--- title: "How long do drugs stay in hair follicles" description: "How long do drugs stay in hair follicles varies by drug and hair length. Hair testing offers a 90-day detection window. Call (877) 731-6362 to schedule testing." author: "AMH Nationwide" date: "2026-08-28" tags: ["how long do drugs stay in hair follicles", "how long do drugs stay in hair follicles | how long do drugs stay in your hair follicles"] canonical: "https://amhnationwide.com/how-long-do-drugs-stay-in-hair-follicles/" last_updated: "2026-08-28" --- # How long do drugs stay in hair follicles **By AMH Nationwide** | August 28, 2026 How long do drugs stay in hair follicles varies by drug and hair length. Hair testing offers a 90-day detection window. Call (877) 731-6362 to schedule testing. --- How long do drugs stay in hair follicles depends on the drug type and hair length, typically up to 90 days. Hair follicle drug testing detects long-term use rather than recent exposure. AMH Nationwide routes collections through five national labs with certified Medical Review Officer review. Call (877) 731-6362. [DETECTION WINDOW](https://amhnationwide.com/hair-follicle-drug-test-detection-window/) ## How long do drugs stay in hair follicles? Drugs can stay in hair follicles for up to 90 days, making hair follicle testing effective for detecting drug use over approximately three months. The detection window depends on hair length and the rate of hair growth, which averages about 0.5 inches per month. Hair follicle testing identifies drug metabolites deposited in the hair shaft from the bloodstream during hair formation. Unlike [urine](https://amhnationwide.com/urine-drug-testing/) or saliva testing, which detect recent use, hair testing reflects a longer history of drug intake. Typical detection window: up to 90 days Hair growth rate: about 0.5 inches per month Sample length usually tested: 1.5 inches of hair Detects drug metabolites, not the drug itself TEST SPECIFICS ## What drugs can be detected in hair follicles? Hair follicle testing can detect a wide range of drugs including marijuana, cocaine, opiates, amphetamines, methamphetamines, phencyclidine (PCP), and certain prescription medications. The test identifies drug metabolites incorporated into the hair shaft. Because hair testing samples are analyzed in accredited labs such as [Quest Diagnostics](https://www.questdiagnostics.com/), [LabCorp](https://www.labcorp.com/), Omega Labs, United States Drug Testing Labs, and ExperTox, results are reliable and reviewed by certified Medical Review Officers to confirm accuracy. Marijuana (THC metabolites) Cocaine and its metabolites Opiates such as morphine and codeine Amphetamines and methamphetamines Phencyclidine (PCP) Certain prescription drugs depending on the panel TESTING PROCESS ## How is hair follicle drug testing performed? A small sample of hair, typically 1.5 inches long, is collected close to the scalp from the crown area. This length corresponds to roughly 90 days of hair growth and drug exposure. AMH Nationwide directs test requesters to one of 20,000+ collection sites nationwide that partner with five national lab networks for comprehensive testing. There is no online ordering; all tests require contacting AMH directly. After collection, samples are sent to a certified lab where they undergo immunoassay screening and confirmatory gas chromatography-mass spectrometry (GC-MS) or liquid chromatography-tandem mass spectrometry (LC-MS/MS). RESULTS & RELIABILITY ## How reliable is hair follicle drug testing? Hair follicle drug testing is highly reliable for detecting drug use over the past 90 days. It is less susceptible to adulteration or substitution compared to urine testing. However, it does not detect very recent drug use within the past week. Every non-negative result undergoes review by a certified Medical Review Officer (MRO) to verify findings and consider legitimate medical explanations before reporting final results. AMH Nationwide works with [SAMHSA](https://www.samhsa.gov/workplace/drug-testing)-aligned, CAP, and CLIA-accredited labs ensuring consistent quality and accuracy. ## Schedule Hair Follicle Drug Testing Today To arrange hair follicle drug testing with AMH Nationwide and access reliable results from five national lab networks, call (877) 731-6362. Our certified Medical Review Officers review all non-negative results for accuracy. [Call (877) 731-6362](tel:+18777316362)[Contact Us](https://amhnationwide.com/contact-us/) LIMITATIONS ## Can hair follicle testing detect one-time drug use or passive exposure? Hair follicle testing is more effective at identifying repeated or chronic drug use rather than a single one-time use. Very low-level or isolated exposures may not produce detectable metabolite levels in hair. Passive exposure, such as environmental contact with drug smoke, is unlikely to produce positive hair test results due to the need for metabolites to be incorporated into the hair via the bloodstream. Testing sensitivity and cutoff levels are designed to minimize false positives from incidental exposure. EMPLOYER & LEGAL USE ## Who orders hair follicle drug testing and why? Employers commonly use hair follicle testing for [pre-employment](https://amhnationwide.com/pre-employment-hair-testing/) screening, random testing, and post-incident investigations to evaluate long-term drug use history. Courts, [probation](https://amhnationwide.com/hair-follicle-drug-test-probation/) offices, and legal entities may request hair testing to monitor compliance with drug-related conditions. Individuals may also request hair follicle tests for personal monitoring or verification purposes. AMH Nationwide facilitates access by directing to collection sites and accredited labs, but does not provide online ordering. 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 Results typically take 5 to 7 business days after the lab receives the hair sample. Complex panels or confirmatory testing may extend the timeframe slightly. No. Hair testing generally cannot detect drug use within the past 7 days because it takes time for drugs to incorporate into the hair shaft as it grows. Hair treatments can reduce drug metabolite concentrations but accredited labs use methods to account for this. Extremely damaged hair may require alternative sample collection. Hair color can influence drug binding slightly, but testing labs use standardized protocols to minimize bias and ensure accurate detection regardless of hair color. If hair is too short, collection sites may collect body hair or recommend an alternative test type. Body hair has a longer and less precise detection window. Standard hair drug tests do not detect alcohol. Specialized tests can detect alcohol metabolites like [ethyl glucuronide](https://amhnationwide.com/hair-etg-alcohol-test/) (EtG) in hair but require specific ordering. 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-do-drugs-stay-in-hair-follicles/