How long do drugs stay in hair follicles
How Long Do Drugs Stay in Hair Follicles for Reliable Testing Results
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.
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 or saliva testing, which detect recent use, hair testing reflects a longer history of drug intake.
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, LabCorp, Omega Labs, United States Drug Testing Labs, and ExperTox, results are reliable and reviewed by certified Medical Review Officers to confirm accuracy.
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).
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-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.
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.
Who orders hair follicle drug testing and why?
Employers commonly use hair follicle testing for pre-employment screening, random testing, and post-incident investigations to evaluate long-term drug use history.
Courts, 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.
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 (EtG) in hair but require specific ordering.
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.