--- title: "Do all drugs show up in hair follicle test" description: "Do all drugs show up in hair follicle test? Hair follicle testing detects many drugs over months. Learn what shows up and call (877) 731-6362 for details." author: "AMH Nationwide" date: "2026-08-28" tags: ["do all drugs show up in hair follicle test", "do all drugs show up in hair follicle test | what all shows up on a hair follicle drug test | what all drugs show up on a hair follicle test | what all shows up in a hair follicle drug test | what all shows up on hair follicle drug test"] canonical: "https://amhnationwide.com/do-all-drugs-show-up-in-hair-follicle-test/" last_updated: "2026-08-28" --- # Do all drugs show up in hair follicle test **By AMH Nationwide** | August 28, 2026 Do all drugs show up in hair follicle test? Hair follicle testing detects many drugs over months. Learn what shows up and call (877) 731-6362 for details. --- Do all drugs show up in hair follicle test? Hair follicle testing detects many commonly abused drugs over a 90-day period but does not detect all substances. This test identifies drug metabolites embedded in hair shafts, providing a long detection window. Call (877) 731-6362 to schedule or learn more. OVERVIEW ## Do all drugs show up in hair follicle test? Hair follicle drug tests detect a wide range of drugs but do not identify every drug. The test analyzes hair samples for drug metabolites that accumulate in the hair shaft after drug use. Commonly detected drugs include cocaine, marijuana (THC), opiates, amphetamines, methamphetamines, phencyclidine (PCP), and some prescription medications. However, certain drugs may not be reliably detected due to their chemical properties, usage patterns, or low incorporation into hair. This makes hair follicle testing a strong but not all-encompassing method for drug detection. DETECTION LIST ## What all shows up on a hair follicle drug test? Hair follicle tests typically screen for these drug classes: The panel selection can vary depending on the requester and laboratory capabilities. AMH Nationwide routes collections through five national lab networks: [Quest Diagnostics](https://www.questdiagnostics.com/), [LabCorp](https://www.labcorp.com/), Omega Labs, United States Drug Testing Labs, and ExperTox. Amphetamines and Methamphetamines: Includes drugs like Adderall and meth. Cocaine and its metabolites. Opiates: Such as heroin, morphine, codeine, and oxycodone. Phencyclidine (PCP). Marijuana (THC and metabolites). Benzodiazepines: Some panels include drugs like diazepam and alprazolam. Barbiturates: Occasionally tested depending on the panel. TECHNICAL DETAILS ## How does hair follicle testing detect drugs? Hair follicle testing detects drugs by identifying their metabolites deposited in the hair shaft from the bloodstream. After drug use, metabolites enter the hair follicle and become trapped within the hair structure as it grows. This method allows detection of drug use over approximately 90 days, as hair grows about 0.5 inches per month. A standard 1.5-inch hair sample can reveal drug use history for about three months. Hair testing is not effective for detecting very recent drug use (within a few days) due to the time required for the hair to grow out from the follicle. LIMITATIONS ## Are there drugs that do not show up on hair follicle tests? Yes. Some drugs either do not incorporate well into hair or are not included in standard test panels. For example, alcohol is not detected by hair follicle drug tests but requires specialized testing of hair for [ethyl glucuronide](https://amhnationwide.com/hair-etg-alcohol-test/) (EtG). Some synthetic drugs or newer psychoactive substances may not be detected if the test panel does not specifically include them. Additionally, passive exposure rarely causes positive results due to the way hair testing analyzes metabolites internally incorporated into hair. Testing limitations depend on the laboratory panel and the chemical nature of the drug. ## Need Accurate Hair Follicle Drug Testing? Call (877) 731-6362 to schedule your hair follicle drug test or to speak with a specialist about detection panels and testing procedures. [Call (877) 731-6362](tel:+18777316362)[Contact Us](https://amhnationwide.com/contact-us/) EMPLOYER AND LEGAL USE ## Who orders hair follicle drug tests and why? Employers, courts, [probation](https://amhnationwide.com/hair-follicle-drug-test-probation/) officers, and individuals request hair follicle testing to verify drug abstinence or detect past drug use over extended periods. It is often used when a long [detection window](https://amhnationwide.com/hair-follicle-drug-test-detection-window/) is required or when [urine](https://amhnationwide.com/urine-drug-testing/) testing is insufficient. Hair testing is useful for safety-sensitive positions and legal cases but is not DOT-regulated for hair. DOT-regulated tests require urine testing under the federally certified urine protocol ([49 CFR Part 40](https://www.transportation.gov/odapc/part40)). AMH Nationwide facilitates the lab order and directs the requester to one of 20,000+ nationwide collection sites to ensure proper sample collection. TESTING PROCESS ## How is hair follicle testing conducted through AMH Nationwide? AMH Nationwide provides the lab order and directs the requester or donor to a local collection site. The hair sample is collected close to the scalp to ensure analysis of recent hair growth. Samples are sent to one of five national lab networks: Quest Diagnostics, LabCorp, Omega Labs, United States Drug Testing Labs, or ExperTox for analysis. Results are reviewed by a certified Medical Review Officer to confirm non-negative findings before reporting. There is no online ordering. To initiate testing, call (877) 731-6362. 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 Hair follicle tests detect drug metabolites incorporated into hair over time. A single use may be detected if enough drug is present to deposit metabolites in the hair shaft, but detection depends on dosage, hair growth, and timing. Hair follicle testing can detect drug use typically 7-10 days after use, covering approximately 90 days of history depending on hair length collected. Hair color can influence drug binding slightly due to melanin content, but modern testing accounts for this, and it does not prevent accurate detection. Some prescription drugs, such as certain opiates and benzodiazepines, can be detected if included in the test panel. This depends on the specific panel ordered. Passive exposure is unlikely to cause a positive result because hair testing detects metabolites formed inside the body, not external contamination. DOT regulations require urine testing under 49 CFR Part 40 for safety-sensitive roles. Hair follicle testing is used for non-DOT testing purposes. 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/do-all-drugs-show-up-in-hair-follicle-test/