hair colors will typically see a shorter detection window than those with darker hair. This is because melanin, the pigment found in darker hair colors, helps act as a binding agent for THC.
Why THC Stays Longer in Hair?
THC stays longer in our hair rather than urine, blood, and saliva, 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. It can’t be washed off because it’s not on the surface.
As our hair grows slowly (about 1/4 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.
How Does a Hair Follicle Test Work for THC?
You will be asked to provide a hair sample, and the 1.5 inches nearest to the scalp will be tested.
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.
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.
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.
How to Pass a Hair Follicle Drug Test?
The only way to ensure you pass a hair follicle drug test for cannabis use is to stop using cannabis at least 90 days before the test which will ensure that all THC is detoxed from your system.
In addition, there are many questionable tips and tricks for how to pass a drug test for marijuana:
Repeatedly dying your hair: THC is stored with melanin in the hair. In order to beat the test, we have to destroy the melanin within the hair.
The process is bleach your hair twice and Dye your hair back to a normal color.
However, This process will damage the hair very much, and has the possibility to burn your scalp.
Exercise: THC is stored in fat and so a good way to decrease the amount of THC in the body is to sweat it out. Try exercise or go to a sauna.
Note that exercise before a drug test can actually backfire by releasing THC metabolites from fatty tissue into the blood.
Final Thoughts
Every time you ingest cannabis, THC and its metabolites will end up in your hair.
Hair follicle tests are less commonly used as they can sometimes give false positives. However, Scalp hair can indicate marijuana use for three months.
How long THC stays in your hair depends on several factors, including the body metabolism, fat percentage, potency of drugs, frequency of use, Hair Health and Color, etc.
Understanding these factors and testing procedures can help you make informed decisions about cannabis use and drug testing policies.
The only completely reliable way to pass a THC hair drug test is to stop using marijuana for at least 3 months.
Be cautious to avoid cannabis users prior to a drug test, as the hair follicle test may cann't distinguish between firsthand and secondhand exposure.