How long does a hair follicle test go back
How Long Does a Hair Follicle Test Go Back? Understanding the Detection Period
How long does a hair follicle test go back? Hair follicle drug tests typically detect drug use within the past 90 days. This test analyzes drug metabolites embedded in hair shafts, providing a longer detection window than urine or saliva tests. Hair grows about half an inch per month, enabling a 1.5-inch sample to represent roughly three months of history. Call (877) 731-6362 for testing information.
How long does a hair follicle test go back for drugs?
A hair follicle test generally detects drug use within the last 90 days. This is because hair grows approximately 0.5 inches per month, and standard testing analyzes about 1.5 inches of hair closest to the scalp.
Drugs and their metabolites enter the hair follicle through the bloodstream and become embedded in the hair shaft as it grows. This allows the test to reveal drug exposure over an extended period, much longer than urine or saliva tests.
Hair follicle testing is preferred when a longer detection window is necessary, such as for employment, legal, or probation requirements. Call (877) 731-6362 to arrange testing through AMH Nationwide’s national lab network.
How long does the hair drug test go back and what substances can it detect?
The hair drug test covers a detection period of up to 90 days. It can detect a range of substances depending on the panel ordered. Common drugs identified include:
Detection depends on the drug’s ability to incorporate into the hair shaft and the sensitivity of the lab’s assay. For specific panel options and detection windows, call (877) 731-6362.
How does the hair follicle drug test work and what is the collection process?
The hair follicle drug test works by analyzing a small sample of hair, usually about 1.5 inches in length taken from the scalp. This sample represents approximately 90 days of hair growth and drug exposure.
AMH Nationwide directs customers to one of five national laboratory networks for collection: Quest Diagnostics, LabCorp, Omega Labs, United States Drug Testing Labs, and ExperTox. There is no online ordering; all testing requires a lab order and scheduled collection.
After collection, the sample is sent to the lab for analysis. Any non-negative results are reviewed by a certified Medical Review Officer (MRO) as part of standard protocol to ensure accuracy and proper interpretation.
DOT-regulated safety-sensitive testing uses federally certified urine protocols; hair testing is for non-DOT roles. Contact AMH Nationwide at (877) 731-6362 for test coordination.
How long does drugs stay in hair follicle and can recent drug use be detected?
Drugs typically remain detectable in hair follicles for up to 90 days after use. However, very recent drug use within the past 5-7 days may not be detected because it takes time for hair containing drug metabolites to grow above the scalp surface.
Hair testing cannot detect drug use within hours or a few days prior to collection. For short detection windows, urine or saliva tests are more appropriate.
Understanding this timing helps employers and individuals select the appropriate test type. Call (877) 731-6362 to discuss testing options.
Schedule Your Hair Follicle Drug Test Today
To arrange hair follicle drug testing with AMH Nationwide, call (877) 731-6362. We coordinate testing through five national lab networks and ensure certified MRO review of results.
Who typically orders hair follicle drug testing and why?
Hair follicle drug tests are commonly ordered by employers, legal authorities, probation officers, and individuals seeking a longer-term drug use history.
Employers use hair testing to verify abstinence over months, especially in safety-sensitive or regulatory environments. Courts and probation departments rely on hair testing to monitor compliance over extended periods.
Individuals may request hair testing for personal reasons or to meet specific requirements. AMH Nationwide supports all orderers by providing lab orders and directing to nationwide collection sites.
For test ordering details and collection site locations, call (877) 731-6362.
How reliable is the hair follicle drug test compared to other methods?
Hair follicle drug testing is highly reliable for detecting drug use over the previous 90 days. It is less susceptible to adulteration or substitution than urine tests.
The test is conducted through accredited labs including Quest Diagnostics, LabCorp, Omega Labs, United States Drug Testing Labs, and ExperTox. All non-negative results are confirmed and reviewed by certified Medical Review Officers.
While hair testing cannot detect very recent use, its long detection window and resistance to tampering make it a preferred choice for many employers and legal entities.
Contact AMH Nationwide at (877) 731-6362 to schedule hair follicle testing through trusted national labs.
Common Questions
No, the standard hair follicle test analyzes about 1.5 inches of hair, representing roughly 90 days of growth. Drug use beyond that period is generally not detected.
A small sample of hair, about 1.5 inches long, is cut close to the scalp, usually from the crown area. This sample is sent to an accredited lab for analysis.
Hair color and type can have minor effects on drug incorporation, but accredited labs use validated methods to ensure accurate results regardless of hair characteristics.
Passive exposure is unlikely to produce a positive hair follicle test because the analysis detects drug metabolites incorporated inside the hair shaft, not surface contamination.
No, DOT-regulated safety-sensitive testing requires federally certified urine testing under 49 CFR Part 40. Hair follicle tests are used for non-DOT roles.
Results typically take several days to a week, depending on the lab. All non-negative results undergo review by a certified Medical Review Officer before reporting. Call (877) 731-6362 for timing details.
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.