How far does a hair follicle go back
How Far Does a Hair Follicle Go Back for Drug Detection Benefits
How far does a hair follicle go back is a common question in drug testing. Hair follicle testing can detect drug use up to 90 days prior to collection, providing a longer detection window than urine tests. AMH Nationwide uses five national lab networks and certified Medical Review Officers to ensure accurate results. Call (877) 731-6362.
How far does a hair follicle go back in drug detection?
A hair follicle can provide a drug detection window of up to 90 days. This is because hair grows approximately 0.5 inches per month, and standard hair follicle tests analyze about 1.5 inches of hair closest to the scalp. This allows labs to detect drug metabolites deposited in the hair shaft over the past three months.
How is hair follicle testing performed and processed?
Hair follicle testing involves collecting a small sample of hair from the scalp, usually from the crown area. The sample is sent to one of AMH Nationwide’s five national lab networks: Quest Diagnostics, LabCorp, Omega Labs, United States Drug Testing Labs, or ExperTox.
Each non-negative result undergoes review by a certified Medical Review Officer (MRO) to confirm accuracy and rule out legitimate medical explanations for detected substances.
Who orders hair follicle drug tests and why?
Employers, courts, probation officers, and individuals order hair follicle tests when they need a reliable long-term drug use history. Hair testing is preferred for its ability to detect drug use over months rather than days, making it useful for safety-sensitive or legal situations.
DOT-regulated safety-sensitive testing requires urine testing under 49 CFR Part 40, but hair tests are common for non-DOT roles.
Can hair follicle testing detect one-time or passive drug exposure?
Hair follicle testing reliably detects repeated or chronic drug use rather than a single exposure. Passive exposure is unlikely to produce a positive hair test because drug metabolites must be deposited in the hair shaft internally through the bloodstream.
Therefore, a one-time drug use may not always be detected depending on timing and hair growth.
Schedule Your Hair Follicle Drug Test Today
Call (877) 731-6362 to connect with AMH Nationwide and arrange hair follicle testing through one of our five national lab networks. Accurate detection up to 90 days with certified MRO review.
How reliable and accurate is hair follicle drug testing?
Hair follicle testing is highly reliable when performed by accredited labs such as those used by AMH Nationwide. The use of five national lab networks ensures standardized testing protocols aligned with SAMHSA, CAP, and CLIA guidelines.
Certified Medical Review Officers review all non-negative results to maintain accuracy and integrity.
How do I arrange hair follicle testing with AMH Nationwide?
AMH Nationwide directs test requesters to collection sites within its network of over 20,000 nationwide locations. There is no online ordering for hair follicle tests. To arrange testing, call (877) 731-6362 to discuss your needs and receive guidance on scheduling a collection.
Pricing varies depending on the testing panel and detection window. Call for a quote.
Common Questions
Hair follicle testing typically detects drug use up to 90 days prior to collection by analyzing 1.5 inches of hair closest to the scalp.
Hair follicle testing is less sensitive to very recent drug use because it takes 5 to 7 days for drugs to appear in hair above the scalp.
No, passive exposure generally does not result in a positive hair follicle test since drugs must enter the bloodstream to be deposited in hair.
No, DOT-regulated safety-sensitive testing requires federally certified urine testing under 49 CFR Part 40. Hair testing is used for non-DOT roles.
A small hair sample is cut close to the scalp, usually from the crown area, to provide approximately 1.5 inches of hair for analysis.
All non-negative hair follicle test results are reviewed by a certified Medical Review Officer to confirm accuracy and rule out medical explanations.
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.