--- title: "How long does a hair follicle drug test last" description: "How long does a hair follicle drug test last? Hair follicle drug tests detect drug use for up to 90 days. Call (877) 731-6362 for testing info." author: "AMH Nationwide" date: "2026-08-28" tags: ["how long does a hair follicle drug test last", "how long does a hair follicle drug test last | how long does drugs last in hair follicle test | how long does drug test hair follicle last | how long does hair follicle drug test last"] canonical: "https://amhnationwide.com/how-long-does-a-hair-follicle-drug-test-last/" last_updated: "2026-08-28" --- # How long does a hair follicle drug test last **By AMH Nationwide** | August 28, 2026 How long does a hair follicle drug test last? Hair follicle drug tests detect drug use for up to 90 days. Call (877) 731-6362 for testing info. --- How long does a hair follicle drug test last? Hair follicle drug tests typically detect drug use within the past 90 days due to the growth cycle of hair. These tests provide a longer detection window than urine or saliva tests. AMH Nationwide coordinates testing through major national labs. Call (877) 731-6362 to schedule or learn more. [DETECTION WINDOW](https://amhnationwide.com/hair-follicle-drug-test-detection-window/) ## How long does a hair follicle drug test last for detecting drugs? A hair follicle drug test typically detects drug use for up to 90 days prior to sample collection. This extended detection window is due to the way drugs are deposited and retained in the hair shaft as it grows. Unlike [urine](https://amhnationwide.com/urine-drug-testing/) or saliva tests that detect recent use within days, hair testing reflects drug exposure over several months, making it useful for employers, courts, or [probation](https://amhnationwide.com/hair-follicle-drug-test-probation/) officers who require a longer-term overview of drug use. TEST PROCESS ## How does a hair follicle drug test work to detect drug use? Hair follicle drug tests analyze a small sample of hair, usually about 1.5 inches from the scalp, which represents approximately 90 days of hair growth. Drugs and their metabolites enter the hair follicle from the bloodstream and become trapped within the hair shaft. The collected hair 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. Each lab follows strict [SAMHSA](https://www.samhsa.gov/workplace/drug-testing)-aligned protocols, with all non-negative results reviewed by a certified Medical Review Officer. Sample length: 1.5 inches (about 90 days of growth) Drugs detected include marijuana, cocaine, opiates, methamphetamine, PCP, and others Testing is highly reliable and resistant to adulteration Non-negative results reviewed by certified Medical Review Officer DRUGS DETECTED ## Which drugs can a hair follicle drug test detect and for how long? Hair follicle drug tests detect a broad range of substances. The detection window for most drugs is up to 90 days, reflecting the period of hair growth sampled. Common drugs detected include marijuana (THC), cocaine, opiates (heroin, morphine, codeine), amphetamines, methamphetamine, PCP, and sometimes synthetic opioids or benzodiazepines depending on the test panel. Marijuana (THC): up to 90 days Cocaine: up to 90 days Opiates: up to 90 days Amphetamines and methamphetamine: up to 90 days PCP: up to 90 days TEST LIMITATIONS ## Can hair follicle drug tests detect one-time or recent drug use? Hair follicle drug tests are less effective at detecting very recent or one-time drug use because it takes 5-7 days for the hair containing drug metabolites to grow above the scalp surface. Therefore, drug use within the past week may not be detected. Hair testing is better suited for identifying patterns of repeated drug use over weeks or months rather than immediate or one-time exposure. ## Schedule Your Hair Follicle Drug Test Today To learn more about how long a hair follicle drug test lasts or to arrange testing through AMH Nationwide, call (877) 731-6362. Our experienced team will guide you through the process. [Call (877) 731-6362](tel:+18777316362)[Contact Us](https://amhnationwide.com/contact-us/) PASSIVE EXPOSURE ## Does passive drug exposure affect hair follicle drug test results? Hair follicle drug tests are designed to detect drug metabolites incorporated into the hair from the bloodstream, not just external contamination. While passive exposure to drug smoke or contact can deposit drugs on the hair surface, labs use washing procedures to remove external contaminants. Positive results generally indicate actual drug use rather than incidental exposure. TESTING PROCEDURE ## How does AMH Nationwide handle hair follicle drug testing? AMH Nationwide coordinates hair follicle drug testing by providing lab orders and directing clients to one of 20,000+ nationwide collection sites associated with five major national lab networks. There is no online ordering of tests. All samples are processed under strict federal and industry standards. DOT-regulated safety-sensitive testing requires federally certified urine protocols; hair testing is used for non-DOT roles. Call (877) 731-6362 to arrange testing or obtain more information. 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-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 A hair follicle drug test can detect drug use for up to 90 days prior to sample collection, based on the length of hair analyzed. Hair follicle tests are less sensitive to very recent or one-time drug use because it takes about 5-7 days for drug metabolites to appear in the hair above the scalp. Most hair follicle tests detect common drugs such as marijuana, cocaine, opiates, amphetamines, methamphetamine, and PCP. Some panels may include additional substances. Labs wash hair samples to remove external contaminants, so positive results generally reflect actual drug use rather than passive exposure. AMH Nationwide provides lab orders and directs clients to collection sites linked to five major national labs, with all non-negative results reviewed by certified Medical Review Officers. No. DOT-regulated safety-sensitive testing requires federally certified urine testing protocols. Hair follicle tests are used for non-DOT roles. 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-last/