What will a hair follicle test show
What Will a Hair Follicle Test Show for Accurate Drug Detection
What will a hair follicle test show? Hair follicle drug tests detect drug use over a 90-day window by analyzing hair samples for specific substances. They reveal chronic drug use rather than one-time exposure. AMH Nationwide routes collections through five national labs with certified Medical Review Officers. Call (877) 731-6362.
What will a hair follicle test show about drug use?
A hair follicle test will show evidence of drug use typically within the past 90 days by detecting metabolites deposited in the hair shaft. This test identifies chronic or repeated drug use rather than recent one-time use. It is commonly used by employers, courts, and probation agencies to verify abstinence or detect long-term patterns.
What drugs do hair follicle drug tests show?
Hair follicle drug tests can show a range of substances, including but not limited to:
The test analyzes hair samples for drug metabolites bound within the hair structure, providing a reliable record of use over several months.
How is a hair follicle drug test performed?
A small sample of hair, usually 1.5 inches from the scalp, is collected at an authorized collection site. AMH Nationwide directs clients to one of five national lab networks: Quest Diagnostics, LabCorp, Omega Labs, United States Drug Testing Labs, and ExperTox.
The sample is sent to the lab for analysis. Every non-negative result is reviewed by a certified Medical Review Officer (MRO) to ensure accuracy and interpret findings.
What is the detection window for a hair follicle drug test?
Hair follicle drug tests typically detect drug use within approximately 90 days prior to collection. This is because drugs are incorporated into hair as it grows, roughly 0.5 inches per month. The standard sample length of 1.5 inches represents about three months of history.
This test does not detect very recent drug use, such as within the past 7 days, due to the time required for hair growth.
Need a Hair Follicle Drug Test?
AMH Nationwide facilitates hair follicle drug testing through five national lab networks with certified Medical Review Officers reviewing all non-negative results. Contact us to schedule your collection or for more information. Call (877) 731-6362.
What can a hair follicle test not show?
A hair follicle test cannot reliably detect drug use within the last week because the hair containing the drug metabolites has not yet grown above the scalp.
It may not detect very light or one-time drug use if the metabolites fall below the lab’s cutoff levels.
Environmental contamination or passive exposure usually does not produce a positive result because the test detects metabolites inside the hair shaft, not external residues.
Who orders hair follicle drug tests and why?
Employers, courts, and probation agencies often order hair follicle drug tests to assess long-term drug use patterns for safety-sensitive roles or compliance monitoring.
Hair testing is preferred when a longer detection window is needed compared to urine or saliva tests, or when DOT-regulated testing does not apply since DOT requires federally certified urine protocols.
Common Questions
Hair follicle tests are more effective at detecting repeated or chronic drug use rather than single one-time use. One-time use may not produce enough metabolites in hair to trigger a positive result.
Hair follicle tests detect drug use starting approximately 7-10 days after use, reflecting the time it takes for hair containing metabolites to grow above the scalp. The detection window extends up to 90 days.
Hair color can slightly influence drug metabolite incorporation, but accredited labs account for this during analysis. Hair follicle tests remain reliable across hair colors.
All non-negative hair follicle test results are reviewed by a certified Medical Review Officer who verifies the findings and rules out legitimate medical explanations before confirming a positive result.
Hair treatments like bleaching or dyeing may reduce drug metabolite concentrations but generally do not eliminate them. Labs are trained to detect tampering or adulteration.
No, DOT-regulated testing requires urine testing under federally certified protocols. Hair follicle testing is used for non-DOT roles or additional screening purposes.
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.