--- title: "What does a hair follicle test for" description: "Learn what does a hair follicle test for with reliable drug detection over 90 days. Understand the process and drugs tested. Call (877) 731-6362 for details." author: "AMH Nationwide" date: "2026-08-28" tags: ["what does a hair follicle test for", "what does a hair follicle test for | what does a hair follicle test test for | what does hair follicle drug test test for | what does a hair follicle drug test test for | what drugs does hair follicle test for | what does a hair drug screen test for | what does a hair drug test test for | what drugs does a hair follicle test for | what does hair follicle test for | how does a hair follicle drug test"] canonical: "https://amhnationwide.com/what-does-a-hair-follicle-test-for/" last_updated: "2026-08-28" --- # What does a hair follicle test for **By AMH Nationwide** | August 28, 2026 Learn what does a hair follicle test for with reliable drug detection over 90 days. Understand the process and drugs tested. Call (877) 731-6362 for details. --- What does a hair follicle test for? This test detects drug use by analyzing hair samples for drug metabolites, covering approximately 90 days of use. It is used by employers, courts, and individuals for accurate long-term drug screening. Collection is done at national lab sites. Call (877) 731-6362. OVERVIEW ## What does a hair follicle test for? A hair follicle test detects the presence of drug metabolites embedded in the hair shaft, reflecting drug use over the past 90 days. It is commonly used to screen for various substances including opioids, cocaine, amphetamines, cannabinoids, and PCP. The test analyzes a small hair sample, typically 1.5 inches long, which represents about three months of hair growth. This method provides a longer [detection window](https://amhnationwide.com/hair-follicle-drug-test-detection-window/) than [urine](https://amhnationwide.com/urine-drug-testing/) or saliva tests. DRUGS TESTED ## What drugs does a hair follicle test for? Hair follicle drug tests screen for multiple drug classes, including: The standard panel includes opiates, cocaine, amphetamines, marijuana (THC), and phencyclidine (PCP). Additional panels may test for benzodiazepines, barbiturates, methadone, and synthetic opioids depending on the requester’s requirements. Opiates: morphine, codeine, heroin Cocaine and its metabolites Amphetamines and methamphetamine THC from marijuana Phencyclidine (PCP) Optional: benzodiazepines, barbiturates, methadone, synthetic opioids TESTING PROCESS ## How does a hair follicle drug test work? During a hair follicle drug test, a small sample of hair is collected close to the scalp. The sample is 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. The labs analyze the hair for drug metabolites that have been absorbed into the hair shaft from the bloodstream. A certified Medical Review Officer reviews all non-negative results to confirm findings and rule out legitimate medical explanations. DETECTION WINDOW ## What is the detection window for a hair follicle drug test? Hair follicle tests detect drug use typically within a 90-day window. This is because hair grows approximately 0.5 inches per month and the test examines about 1.5 inches of hair closest to the scalp. This long detection window makes hair testing useful for employers, courts, and [probation](https://amhnationwide.com/hair-follicle-drug-test-probation/) programs seeking to identify patterns of drug use rather than recent use alone. ## Arrange Hair Follicle Drug Testing with AMH Nationwide To schedule a hair follicle drug test, call (877) 731-6362. AMH Nationwide directs you to collection sites affiliated with major national labs ensuring accurate and certified testing. [Call (877) 731-6362](tel:+18777316362)[Contact Us](https://amhnationwide.com/contact-us/) COMPARISON ## How does a hair follicle test compare to urine drug tests? Hair follicle tests provide a longer detection window than urine tests but do not detect very recent drug use within the past 1-7 days. Urine tests detect recent drug use typically within 1-3 days for most substances. Hair tests detect use over months but cannot specify the exact timing of use within that period. | Test Type | Detection Window | | --- | --- | | Hair Follicle Test | Up to 90 days | | Urine Drug Test | 1 to 3 days (varies by drug) | APPLICATIONS ## Who orders hair follicle drug tests and why? Employers use hair follicle tests for [pre-employment](https://amhnationwide.com/pre-employment-hair-testing/) screening and random testing to identify long-term drug use. Courts and probation agencies use them to monitor compliance over extended periods. Individuals may also request hair testing for personal reasons or as part of legal or employment requirements. AMH Nationwide facilitates lab orders and directs clients to collection sites nationwide. 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 Yes, hair follicle tests can detect even a single use of many drugs because metabolites become embedded in hair. However, detection depends on hair length and timing relative to drug use. Hair color can influence drug metabolite incorporation due to melanin content, but accredited labs use validated methods to minimize bias and provide reliable results. Results typically take 3 to 5 business days after the lab receives the sample. Non-negative results undergo Medical Review Officer evaluation, which may add additional time. Hair follicle testing for alcohol is possible but not standard. Specialized tests detect [ethyl glucuronide](https://amhnationwide.com/hair-etg-alcohol-test/) (EtG) in hair to indicate chronic alcohol use rather than occasional drinking. No, DOT-regulated drug testing requires federally certified urine testing under [49 CFR Part 40](https://www.transportation.gov/odapc/part40). Hair tests are used for non-DOT roles and other screening purposes. Contact AMH Nationwide by calling (877) 731-6362. We provide the lab order and direct you to one of over 20,000 nationwide collection sites affiliated with major national labs. 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/what-does-a-hair-follicle-test-for/