--- title: "How much hair is needed for a drug test" description: "Learn how much hair is needed for a drug test and hair follicle test at AMH Nationwide. Accurate collection with certified review. Call (877) 731-6362 today." author: "AMH Nationwide" date: "2026-08-28" tags: ["how much hair is needed for a drug test", "how much hair is needed for a drug test | how much hair is needed for a hair drug test | how much hair is needed for drug test | how much hair is needed for a hair follicle test | how much hair is needed for hair follicle test | how much hair needed for drug test | how much hair is needed for hair follicle drug test"] canonical: "https://amhnationwide.com/how-much-hair-is-needed-for-a-drug-test/" last_updated: "2026-08-28" --- # How much hair is needed for a drug test **By AMH Nationwide** | August 28, 2026 Learn how much hair is needed for a drug test and hair follicle test at AMH Nationwide. Accurate collection with certified review. Call (877) 731-6362 today. --- How much hair is needed for a drug test depends on the testing method; typically, a 1.5-inch hair sample about the diameter of a pencil is required for a hair follicle test. This provides a detection window of up to 90 days. AMH Nationwide routes collections through five national labs with certified Medical Review Officer oversight. Call (877) 731-6362. BASICS ## How much hair is needed for a hair follicle drug test? A standard hair follicle drug test requires approximately 1.5 inches of hair length, taken from close to the scalp, with a diameter roughly equal to a pencil’s width. This amount is generally sufficient to provide a 90-day drug use history. The hair sample is cut from the crown or back of the head where growth is most consistent. PROCESS ## How much hair do they take for a drug test? During collection, a small cluster of hair strands is cut close to the scalp using clean scissors. The sample size is about 100 to 120 strands, ensuring enough material for accurate testing across the required [detection window](https://amhnationwide.com/hair-follicle-drug-test-detection-window/). If the individual has very short hair, body hair may be used as an alternative, but it may affect detection time frames. PREPARATION ## Should I cut my hair before a hair drug test? Cutting your hair before a hair follicle drug test is generally not advisable. The lab needs sufficient length—around 1.5 inches—to analyze drug metabolites incorporated into the hair shaft over time. Cutting hair short may reduce the detection window or lead to insufficient sample size, which might delay results or require retesting. TECHNICAL ## Why is a 1.5-inch hair sample required for a drug test? A 1.5-inch hair sample corresponds to approximately 90 days of hair growth, as hair grows about half an inch per month. This length allows testing laboratories to detect drug metabolites deposited in the hair shaft during this period. Shorter samples provide a shorter detection window, limiting the test’s ability to identify past drug use. ## Ready to Schedule Your Hair Follicle Drug Test? Call (877) 731-6362 to speak with an AMH Nationwide representative. We will guide you through the testing process and direct you to a collection site near you. [Call (877) 731-6362](tel:+18777316362)[Contact Us](https://amhnationwide.com/contact-us/) LAB NETWORKS ## Which labs process hair follicle drug tests for AMH Nationwide? AMH Nationwide directs hair follicle drug test collections to five national lab networks: [Quest Diagnostics](https://www.questdiagnostics.com/), [LabCorp](https://www.labcorp.com/), Omega Labs, United States Drug Testing Labs, and ExperTox. Each lab follows strict chain-of-custody and testing protocols. Every non-negative result is reviewed by a certified Medical Review Officer to ensure accuracy and compliance. ORDERING ## How do I arrange a hair follicle drug test with AMH Nationwide? AMH Nationwide provides the lab order and directs you to a nearby collection site. There is no online ordering available. To arrange a hair follicle drug test or for questions about sample requirements and detection windows, call (877) 731-6362. Pricing varies based on the testing panel and 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 Yes, body hair can be collected if head hair is insufficient. However, body hair has a different growth rate and detection window, which may affect test results and interpretation. Results typically take 3 to 5 business days after the lab receives the sample, depending on the lab network and testing panel selected. Hair treatments like bleaching or dyeing may reduce drug metabolite concentrations but do not guarantee evasion. Labs have methods to detect sample tampering or adulteration. Hair testing reflects drug use over the past 90 days but does not detect very recent use within the last 7 days due to the time required for drug metabolites to incorporate into the hair shaft. No, DOT-regulated safety-sensitive testing requires [urine](https://amhnationwide.com/urine-drug-testing/) collection under the federally certified protocol [49 CFR Part 40](https://www.transportation.gov/odapc/part40). Hair testing is generally used for non-DOT roles. Refusing a drug test may have legal or employment consequences depending on the situation. Always discuss concerns with the requesting party or legal advisor before declining. 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-much-hair-is-needed-for-a-drug-test/