Table of ContentsView AllTable of Contents"How It Works"“Understanding the Results"“Accuracy"“Cost"“Hair vs. Urine Tests”
Table of ContentsView All
View All
Table of Contents
“How It Works”
“Understanding the Results”
“Accuracy”
“Cost”
“Hair vs. Urine Tests”
A hair follicle drug test is one way to screen for recreational drug use orprescription drug abuse. A section of hair, about 200 strands, is sent to a lab for testing.
One of the benefits of follicle drug tests is that they can show whether someone used or abused drugs as far back as three months before the test.
The test can pick up drugs or drug metabolites inside the hair shaft that have been deposited through the bloodstream. Like urine tests, the drugs that can be detected will vary depending on the chosen panel.
A standard five-panel test looks for:
Read on for more information about hair follicle drug testing, how it’s done, and how accurate it is.
SandraMatic/ Getty Images
Why Is a Hair Follicle Drug Test Necessary?
Drug tests are used to show drug use or misuse. Follicle drug tests can be used in:
How a Hair Follicle Drug Test Works
In a laboratory, a procedure called enzyme-linked immunosorbent assay (ELISA) is performed on the hair sample. The metabolites of a drug react to the test to show a positive, negative, or invalid response.
If the result is positive, a second test called gas chromatography–mass spectrometry (CG-MS) is performed to confirm the result. The CG-MS is a different method of testing for substances and can confirm a positive result from the ELISA test.
To do a hair follicle drug test, a hair sample is taken from the person’s head, close to the scalp. The sample must be 1.5 inches long and about as thick as a pencil, which is about 200 individual strands of hair.It is then sent to a lab for analysis.
The test can detect metabolites of drugs, which are substances made from the breakdown of drugs. It can detect drugs used within the past 90 days.
Home Hair Tests
At-home hair drug tests are available in stores and without a prescription. They involve collecting hair and then sending it to a lab for analysis.
How to Use a Home Hair Test
Using a home hair test is pretty straightforward. First, read the instruction manual so you know what to do. Take the hair sample necessary based on the directions and wrap it in the foil provided.
Is a Home Hair Follicle Test Accurate?
Because home tests are sent to a lab, they’re comparable to regular hair follicle drug tests. Neither type of test is 100% accurate, even though they go through a two-step process.
Understanding Hair Follicle Test Results
The results of the test will be reported as positive, negative, or inconclusive. Here’s what those terms mean.
Negative
A negative result means no drugs or metabolites were found in the sample. It doesn’t mean the person hasn’t used any drugs, however.
The person could have used a drug very recently, before it showed up in the hair. Or, they might not have used enough of the drug to be detected. They could also have used other drugs for which the test didn’t screen.
Positive
A positive result means the drug or metabolite was found in the hair sample. All laboratories have no standard positive cutoff values, which may vary among labs.
Certain foods and medications can cause false positives. Cold remedies, decongestants, and hay fever medicines can show up as amphetamines and poppy seeds may show up as opiates.
Inconclusive
An inconclusive result may mean the hair sample was contaminated or something went wrong with testing. You might be asked to provide another sample.
How Accurate Is a Hair Follicle Drug Test?
Hair follicle drug tests are very accurate in detecting long-term drug use because of the large window of time they can detect.
However, the test may not be able to detect if someone uses drugs very infrequently or uses drugs shortly before the test. Drug use takes about seven to 10 days to show up in the hair.
The accuracy statistics of hair follicle testing is also different for different substances. For example, studies have shown it to be superior to urine testing in detecting cocaine and opioids, but less reliable in detecting marijuana and alcohol.
Other factors may lead to inaccurate or biased results, including:
Can a Hair Follicle Drug Test Identify Date of Drug Use?No, it cannot identify the specific date of drug use. It can only show whether a substance has been used within the past 90 days.
Can a Hair Follicle Drug Test Identify Date of Drug Use?
No, it cannot identify the specific date of drug use. It can only show whether a substance has been used within the past 90 days.
How Much Does a Hair Follicle Drug Test Cost?
The cost of a hair follicle drug test can vary, depending on the kind of hair follicle test ordered (the number of drugs in a screen can differ), where you go for testing, and who ordered the test.
Your health insurance plan may cover the costs, or your employer may if they are ordering it. If you buy a home test, you pay for all the associated fees.
Many at-home tests will charge an extra fee for the laboratory analysis, adding to the total cost of the test. A 12-drug test from one of the industry leaders in hair follicle drug testing costs about $90, including laboratory fees. Other brands can cost less (though might not test for as many substances).
Hair Follicle Drug Test vs. Urine Drug Test
A urine drug test can only detect drug use for several days, while a hair follicle drug test can pick up on drug use for a longer period of time. Some urine tests provide instant results, but hair tests must be sent to a lab for completion.
Research has shown that urine testing can better pick up cannabis, heroin/opioids, benzodiazepines, and methadone, but hair drug tests are better at picking up cocaine. In one study researchers compared hair follicle drug test results in people who admitted their drug use, so they could verify the test gave a positive result.
In people who did not admit to drug use, urine testing was more effective at picking up cannabis and benzodiazepines, and hair testing was better at detecting cocaine and oxycodone.
What if I Have No Hair?
A body hair sample can be collected if someone has no hair on their head.It should be noted, though, that body hair tests can detect drugs used over a more extended period because the hair grows more slowly.
Summary
While most people may be familiar with urine screening drug tests, hair follicle drug tests are also used, although less widely.
Whereas urine drug tests can detect recent drug use, hair follicle drug tests have a much larger window of detection. This allows persistent drug use to be detected along with more isolated instances of drug use.
9 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Gryczynski J, Schwartz RP, Mitchell SG, O’Grady KE, Ondersma SJ.Hair drug testing results and self-reported drug use among primary care patients with moderate-risk illicit drug use.Drug Alcohol Depend. 2014;141:44-50. doi:10.1016/j.drugalcdep.2014.05.001Usman M, Naseer A, Baig Y, et al.Forensic toxicological analysis of hair: a review.Egypt J Forensic Sci. 9, 17 (2019). doi:10.1186/s41935-019-0119-5Koster RA, Alffenaar JW, Greijdanus B, VanDernagel JE, Uges DR.Fast and highly selective LC-MS/MS screening for THC and 16 other abused drugs and metabolites in human hair to monitor patients for drug abuse.Ther Drug Monit.2014;36(2):234-243. doi:10.1097/FTD.0b013e3182a377e8Palamar JJ, Le A, Guarino H, Mateu-Gelabert P.A comparison of the utility of urine- and hair testing in detecting self-reported drug use among young adult opioid users.Drug Alcohol Depend. 2019;200:161-167. doi:10.1016/j.drugalcdep.2019.04.008Paul R, Williams R, Hodson V, Peake C.Detection of cannabinoids in hair after cosmetic application of hemp oil.Sci Rep. 2019;9:2582. doi:10.1038/s41598-019-39609-0Sharma G, Oden N, VanVeldhuisen PC, Bogenschutz MP.Hair analysis and its concordance with self-report for drug users presenting in emergency department.Drug Alcohol Depend. 2016;167:149-155. doi:10.1016/j.drugalcdep.2016.08.007Substance Abuse and Mental Health Services Administration.Clinical drug testing in primary care.Palamar JJ, Salomone A.On the challenges of hair testing to detect underreported substance use in research settings.The American Journal of Drug and Alcohol Abuse. 2023;49(1):1-4.10.1080/00952990.2023.2166414Palamar JJ, Le A, Guarino H, Mateu-Gelabert P.A comparison of the utility of urine and hair testing in detecting self-reported drug use among young adult opioid users.Drug and Alcohol Dependence.2019;200:161-167. doi:10.1016/j.drugalcdep.2019.04.008
9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Gryczynski J, Schwartz RP, Mitchell SG, O’Grady KE, Ondersma SJ.Hair drug testing results and self-reported drug use among primary care patients with moderate-risk illicit drug use.Drug Alcohol Depend. 2014;141:44-50. doi:10.1016/j.drugalcdep.2014.05.001Usman M, Naseer A, Baig Y, et al.Forensic toxicological analysis of hair: a review.Egypt J Forensic Sci. 9, 17 (2019). doi:10.1186/s41935-019-0119-5Koster RA, Alffenaar JW, Greijdanus B, VanDernagel JE, Uges DR.Fast and highly selective LC-MS/MS screening for THC and 16 other abused drugs and metabolites in human hair to monitor patients for drug abuse.Ther Drug Monit.2014;36(2):234-243. doi:10.1097/FTD.0b013e3182a377e8Palamar JJ, Le A, Guarino H, Mateu-Gelabert P.A comparison of the utility of urine- and hair testing in detecting self-reported drug use among young adult opioid users.Drug Alcohol Depend. 2019;200:161-167. doi:10.1016/j.drugalcdep.2019.04.008Paul R, Williams R, Hodson V, Peake C.Detection of cannabinoids in hair after cosmetic application of hemp oil.Sci Rep. 2019;9:2582. doi:10.1038/s41598-019-39609-0Sharma G, Oden N, VanVeldhuisen PC, Bogenschutz MP.Hair analysis and its concordance with self-report for drug users presenting in emergency department.Drug Alcohol Depend. 2016;167:149-155. doi:10.1016/j.drugalcdep.2016.08.007Substance Abuse and Mental Health Services Administration.Clinical drug testing in primary care.Palamar JJ, Salomone A.On the challenges of hair testing to detect underreported substance use in research settings.The American Journal of Drug and Alcohol Abuse. 2023;49(1):1-4.10.1080/00952990.2023.2166414Palamar JJ, Le A, Guarino H, Mateu-Gelabert P.A comparison of the utility of urine and hair testing in detecting self-reported drug use among young adult opioid users.Drug and Alcohol Dependence.2019;200:161-167. doi:10.1016/j.drugalcdep.2019.04.008
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Gryczynski J, Schwartz RP, Mitchell SG, O’Grady KE, Ondersma SJ.Hair drug testing results and self-reported drug use among primary care patients with moderate-risk illicit drug use.Drug Alcohol Depend. 2014;141:44-50. doi:10.1016/j.drugalcdep.2014.05.001Usman M, Naseer A, Baig Y, et al.Forensic toxicological analysis of hair: a review.Egypt J Forensic Sci. 9, 17 (2019). doi:10.1186/s41935-019-0119-5Koster RA, Alffenaar JW, Greijdanus B, VanDernagel JE, Uges DR.Fast and highly selective LC-MS/MS screening for THC and 16 other abused drugs and metabolites in human hair to monitor patients for drug abuse.Ther Drug Monit.2014;36(2):234-243. doi:10.1097/FTD.0b013e3182a377e8Palamar JJ, Le A, Guarino H, Mateu-Gelabert P.A comparison of the utility of urine- and hair testing in detecting self-reported drug use among young adult opioid users.Drug Alcohol Depend. 2019;200:161-167. doi:10.1016/j.drugalcdep.2019.04.008Paul R, Williams R, Hodson V, Peake C.Detection of cannabinoids in hair after cosmetic application of hemp oil.Sci Rep. 2019;9:2582. doi:10.1038/s41598-019-39609-0Sharma G, Oden N, VanVeldhuisen PC, Bogenschutz MP.Hair analysis and its concordance with self-report for drug users presenting in emergency department.Drug Alcohol Depend. 2016;167:149-155. doi:10.1016/j.drugalcdep.2016.08.007Substance Abuse and Mental Health Services Administration.Clinical drug testing in primary care.Palamar JJ, Salomone A.On the challenges of hair testing to detect underreported substance use in research settings.The American Journal of Drug and Alcohol Abuse. 2023;49(1):1-4.10.1080/00952990.2023.2166414Palamar JJ, Le A, Guarino H, Mateu-Gelabert P.A comparison of the utility of urine and hair testing in detecting self-reported drug use among young adult opioid users.Drug and Alcohol Dependence.2019;200:161-167. doi:10.1016/j.drugalcdep.2019.04.008
Gryczynski J, Schwartz RP, Mitchell SG, O’Grady KE, Ondersma SJ.Hair drug testing results and self-reported drug use among primary care patients with moderate-risk illicit drug use.Drug Alcohol Depend. 2014;141:44-50. doi:10.1016/j.drugalcdep.2014.05.001
Usman M, Naseer A, Baig Y, et al.Forensic toxicological analysis of hair: a review.Egypt J Forensic Sci. 9, 17 (2019). doi:10.1186/s41935-019-0119-5
Koster RA, Alffenaar JW, Greijdanus B, VanDernagel JE, Uges DR.Fast and highly selective LC-MS/MS screening for THC and 16 other abused drugs and metabolites in human hair to monitor patients for drug abuse.Ther Drug Monit.2014;36(2):234-243. doi:10.1097/FTD.0b013e3182a377e8
Palamar JJ, Le A, Guarino H, Mateu-Gelabert P.A comparison of the utility of urine- and hair testing in detecting self-reported drug use among young adult opioid users.Drug Alcohol Depend. 2019;200:161-167. doi:10.1016/j.drugalcdep.2019.04.008
Paul R, Williams R, Hodson V, Peake C.Detection of cannabinoids in hair after cosmetic application of hemp oil.Sci Rep. 2019;9:2582. doi:10.1038/s41598-019-39609-0
Sharma G, Oden N, VanVeldhuisen PC, Bogenschutz MP.Hair analysis and its concordance with self-report for drug users presenting in emergency department.Drug Alcohol Depend. 2016;167:149-155. doi:10.1016/j.drugalcdep.2016.08.007
Substance Abuse and Mental Health Services Administration.Clinical drug testing in primary care.
Palamar JJ, Salomone A.On the challenges of hair testing to detect underreported substance use in research settings.The American Journal of Drug and Alcohol Abuse. 2023;49(1):1-4.10.1080/00952990.2023.2166414
Palamar JJ, Le A, Guarino H, Mateu-Gelabert P.A comparison of the utility of urine and hair testing in detecting self-reported drug use among young adult opioid users.Drug and Alcohol Dependence.2019;200:161-167. doi:10.1016/j.drugalcdep.2019.04.008
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