--- title: "How long does a hair follicle drug test" description: "Learn how long does a hair follicle drug test detect drugs. Understand detection windows and lab process. Call (877) 731-6362 for testing info." author: "AMH Nationwide" date: "2026-08-28" tags: ["how long does a hair follicle drug test", "how long does a hair follicle drug test | how long does a hair follicle test for drugs | how long does hair follicle drug test"] canonical: "https://amhnationwide.com/how-long-does-a-hair-follicle-drug-test/" last_updated: "2026-08-28" --- # How long does a hair follicle drug test **By AMH Nationwide** | August 28, 2026 Learn how long does a hair follicle drug test detect drugs. Understand detection windows and lab process. Call (877) 731-6362 for testing info. --- How long does a hair follicle drug test detect drugs depends on hair length and substance but typically covers up to 90 days of drug use. This test analyzes hair samples collected at authorized sites and reviewed by certified Medical Review Officers. Call (877) 731-6362 to schedule testing or get more information. [DETECTION WINDOW](https://amhnationwide.com/hair-follicle-drug-test-detection-window/) ## How long does a hair follicle drug test detect drugs? A hair follicle drug test can detect drug use for up to 90 days prior to the test date. This is because drugs and their metabolites are deposited in the hair shaft from the bloodstream as hair grows. Typically, a 1.5-inch hair sample represents approximately three months of drug history. The test is not effective for detecting very recent drug use within the past 5 to 7 days, as hair needs time to grow above the scalp to be sampled. TEST PROCESS ## How is a hair follicle drug test performed? The hair follicle drug test involves collecting a small sample of hair, usually about 100 strands, from the crown of the head or another body area if head hair is unavailable. The sample is then sent to one of five national lab networks: [Quest Diagnostics](https://www.questdiagnostics.com/), [LabCorp](https://www.labcorp.com/), Omega Labs, United States Drug Testing Labs, or ExperTox. AMH Nationwide provides the lab order and directs the requester to a local collection site. There is no online ordering for this test. All non-negative results undergo review by a certified Medical Review Officer as part of standard processing. WHO ORDERS ## Who typically orders hair follicle drug testing? Employers frequently use hair follicle drug tests for [pre-employment](https://amhnationwide.com/pre-employment-hair-testing/) screening or random employee testing due to the extended detection window and resistance to tampering. Courts, [probation](https://amhnationwide.com/hair-follicle-drug-test-probation/) officers, and legal agencies may also require hair follicle tests to monitor drug use over a longer period. Individuals may request hair follicle testing for personal reasons, such as verifying abstinence or for custody cases. SPECIFICS ## How long does a hair follicle test for drugs detect different substances? Hair follicle testing generally detects most common drugs for up to 90 days. Detection windows vary slightly by drug type but are generally consistent due to hair growth rates. | Drug Type | Typical Detection Window | | --- | --- | | Marijuana (THC) | Up to 90 days | | Cocaine | Up to 90 days | | Opiates (Heroin, Morphine) | Up to 90 days | | Amphetamines | Up to 90 days | | Phencyclidine (PCP) | Up to 90 days | ## Schedule Your Hair Follicle Drug Test Today Contact AMH Nationwide for lab testing through one of our five national lab networks. Call (877) 731-6362 to arrange testing or to speak with a testing coordinator. [Call (877) 731-6362](tel:+18777316362)[Contact Us](https://amhnationwide.com/contact-us/) LIMITATIONS ## Can hair follicle drug tests detect one-time or passive drug exposure? Hair follicle tests detect drug use reflected in incorporated metabolites over weeks to months. One-time or very recent drug use may not be detected if hair has not yet grown out. Passive exposure to drugs is unlikely to produce a positive result because the test detects metabolites inside the hair shaft, not external contamination. Labs follow strict washing protocols to remove external substances. COMPLIANCE ## Are hair follicle drug tests compliant with DOT regulations? Hair follicle drug tests are not used for Department of Transportation (DOT) safety-sensitive testing. DOT-regulated testing requires federally certified [urine](https://amhnationwide.com/urine-drug-testing/) protocols under [49 CFR Part 40](https://www.transportation.gov/odapc/part40). Hair testing is reserved for non-DOT roles or as additional testing but must follow strict chain-of-custody and lab certification standards. AMH Reviewed & Maintained By AMH Nationwide Customer Service AMH Nationwide is BBB A+ accredited and routes every order through Quest Diagnostics, LabCorp, Omega Labs, United States Drug Testing Labs, or ExperTox, all of which use multiple lab certification agencies and standards such as [SAMHSA](https://www.samhsa.gov/workplace/drug-testing)-aligned laboratory protocols, the ANSI National Accreditation Board for forensic testing and calibration, the College of American Pathologists (CAP), and Clinical Laboratory Improvement Amendments (CLIA). Every non-negative screen is reviewed by a certified Medical Review Officer as part of standard processing before a result is released, and chain-of-custody documentation is maintained on every collection. This page does not constitute medical or legal advice. **Last updated:** July 2026 You May Also Need [Nail Drug TestingNo head or body hair available? A 5-panel fingernail test covers a similar look-back window.Learn more →](https://amhnationwide.com/5-panel-fingernail-drug-test/)[ChildGuard: Environmental ExposureConcerned about a child or loved one? ChildGuard screens for exposure to drugs in their environment.Learn more →](https://amhnationwide.com/5-panel-hair-drug-test-environmental-exposure-childguard/)[Shorten the Detection WindowShortened options like 30 and 60 day hair panels are also available, useful when a urine test’s 1-3 day window is too short.Learn more →](https://amhnationwide.com/30-day-hair-drug-test/)[Hair ETG Alcohol TestAlso need alcohol testing? The hair ETG test screens for alcohol use, and can be added to the same collection.Learn more →](https://amhnationwide.com/etg-and-peth/) Frequently Asked Questions ## Common Questions Hair follicle tests generally cannot detect drug use within the first 5 to 7 days after consumption because hair needs time to grow above the scalp. Detection begins once the hair containing drug metabolites emerges from the scalp. Hair color and type can influence drug metabolite incorporation slightly, but accredited labs account for these variables. The test remains reliable across hair types. Results typically return within 3 to 5 business days after the lab receives the hair sample. Non-negative screens undergo additional review by a certified Medical Review Officer. Chemical treatments may reduce drug metabolite levels in hair but do not guarantee a negative result. Labs are experienced in interpreting such samples. Hair follicle tests provide a longer detection window, up to 90 days, compared to urine tests which detect recent use typically within days. Both have specific applications. AMH Nationwide provides lab orders and directs you to a nearby collection site. Call (877) 731-6362 to schedule your hair follicle drug test or get more information. Sources • [SAMHSA – Mandatory Guidelines for Federal Workplace Drug Testing Programs](https://www.samhsa.gov/workplace/drug-testing) • [U.S. DOT – 49 CFR Part 40 – Procedures for Transportation Workplace Drug and Alcohol Testing Programs](https://www.transportation.gov/odapc/part40) • [CDC – National Center for Health Statistics – Drug Use FastStats](https://www.cdc.gov/nchs/fastats/drug-use.htm) • [Quest Diagnostics – Employer Solutions, Hair Testing Methodology](https://www.questdiagnostics.com/) • [LabCorp – Occupational Testing Services](https://www.labcorp.com/) ## Ready to get started? AMH Nationwide provides the lab order and arranges collection nationwide. Every non-negative result reviewed by a certified Medical Review Officer. Call (877) 731-6362 or contact us. [Call (877) 731-6362](tel:+18777316362)[Contact Us](https://amhnationwide.com/contact-us/) --- **Need a drug, alcohol, HIV or STD test?** AMH Nationwide is a national lab testing agency operating since 2004, with more than 20,000 collection sites across the United States. Hair, urine, fingernail and blood testing, panels from 5 through 19, for individuals and employers. - Call: (877) 731-6377 - Find a collection site: https://amhnationwide.com/locations/ - Full page: https://amhnationwide.com/how-long-does-a-hair-follicle-drug-test/