--- title: "9-Month Hair Drug Test: How It Works | AMH Nationwide" description: "Learn how the 9-month hair drug test works for long-term substance detection. Understand sample collection, lab analysis, and MRO review. Call (877) 731-6362." author: "AMH Nationwide" date: "2026-08-27" tags: ["9-month hair drug test how it works"] canonical: "https://amhnationwide.com/9-month-hair-drug-test-how-it-works/" last_updated: "2026-08-27" --- # 9-Month Hair Drug Test: How It Works | AMH Nationwide **By AMH Nationwide** | August 27, 2026 Learn how the 9-month hair drug test works for long-term substance detection. Understand sample collection, lab analysis, and MRO review. Call (877) 731-6362. --- The 9-month hair drug test how it works involves collecting a small hair sample, which is then analyzed by national labs for drug metabolites covering up to nine months. Screening, confirmation, and Medical Review Officer review ensure accuracy. Call (877) 731-6362 to arrange testing and collection. OVERVIEW ## What is a 9-month hair drug test and how does it work? A 9-month hair drug test works by analyzing a small hair sample to detect drug use over approximately nine months. Hair grows about half an inch per month, so a 4.5-inch hair sample captures drug metabolites deposited as hair forms. This test identifies drug use in a longer [detection window](https://amhnationwide.com/hair-follicle-drug-test-detection-window/) than [urine](https://amhnationwide.com/urine-drug-testing/) or saliva tests by measuring the presence of substances embedded in the hair shaft. COLLECTION ## How is the hair sample collected for the 9-month hair drug test? The hair sample is collected by a trained collector at a designated site. A small bundle of hair, typically from the crown of the head, is cut close to the scalp to capture the most recent 9-month growth. The sample size generally requires about 100 strands or the equivalent thickness of a pencil. The collection is non-invasive, painless, and requires no special preparation. If head hair is unavailable, body hair may be used but with limitations on detection accuracy. Sample length: About 4.5 inches to cover 9 months Sample location: Crown of the head preferred Sample quantity: Approximately 100 strands Collection method: Scissors cutting close to scalp LAB PROCESSING ## What happens to the hair sample after collection? After collection, the sample is securely 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. These labs perform the analysis using standardized scientific protocols. The labs first perform an initial screening to detect the presence of drug metabolites. If the screen is positive or inconclusive, a confirmation test using gas chromatography-mass spectrometry (GC-MS) or liquid chromatography-tandem mass spectrometry (LC-MS/MS) is conducted to verify the results. Labs involved: Quest Diagnostics, LabCorp, Omega Labs, United States Drug Testing Labs, ExperTox Initial screening: Immunoassay or equivalent method Confirmation testing: GC-MS or LC-MS/MS for accuracy ANALYTICAL DETAILS ## How does the lab analyze the hair for drug metabolites? The lab washes the hair sample to remove external contaminants before analysis. Next, they extract drug metabolites embedded inside the hair shaft using chemical solvents. The extracted compounds undergo screening for common drugs such as cocaine, opiates, amphetamines, cannabinoids, and phencyclidine. Confirmatory testing quantifies the metabolite levels to ensure specificity and rule out false positives. Step 1: Washing to eliminate external contamination Step 2: Chemical extraction of internal metabolites Step 3: Screening for multiple drug classes Step 4: Confirmation to quantify and verify results ## Arrange Your 9-Month Hair Drug Test Collection To schedule a 9-month hair drug test collection at a certified site and ensure accurate processing through national labs, call (877) 731-6362 today. [Call (877) 731-6362](tel:+18777316362)[Contact Us](https://amhnationwide.com/contact-us/) REVIEW ## What role does the Medical Review Officer (MRO) play in the 9-month hair drug test? Every non-negative hair drug test result is reviewed by a certified Medical Review Officer (MRO). The MRO evaluates the lab findings alongside any medical explanations or prescription information provided by the tested individual. This review ensures that legitimate medical use of substances is differentiated from illicit drug use, maintaining accuracy and fairness in result interpretation. ADDITIONAL INFORMATION ## Why is the 9-month hair drug test preferred over other testing methods? The 9-month hair drug test offers a longer detection window compared to urine or saliva tests, which typically detect only recent drug use within days or weeks. It is especially useful when a comprehensive history of drug use is required. The test is non-invasive and difficult to adulterate compared to other specimen types. | Test Type | Detection Window | | --- | --- | | Urine Drug Test | 1 to 7 days | | Saliva Drug Test | 1 to 3 days | | 9-Month Hair Drug Test | Up to 9 months | Because hair testing cannot detect very recent drug use (within the past week), it complements rather than replaces shorter-term tests in some scenarios. 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 A small sample about 4.5 inches long and roughly the diameter of a pencil is collected, typically from the crown of the head, to cover drug use over nine months. Yes, body hair can be used if head hair is insufficient, but it may affect the accuracy and detection window of the test. The test screens for common drugs such as cocaine, opiates, amphetamines, cannabinoids, and phencyclidine, but panels may vary by lab. Contact us for specifics. Hair treatments like dyeing or bleaching may reduce metabolite concentration but do not completely invalidate the test. Labs account for this during analysis. Results typically return within several days after sample collection, depending on lab workload and confirmation testing requirements. The 9-month hair drug test is for non-DOT safety-sensitive roles. DOT-regulated testing requires federally certified urine protocols under [49 CFR Part 40](https://www.transportation.gov/odapc/part40). 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/9-month-hair-drug-test-how-it-works/