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An Overview of How Hair Follicle Drug Testing Works

Hair Follicle Drug Testing

We live in a world where ensuring the safety and reliability of potential employees is paramount. The need for pre-employment drug screening has never been more evident. One method that has proven its testing accuracy is hair follicle drug testing.

In this article, we delve into the intricacies of this testing procedure. We’ll explore why it has become a valuable tool for companies and individuals alike.

Keep reading to learn all you need to know about hair follicle drug testing

Introduction to Hair Follicle Drug Testing

In the pursuit of a drug-free workplace, companies have turned to various methods for screening potential employees. Among these, hair follicle drug testing stands out as a reliable and accurate option.

By examining the hair shaft, this test can provide a detailed history of an individual’s drug use. So, let’s explore how this method works and why it is so effective.

The Science Behind Hair Testing

Hair follicle drug testing involves analyzing the hair shaft to detect the presence of drug metabolites. These are the byproducts that remain in the body after the consumption of drugs.

When a person consumes drugs, the metabolites are circulated through the bloodstream and deposited in the hair shaft. As the hair grows, these metabolites become trapped within the strands.

To conduct the test, a small sample of hair is collected, usually from the crown of the head. This sample is then sent to a laboratory for analysis. The hair is broken down using chemical processes, and the metabolites are extracted and identified.

Advantages of Hair Follicle Drug Testing

There are several reasons why hair follicle drug testing is preferred by many companies and individuals:

Long Detection Window

Hair testing can detect drug use for up to 90 days, depending on the length of the hair sample. This is a significant advantage compared to urine or saliva tests, which have much shorter detection windows.

Testing Accuracy

Hair testing has a high degree of accuracy. Other methods are easier to tamper with. With hair follicle testing, it is difficult to tamper with or adulterate the sample.


Collecting a hair sample is a relatively non-invasive procedure compared to other drug testing methods, such as blood tests. This eliminates difficulties with people who may be squeamish or queasy around blood. 

Applications of Hair Follicle Drug Testing

The accuracy and reliability of hair follicle drug testing make it ideal for various applications, including:

Pre-Employment Drug Screening

Companies looking to maintain a drug-free work environment often incorporate hair testing as part of their hiring process. This ensures that potential employees have not engaged in drug use during the 90 days preceding the test.

Random Drug Testing

Companies may choose to conduct random hair follicle drug tests. This ensures their employees remain drug-free during their employment.

Legal and Forensic Purposes

Hair testing can be used as evidence in legal cases. Examples of cases may be;

  • custody battles
  • DUI cases
  • drug-related offenses

Rehabilitation Monitoring

Treatment centers and rehabilitation facilities may use hair follicle drug testing to monitor their patients’ progress and ensure they remain drug-free during their recovery.

A Hypothetical Example of Hair Follicle Drug Testing

Imagine a company that is in the process of hiring new employees. They have a strict drug-free workplace policy and want to ensure that their potential employees adhere to this standard. They decide to use hair follicle drug testing as part of their pre-employment screening process.

During the interview process, the company informs applicants that they will be required to undergo a hair follicle drug test. After a candidate accepts a job offer, they are scheduled for testing.

A technician collects a hair sample from the crown of the candidate’s head. The sample is then sent to a laboratory for analysis. The laboratory uses advanced chemical processes to break down the hair sample and extract the drug metabolites.

After the analysis, the lab provides the company with a detailed report of the findings. If the report shows no signs of drug use, the candidate proceeds with the hiring process. However, if the report indicates drug use within the last 90 days, the company may rescind the job offer based on their drug-free workplace policy.

By implementing hair follicle drug testing as part of their pre-employment screening process, the company can ensure that they are hiring individuals who adhere to their drug-free standards. This contributes to a safer and more productive work environment.

Limitations and Concerns

Despite the advantages of hair follicle drug testing, there are some limitations and concerns to consider:

Slow Hair Growth

If a person’s hair grows slowly or has been cut very short, it may be challenging to obtain an adequate sample for testing. In such cases, alternative drug testing methods may be necessary.

External Contamination

In some instances, hair can be contaminated by external sources, such as secondhand smoke or drug residue in the environment. However, modern testing methods can differentiate between external contamination and actual drug use.

Ethnic Bias

Studies have shown that certain hair types, particularly those with thicker and darker strands, can retain drug metabolites more effectively. This may lead to a higher likelihood of a positive test result for individuals with such hair types. Laboratories are aware of this issue and use specific procedures to minimize the potential for bias.


Hair follicle drug testing can be more expensive than other drug testing methods, such as urine or saliva tests. However, the increased accuracy and longer detection window often justify the additional expense.

The Value of Hair Follicle Drug Testing

In today’s fast-paced world, ensuring the safety and reliability of potential employees is of utmost importance. Hair follicle drug testing has proven itself as a valuable tool in this endeavor, offering a high degree of accuracy and a longer detection window than other methods.

By understanding how this testing procedure works and its applications, companies and individuals can make informed decisions when it comes to drug screening and maintaining a drug-free environment.

Get in touch today if you want to learn more, or if you’re considering implementing drug testing in the workplace.

Order a Test

Whether you are an individual looking to get a drug test done today or an employer looking to get a pre-employment drug test done today, ordering a test online is easier than ever! Just submit your order online, receive your test authorization by email, go to your local clinic to be tested, and receive your test results in 24 to 48 hours.

Hours of Operation

Monday 8AM–12PM, 1–4:30PM
Tuesday 8AM–12PM, 1–4:30PM
Wednesday 8AM–12PM, 1–4:30PM
Thursday 8AM–12PM, 1–4:30PM
Friday 8AM–12:30PM, 1–3PM
Saturday Closed
Sunday Closed

Closed Dec. 25, Dec. 26 and Jan. 1

If you have any questions, please do not hesitate to contact our lab.