- A hair follicle drug test can detect the presence of illicit or prescription drugs in a person's system by analyzing a small sample of hair. This test can identify drug use within the last 90 days and is commonly used by employers, courts, and addiction treatment centers.
- The drugs enter the hair follicles through the bloodstream, where they remain for up to 90 days or until the hair is removed. The test can detect a variety of drugs, including marijuana, cocaine, opioids, amphetamines, methamphetamine, PCP, and ecstasy.
- Despite its effectiveness, hair follicle drug tests have limitations. They may not detect recent drug use due to the time it takes for hair to grow, and they can produce false positives from environmental exposure to certain drugs. Furthermore, the test cannot determine the frequency of drug use.
- A common misconception about hair drug tests is that they require the actual hair follicle, which would involve pulling hair from the scalp by its root. In reality, only a small hair sample is needed, and this can be taken from anywhere on the body.
- Attempting to evade a hair drug test by shaving all body hair can lead to consequences such as employment denial. The test doesn't reveal how often drugs were used, which can be problematic for those who have stopped using drugs but still test positive due to previous use.
A hair follicle drug test can detect whether a person has illicit or prescription drugs in their system. If you’re about to have a hair drug test or want a loved one to take this test, it may help to know how long drugs stay in hair follicles, how effective the tests are, and where you can get a test from a quality provider in your area.
What Is a Hair Drug test?
A hair drug test is a type of drug test that uses several of your hair follicles to test for the presence of drugs in your body. During this test, a lab technician cuts a small number of hairs from your head using a pair of scissors. Your hair sample is then sent to a lab where technicians screen it for the presence of drug use within the last 90 days according to the National Institutes of Health (NIH)
According to the NIH, a hair drug test can detect the presence of:
According to the Society for Human Resource Management, hair drug tests are used by approximately 7% of employers that screen employees for drug use. This type of drug test may be used by employers, courts, addiction treatment centers, and individuals who want themselves or a loved one tested for drug use, reports the NIH.
How does the drug travel into the hair?
The NIH reports that any drug or substance you use enters your bloodstream, which transports the drug and its metabolites all throughout the body. According to Duke University, your hair follicles are surrounded by a series of small, thin blood vessels that provide the follicles with oxygen and nutrients that help them grow and thrive. The drugs you use can enter and stay in your hair follicles for 90 days or until the hair is removed.
How far back does a hair follicle test detect drugs?
A hair follicle test can detect whether you have used certain types of drugs at any point during the last 90 days, according to a study in Drug and Alcohol Dependence. However, this drug test does not reveal how often you used those drugs during that time frame.
Hair follicle drug tests are not quite as foolproof as we thought
Hair takes time to grow, and hair drug tests may not show whether a person has used drugs during the past few days. Many times, it can take between five and seven days for substances to be detectable on a hair follicle drug test.
Additionally, according to the University of Richmond, hair follicle tests may come back positive for people who may have been exposed to certain drugs without actually using them. For example, cocaine can bind to a substance in hair called melanin, which controls the pigment of your hair. If you had entered a room where people were snorting cocaine, it’s possible some cocaine may have landed in your hair and caused you to test positive for it.
Lastly, hair follicle tests cannot reveal how often you do drugs. If you were using marijuana nearly three months ago and stopped because you decided to seek treatment at a drug rehab center, that drug will still show up in your system despite not using it for almost 90 days, according to a study in Drug and Alcohol Dependence. This can be problematic for those who have decided to become healthy. Some people cannot secure employment due to previous drug use and a positive hair test for marijuana.
Misconception of hair drug tests
A common misconception of a hair drug test is that the test requires a sample of the actual hair follicle. This would require the hair to be pulled from the scalp by its root. However, this is normally only required for genetic and DNA testing, according to NIH .
Some people think they can avoid testing positive for drugs with a hair test if they shave all the hair from their head. However, hair samples can be taken from nearly anywhere on the body, and not just on the head. Those who shave all their body hairs in an attempt to escape a positive result may face consequences such as being denied employment, according to Medline Plus.
Frequently asked questions
How Much Does a Hair Follicle Test Cost?
According to data from Medline Plus, hair follicle drug test can cost anywhere between $15 and $125, depending on factors including the test manufacturer, fees set by the testing provider, and your geographical location. The cost may be covered by your employer if it is required for employment. In other cases, your health insurance provider may pay for it if your doctor deems this test medically necessary based on your health situation.
Does Dying Your Hair Affect Drug Tests?
Hair products including dyes, hairsprays, and shampoos will not affect the results of a hair drug test, reports the NIH. Drugs enter your hair from the bloodstream, therefore, bleaching it or dying it a different color will not affect the outcome.
Does a Hair Follicle Test Show the Frequency of Drug Use?
According to Medline Plus, A hair test can only show whether a person has used certain drugs within the last 90 days. It cannot reveal the frequency of drug use.
Which Is Better: A Hair Test or Urine Test?
Hair drug tests and urine drug tests each come with their own set of pros and cons. One of the primary benefits of a hair drug test is its relatively long detection window. A hair test can determine whether a person has used drugs within the last 90 days, while a urine test can only detect drug use during the last three days, based on data published in Drug and Alcohol Dependence.
Though a hair drug test may be better at determining whether a person has used drugs in the last 90 days, it doesn’t necessarily reveal the frequency of drug use. These tests also tend to be higher in cost than urine tests. According to Drug and Alcohol Dependence, some people are resistant to submit to hair drug testing due to concerns it may affect their physical appearance after a large number of hairs are removed for the test.
A urine test is usually less invasive than a hair test, as it catches a small sample of urine that needs to be expelled from the body regardless of testing. In comparison, a hair test leads to a small amount of hair loss, as it involves cutting a sample of hairs from your scalp.
Choosing between a hair follicle test and a urine drug test comes down to a matter of personal preference, or to that of the employer, court, or organization requiring the drug test.
What Can Cause a False Positive Hair Follicle Test?
Hair follicle testing follows a specific set of standards that help protect its accuracy and prevent false-positive results, according to Medline Plus.
In previous years, foods like poppy seeds and hemp seeds often produced false-positive results, but today, labs conduct two separate tests to guard against false positives. According to data from Medline Plus, the first test, called the ELISA test, produces a negative or positive result within 24 hours. The second test, called the GC/MS test, has the ability to confirm whether a positive result is truly positive, as it guards against substances that may cause false positives.
The only time a hair follicle test will produce a false positive is when you are using a prescription medication that can be detected by the hair test, such as an opioid medication, according to Medline Plus. If this occurs, you may be asked to provide proof of a valid prescription for that particular substance.
How Can I Find a Hair Follicle Drug Test Near Me?
The easiest way to find a hair drug test provider near you is to visit Solv. Solv can provide you with a list of highly-rated lab testing providers in your area, as well as the opportunity to book a same-day appointment at a walk-in clinic. Visit Solv today to benefit from convenient, hassle-free healthcare for you and your entire family.
Solv has strict sourcing guidelines and relies on peer-reviewed studies, academic research institutions, and medical associations. We avoid using tertiary references.
- Hair Drug Testing Results and Self-reported Drug Use among Primary Care Patients with Moderate-risk Illicit Drug Use (August 1, 2014)
- Hair, Saliva or Urine—Which Is Best for Drug-Testing Job Candidates? (February 15, 2018)
- Drug Testing (July 31, 2020)
- How Do Drugs Get Into a Person’s Hair? (April 2, 2018)
- How do drugs get out of the blood and into hair follicles