--- title: "6-Month Hair Drug Test: How It Works | AMH Nationwide" description: "Learn how the 6-month hair drug test works for long-term drug detection. Understand sample collection, lab analysis, and MRO review. Call (877) 731-6362." author: "AMH Nationwide" date: "2026-08-27" tags: ["6-month hair drug test how it works"] canonical: "https://amhnationwide.com/6-month-hair-drug-test-how-it-works/" last_updated: "2026-08-27" --- # 6-Month Hair Drug Test: How It Works | AMH Nationwide **By AMH Nationwide** | August 27, 2026 Learn how the 6-month hair drug test works for long-term drug detection. Understand sample collection, lab analysis, and MRO review. Call (877) 731-6362. --- The 6-month hair drug test how it works involves collecting a small hair sample to detect drug use over the past six months. The sample is analyzed by national labs using screening and confirmation steps with MRO review. Call (877) 731-6362 to schedule your test. OVERVIEW ## What is a 6-month hair drug test and how is the sample collected? A 6-month hair drug test how it works begins with collecting approximately 1.5 inches of hair closest to the scalp, representing up to six months of growth. A small sample, usually about 100 strands, is taken from the crown area using scissors. This collection is non-invasive and requires no special preparation. LAB NETWORKS ## Which labs analyze 6-month hair drug tests and how is the sample processed? The 6-month hair drug test how it works includes routing the collected sample to one of five national labs: [Quest Diagnostics](https://www.questdiagnostics.com/), [LabCorp](https://www.labcorp.com/), Omega Labs, United States Drug Testing Labs, or ExperTox. Each lab follows strict protocols for hair testing to ensure accuracy and reliability. Sample received and logged into lab system Hair is washed to remove external contaminants Drugs are extracted chemically from the hair matrix Initial screening is conducted using immunoassay or mass spectrometry methods ANALYSIS PROCESS ## How does the lab analyze the 6-month hair drug test sample? The 6-month hair drug test how it works involves two main steps: screening and confirmation. The initial screening detects the presence of common drugs or metabolites. If the screening is positive or inconclusive, confirmation testing using gas chromatography-mass spectrometry (GC-MS) or liquid chromatography-tandem mass spectrometry (LC-MS/MS) is performed for definitive results. Screening tests for drugs such as THC, cocaine, opiates, amphetamines, and PCP Confirmation testing validates positive or borderline results Quantitative analysis measures drug concentration levels MRO REVIEW ## What role does the Medical Review Officer (MRO) play in the 6-month hair drug test process? Every non-negative 6-month hair drug test result undergoes review by a certified Medical Review Officer. The MRO evaluates lab findings, verifies testing integrity, and interviews the individual if necessary to rule out legitimate medical explanations before releasing a final report. ## Ready to Schedule Your 6-Month Hair Drug Test? Contact AMH Nationwide to arrange your test at a nearby collection site. Call (877) 731-6362 to begin. [Call (877) 731-6362](tel:+18777316362)[Contact Us](https://amhnationwide.com/contact-us/) TESTING LIMITATIONS ## What are the detection windows and limitations of the 6-month hair drug test? The 6-month hair drug test how it works detects drug use within approximately the past six months based on hair growth rates. However, hair treatments, color, and individual hair growth variability can affect detection. It does not detect very recent drug use within the past week as hair has not yet grown out. Detects drug use up to six months prior Cannot detect use within 7 days before collection Hair treatments may reduce detection sensitivity COLLECTION SITES ## How does AMH Nationwide coordinate sample collection for the 6-month hair drug test? AMH Nationwide provides the lab order and directs the requester to an authorized collection site near the individual. Collection sites follow standardized procedures for hair sampling to maintain chain of custody. AMH does not offer online ordering; scheduling requires calling (877) 731-6362. 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 Approximately 1.5 inches of hair closest to the scalp, about 100 strands, is collected to represent six months of drug use history. The test screens for common drugs including THC, cocaine, opiates, amphetamines, and PCP, but detection depends on drug type and lab protocols. No. DOT safety-sensitive testing requires federally certified [urine](https://amhnationwide.com/urine-drug-testing/) tests under [49 CFR Part 40](https://www.transportation.gov/odapc/part40). Hair tests are used for non-DOT roles. A positive or inconclusive screening triggers confirmation testing with advanced mass spectrometry methods to verify results. Hair treatments and color can influence detection sensitivity, but labs apply methods to minimize these effects. Turnaround times vary by lab but typically results are available within several days after sample receipt and analysis. 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/6-month-hair-drug-test-how-it-works/