--- title: "how long does methamphetamine stay in hair" description: "How long does methamphetamine stay in hair? Hair drug tests detect it up to 90 days or more. Call (877) 731-6362 for reliable lab testing info." author: "AMH Nationwide" date: "2026-08-28" tags: ["how long does methamphetamine stay in hair"] canonical: "https://amhnationwide.com/how-long-does-methamphetamine-stay-in-hair/" last_updated: "2026-08-31" --- # how long does methamphetamine stay in hair **By AMH Nationwide** | August 28, 2026 How long does methamphetamine stay in hair? Hair drug tests detect it up to 90 days or more. Call (877) 731-6362 for reliable lab testing info. --- How long does methamphetamine stay in hair? Hair drug tests can detect methamphetamine for approximately 90 days after use due to drug incorporation into hair shafts. Factors such as hair growth rate, cosmetic treatments, and individual metabolism influence detection. AMH Nationwide uses five national lab networks with certified Medical Review Officers to ensure accurate results. Call (877) 731-6362. [DETECTION WINDOW](https://amhnationwide.com/hair-follicle-drug-test-detection-window/) ## How long can methamphetamine be detected in hair samples? Methamphetamine typically remains detectable in hair for up to 90 days or longer after use. Hair grows on average around 1 centimeter per month, and standard testing analyzes the first 1.5 inches of hair closest to the scalp to cover approximately a three-month period. This time frame is consistent across scientific literature and forensic toxicology guidelines. Unlike [urine](https://amhnationwide.com/urine-drug-testing/) or blood tests that detect recent use within hours or days, hair tests provide a longer retrospective window. This extended detection window is due to drugs being deposited in the hair matrix as it forms in the follicle. Methamphetamine molecules become trapped inside the hair shaft, preserving a historical record of use. INCORPORATION SCIENCE ## How does methamphetamine incorporate into hair and how is it measured? Methamphetamine is incorporated into hair through the bloodstream supplying the hair follicle during hair formation. The drug and its metabolites bind to melanin and keratin proteins within the hair shaft. This incorporation reflects systemic exposure to the drug rather than external contamination. Testing labs such as those used by AMH Nationwide employ highly sensitive methods like gas chromatography-mass spectrometry (GC-MS) or liquid chromatography-tandem mass spectrometry (LC-MS/MS) following hair sample preparation. These tests detect methamphetamine at cutoff levels defined by [SAMHSA](https://www.samhsa.gov/workplace/drug-testing) guidelines, typically 0.1 ng/mg for screening and 0.05 ng/mg for confirmation. Each non-negative result undergoes medical review by a certified Medical Review Officer (MRO) who evaluates the findings considering possible external contamination or legitimate prescriptions. COMMON MISCONCEPTIONS ## Does washing or bleaching hair remove methamphetamine traces? A frequent myth is that washing, bleaching, or chemically treating hair can eliminate methamphetamine residues. In reality, the drug is embedded inside the hair cortex, not just on the surface. Cosmetic treatments may degrade some hair structure or superficially reduce drug concentration but do not fully remove incorporated substances. Research shows that while hair treatments can alter test sensitivity slightly, accredited laboratories apply sample preparation protocols designed to remove external contaminants while preserving internal drug content. Consequently, methamphetamine remains detectable despite cosmetic alterations. TEST RELIABILITY ## How reliable are hair tests for methamphetamine detection? Hair testing for methamphetamine is highly reliable when conducted by accredited labs following SAMHSA and CAP standards. AMH Nationwide routes samples through five national laboratory networks: [Quest Diagnostics](https://www.questdiagnostics.com/), [LabCorp](https://www.labcorp.com/), Omega Labs, United States Drug Testing Labs, and ExperTox. This network ensures standardized procedures and rigorous quality control. All initial positive screens are confirmed with sensitive mass spectrometry methods, and results are reviewed by a certified Medical Review Officer. These steps minimize false positives due to environmental exposure or lab errors. The use of hair testing is preferred in contexts requiring a longer detection window such as employment screening, legal cases, or [probation](https://amhnationwide.com/hair-follicle-drug-test-probation/) monitoring. ## To Arrange Methamphetamine Hair Testing Call (877) 731-6362 Contact AMH Nationwide to obtain a lab order directing you to a certified collection site. Test results are reviewed by a Medical Review Officer for accuracy and reliability. [Call (877) 731-6362](tel:+18777316362)[Contact Us](https://amhnationwide.com/contact-us/) FACTORS AFFECTING DETECTION ## What factors influence how long methamphetamine stays in hair? While the average detection window is around 90 days, several factors affect how methamphetamine appears in hair samples: • Hair growth rate varies among individuals, potentially altering the detection period. • Hair color and melanin content influence drug binding; darker hair may accumulate more drug. • Frequency and amount of drug use impact concentration levels within the hair. • External contamination is accounted for by laboratory washing procedures but can complicate interpretation. • Use of hair treatments may slightly reduce detected levels but does not eliminate methamphetamine from the hair shaft. TESTING PROCEDURE ## How does AMH Nationwide conduct methamphetamine hair testing? AMH Nationwide provides lab orders directing individuals or organizations to one of more than 20,000 nationwide collection sites. There is no online ordering; all collections are supervised to ensure chain of custody. Samples are sent to one of five national lab networks: Quest Diagnostics, LabCorp, Omega Labs, United States Drug Testing Labs, or ExperTox. These labs employ SAMHSA-aligned testing protocols for hair specimens. After testing, every non-negative methamphetamine result is reviewed by a certified Medical Review Officer to confirm accuracy and rule out alternative explanations. This process supports defensible, scientifically valid results for employers, courts, and other requesters. COMPARISON ## How does hair testing for methamphetamine compare to other specimen types? | Specimen Type | Methamphetamine Detection Window | | --- | --- | | Urine | 1 to 4 days (up to 7 days for heavy use) | | Blood | 12 to 24 hours | | Saliva | 1 to 3 days | | Hair | Up to 90 days or longer | Hair testing offers the longest detection window and is less susceptible to short-term fluctuations or attempts to adulterate the sample compared to urine or saliva. This makes it valuable for understanding long-term methamphetamine exposure. 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 No. Hair testing reflects drug use only after the hair containing drug deposits emerges from the scalp, which takes about 5 to 7 days. Therefore, very recent use will not be detected immediately. Yes. Hair color and texture can influence drug binding. Darker hair with more melanin may bind higher drug concentrations, while very light or chemically treated hair may yield lower levels. Yes. Hair testing methods used by AMH Nationwide labs comply with SAMHSA, CAP, and CLIA standards. While hair testing is not used for federally regulated DOT safety-sensitive testing, it is acceptable for other employment and legal purposes. Laboratory washing procedures remove external contaminants, reducing false positives. Medical Review Officers also evaluate results to distinguish contamination from ingestion. Typically, test results are available within 3 to 7 business days after the sample reaches the laboratory. Exact timing depends on the lab and testing panel. Yes. Hair testing can detect single or infrequent methamphetamine use, but lower concentration levels may be near detection limits. Confirmatory testing and MRO review ensure accurate interpretation. 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-does-methamphetamine-stay-in-hair/