--- title: "12-Month Hair Drug Test: How It Works | AMH Nationwide" description: "Learn how the 12-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: ["12-month hair drug test how it works"] canonical: "https://amhnationwide.com/12-month-hair-drug-test-how-it-works/" last_updated: "2026-08-27" --- # 12-Month Hair Drug Test: How It Works | AMH Nationwide **By AMH Nationwide** | August 27, 2026 Learn how the 12-month hair drug test works for long-term drug detection. Understand sample collection, lab analysis, and MRO review. Call (877) 731-6362. --- The 12-month hair drug test how it works involves collecting a small hair sample from the individual, which is then sent to one of five national labs for analysis. The lab performs initial screening and confirmation testing, followed by review from a certified Medical Review Officer. Call (877) 731-6362 for more details. OVERVIEW ## What is the 12-month hair drug test and how does it work? The 12-month hair drug test how it works centers on detecting drug metabolites embedded in hair follicles, providing a long-term record of drug use. A small sample of hair, typically from the scalp, is collected and analyzed to identify substances used over the past year. This makes it distinct from [urine](https://amhnationwide.com/urine-drug-testing/) or saliva tests that only detect recent use. COLLECTION ## How is the hair sample collected for the 12-month hair drug test? Hair sample collection for the 12-month hair drug test involves cutting a small, pencil-width section of hair close to the scalp. The sample is usually taken from the crown area to ensure the hair is representative of recent growth. This process is minimally invasive and requires no special preparation. Sample size: Approximately 1.5 inches of hair, representing 12 months of growth Collection site: Crown of the head or another suitable area if scalp hair is unavailable Procedure: Cut close to scalp to capture the most recent 12 months Chain of custody: Strict protocols to document sample handling and prevent tampering LAB ANALYSIS ## What happens after the hair sample reaches the lab? Once collected, the 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. The lab begins with an initial screening using immunoassay techniques to detect the presence of drug metabolites. Initial screening identifies potential positive samples Confirmatory testing uses gas chromatography/mass spectrometry (GC/MS) or liquid chromatography-tandem mass spectrometry (LC-MS/MS) Confirmation ensures specificity and eliminates false positives Testing covers a range of drugs including amphetamines, cocaine, opiates, marijuana, and PCP The confirmation step is critical for accuracy, especially in legal or employment contexts. Only confirmed positives are reported as such. MRO REVIEW ## What role does the Medical Review Officer play in the 12-month hair drug test process? Every non-negative result from the lab undergoes review by a certified Medical Review Officer (MRO). The MRO evaluates the test findings in the context of the individual’s medical history and any legitimate prescriptions. This review helps prevent false positives and ensures results are medically accurate and fair. MRO verifies positive results before release Confirms prescription drug use or medical explanations Authorizes final reporting to the requester Provides expert interpretation of complex cases ## Need to understand the 12-month hair drug test process? Contact AMH Nationwide to learn how the 12-month hair drug test works and schedule your collection. Call (877) 731-6362. [Call (877) 731-6362](tel:+18777316362)[Contact Us](https://amhnationwide.com/contact-us/) PROCESS FLOW ## What is the step-by-step process of the 12-month hair drug test how it works? The 12-month hair drug test how it works follows a clear sequence from sample collection to final reporting. | Step | Description | | --- | --- | | 1. Lab Order | Requester contacts AMH Nationwide to initiate testing; no online orders available. | | 2. Sample Collection | Individual visits a collection site where a hair sample is taken. | | 3. Sample Shipment | Sample is securely sent to one of five national labs for analysis. | | 4. Initial Screening | Lab performs immunoassay screening for drug metabolites. | | 5. Confirmatory Testing | Positive screens undergo GC/MS or LC-MS/MS confirmation. | | 6. MRO Review | Certified Medical Review Officer reviews non-negative results. | | 7. Result Reporting | Final results are sent to the requester with MRO interpretation. | LAB NETWORKS ## Which labs perform the 12-month hair drug test analysis? The 12-month hair drug test how it works involves analysis by one of five national lab networks. AMH Nationwide coordinates with these labs to ensure standardized, high-quality testing. Quest Diagnostics LabCorp Omega Laboratories United States Drug Testing Laboratories ExperTox Each lab follows strict federal and industry protocols for hair drug testing, ensuring reliable and legally defensible results. DOT REGULATIONS ## Is the 12-month hair drug test used for DOT-regulated testing? The 12-month hair drug test how it works is not used for DOT-regulated safety-sensitive testing. DOT requires urine testing under the federally certified protocol [49 CFR Part 40](https://www.transportation.gov/odapc/part40). Hair testing is reserved for non-DOT roles and provides a longer [detection window](https://amhnationwide.com/hair-follicle-drug-test-detection-window/). 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 sample about 1.5 inches long and pencil-width thick is collected, usually from the crown of the head, representing approximately 12 months of hair growth. Results typically take several days after sample collection, depending on lab workload and confirmation procedures. The test covers common drugs such as amphetamines, cocaine, opiates, marijuana, and PCP. The exact panel depends on the test ordered. Hair treatments can potentially affect test results, but labs have protocols to minimize interference and maintain accuracy. A certified Medical Review Officer reviews all non-negative results to confirm accuracy and consider medical explanations. No, AMH Nationwide does not offer online ordering. You must call (877) 731-6362 to arrange testing and sample collection. 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/12-month-hair-drug-test-how-it-works/