Hair Follicle Drug Test: Definition, Purpose, and How It Works
16 August, 2023
A hair follicle drug test checks for the use of illicit substances through the hair strands. The process involves getting a specimen from the hair shaft or hair from other body parts. Hair testing is one of the most reliable and accurate ways of detecting substance abuse. This method helps healthcare providers or employers to evaluate a person’s past usage or consumption patterns. Moreover, it uses a technique called Gas Chromatography-Mass Spectrometry (GC-MS) to detect drug metabolites.
A hair test is valuable in drug or abstinence monitoring to determine a person’s long-term behaviour. It is also non-invasive and has an easy sample collection procedure. However, it is less common than urine or oral fluid testing because it is time consuming and more complicated to analyse. Nevertheless, it is useful in identifying substance abuse. In this article, we will delve into what hair drug test is all about, including its purpose and how it works.
What is a Hair Follicle Drug Test?
A hair follicle drug test is a detection method that looks for traces of drug metabolites in hair specimens. When a person ingests drugs or alcohol, the body processes them and produces a byproduct called metabolites. Trace amounts of metabolites enter the hair follicles and remain within the shaft as it grows.
Due to the rate of hair growth, the test can determine if a person has consumed drugs or alcohol within the past 90 days. It can also detect periods of abstinence. However, unlike a urine or blood test, it cannot measure the drug concentration levels or the amount of consumption. Additionally, hair test kits are available to enable individuals or companies to provide a hair sample and send it to a laboratory for analysis.
The process involves cutting 1.5 inches of hair of approximately 100 to 200 strands. This amount is sufficient to cover the past 90 days. In addition, a collector would prefer the top of the head for the sample as the growth rate is more consistent than in other areas. If head hair is not available, body hair can be used.
What Can Be Detected
- Ethanol and ethyl glucuronide (EtG): a byproduct of ethanol formed in the liver. Its presence indicates the consumption of alcohol within the specified period.
- Cocaine: codeine, morphine, oxycodone, and hydrocodone are detectable in a hair test. These drugs are often abused for recreational purposes or to manage pain.
- Amphetamine: includes methamphetamine and MDMA (ecstasy). These drugs have the potential to cause addiction.
- Marijuana (THC): the psychoactive compound from the cannabis plant. It is commonly abused for recreational purposes.
- Opiates: powerful pain-relieving drugs. It has a high risk of developing addiction, and when taken outside prescription often leads to overdose.
Why Conduct Hair Follicle Drug Test?
A hair follicle drug test is beneficial for several reasons. The main purpose of the test is to detect evidence of past drug use or misuse. It is valuable for screening and confirmation, especially for employment and legal cases. Because it can trace drugs for several months, it is ideal in sobriety monitoring programs such as treatment centres and workplaces.
Hair follicle testing helps screen applicants and employees for illicit substances. It is useful in assessing if a person uses drugs habitually. Thus, it aids employers in hiring the most suitable candidate, especially for safety-sensitive positions. Furthermore, companies may use it for random monitoring, serving as a deterrent for drug abuse.
Another purpose of the test is to provide evidence in legal proceedings. It can be used to prove drug use or non-use and support claims made in court. Hair samples may be collected during criminal investigations in drug-facilitated crimes and child protection cases. It is helpful in determining long-term use where a person is supposed to abstain.
A hair test is a reliable and accurate method of screening for drugs and alcohol. It is a non-invasive and painless method for sample collection. The samples are easy to obtain and are stable for long-term storage. External factors such as temperature and humidity do not affect the results.
Hair testing eliminates the possibility of tampering, adulteration and dilution, which are common in urine tests. Its window of detection is also longer than that of other methods. Therefore, a person cannot easily manipulate the results by abstaining from substance use for several days or weeks.
How Does a Hair Follicle Drug Test Work?
When a person ingests drugs, it absorbs into the bloodstream and enters several organs. Small portions deposit in the hair follicle. As a result, metabolites or trace amounts of the parent drug remain in the hair as it grows. A hair follicle drug test can detect substances one week after the initial exposure, depending on the hair growth.
A collector takes strands of hair from the back of the head, close to the scalp, to ensure it represents the most recent consumption. The sample is then sent to a laboratory for analysis to screen for substance use in the past 90 days. It can detect cocaine, phencyclidine (PCP), amphetamines, opioids, benzodiazepines, and marijuana. Environmental exposure, like second-hand marijuana smoke, may also integrate into the hair strands.
In the lab, technicians wash the specimen to remove external contaminants like shampoos and smoke before testing. The initial screening uses the ELISA method to release the drugs and their metabolites. If the result is positive, it undergoes a follow-up test. Laboratories use GC-MS to detect concentrations of drugs in hair. Lastly, the results may be available after 24 hours.
Hair testing is accurate in detecting past drug use. It is difficult to tamper, making it one of the most reliable methods. Nevertheless, not all drug tests are 100% accurate. While hair products may not affect the results, other factors like sweat and smoke may interfere. Thus, it is vital to follow strict procedures in sample collection and analysis to ensure its accuracy.
As mentioned earlier, the test undergoes a two-step process to avoid false positives. After screening, the samples undergo a confirmation test. Thus, ensures the results are valid before reporting it to an employer, medical provider, or court.
A hair follicle drug test is a reliable, non-invasive method for detecting substance abuse. It can trace illicit drugs and alcohol for the past 90 days. It helps determine a person’s history or consumption pattern due to its long detection period. Moreover, it is valuable in rehabilitation centres for monitoring sobriety or abstinence. A hair drug test is also applicable in workplaces for screening applicants and employees, as well as providing evidence for legal proceedings.
The test is generally accurate as hair specimen is difficult to tamper or adulterate. The collection process is simple and painless. Then, it undergoes advanced laboratory procedures to identify the specific drug substance. If the initial screening is positive, a secondary test through GC-MS ensures the accuracy and validity of the final result. Overall, it is one of the preferred methods in healthcare and legal settings for identifying illegal drug use and the misuse of prescription medications and alcohol.