How long does a hair follicle go back
How Long Does a Hair Follicle Test Detect Drug Use for Effective Screening
How long does a hair follicle go back? Hair follicle drug tests typically detect drug use up to 90 days prior, depending on hair length and growth rate. This makes hair testing ideal for long-term substance use screening. AMH Nationwide uses five national lab networks for accurate testing. Call (877) 731-6362.
How long does a hair follicle go back in detecting drug use?
A hair follicle test can detect drug use for approximately 90 days prior to the test date. This detection window depends on the average hair growth rate of about half an inch per month and the length of the hair sample collected. Typically, a 1.5-inch hair sample is used to cover roughly three months of drug exposure.
Hair testing is preferred when an extended detection window is required, such as for pre-employment screening, probation monitoring, or legal cases.
How is a hair follicle drug test conducted?
Hair follicle testing involves collecting a small sample of hair, usually from the crown of the head. If head hair is unavailable, body hair may be used, though it can affect detection accuracy.
The sample is sent to one of five national lab networks: Quest Diagnostics, LabCorp, Omega Labs, United States Drug Testing Labs, or ExperTox. Each lab follows strict protocols, including review of all non-negative results by a certified Medical Review Officer.
Are there limitations to how long a hair follicle test can detect drug use?
Hair follicle tests do not detect very recent drug use within the past 7 days because drugs take time to incorporate into hair shafts as they grow.
Detection accuracy can be influenced by hair treatments like bleaching or dyeing, but labs have methods to account for these factors.
The detection window is limited to the amount of hair collected; longer detection periods require longer hair samples, which may not always be feasible.
How does hair follicle testing compare to urine or saliva testing in detection windows?
Hair follicle testing offers a significantly longer detection window compared to urine or saliva tests. Urine tests typically detect drug use within 1 to 7 days, while saliva tests detect use within hours to a few days.
Hair testing is not suitable for detecting very recent drug use but excels in identifying patterns of use over months.
| Test Type | Typical Detection Window |
|---|---|
| Hair Follicle Test | Up to 90 days |
| Urine Test | 1 to 7 days |
| Saliva Test | Hours to a few days |
Need a Reliable Hair Follicle Drug Test?
Contact AMH Nationwide to schedule a hair follicle drug test with nationwide collection and expert result review. Call (877) 731-6362.
Is hair follicle testing used for DOT-regulated drug screening?
Hair follicle testing is not accepted for DOT-regulated safety-sensitive drug testing. The Department of Transportation requires urine testing following the federally certified 49 CFR Part 40 urine protocol.
Hair tests are used for non-DOT roles where extended detection windows are important, such as certain employer or legal testing programs.
How can someone get a hair follicle drug test through AMH Nationwide?
AMH Nationwide provides the lab order and directs the requester to one of over 20,000 nationwide collection sites. There is no online ordering available.
The process includes sample collection, laboratory analysis by one of five certified labs, and review of results by a certified Medical Review Officer.
Pricing varies by panel and detection window; call (877) 731-6362 for a quote.
Common Questions
Hair follicle tests typically detect drug use up to 90 days prior, based on hair length collected. Longer detection requires longer hair samples, which may not be practical.
Hair color and type can slightly influence drug incorporation, but certified labs use methods to minimize these effects and ensure accurate results.
Yes, chemical treatments may reduce detectable drug levels, but labs account for this during analysis to maintain result integrity.
Hair follicle tests generally cannot detect drug use within the first 7 days because drugs need time to grow into the hair shaft.
Hair follicle testing can be more expensive due to longer detection windows and lab processing. Pricing varies by panel; call (877) 731-6362 for details.
Employers, courts, probation officers, and individuals seeking long-term drug use screening commonly order hair follicle tests.
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.