How long will drugs show in a hair follicle test
How Long Will Drugs Show in a Hair Follicle Test for Reliable Results
How long will drugs show in a hair follicle test depends on the hair growth cycle, typically detecting drug use up to 90 days prior. Hair follicle tests provide a longer detection window than urine or saliva tests. AMH Nationwide processes all hair tests through five national lab networks with certified Medical Review Officer oversight. Call (877) 731-6362.
How long do drugs show in a hair follicle test?
Drugs typically show in a hair follicle test for up to 90 days after use. This period reflects the approximate length of hair growth tested, usually 1.5 inches from the scalp. Hair testing captures drug metabolites deposited in the hair shaft as it grows, providing a longer detection window compared to urine or saliva tests.
How does the hair follicle test detect drugs over this period?
The hair follicle test analyzes drug metabolites that enter the hair follicle from the bloodstream. As hair grows about half an inch per month, a 1.5-inch sample reflects roughly three months of drug exposure. Drugs are deposited in the hair cortex and remain stable, allowing detection of past drug use over an extended period.
What is the hair follicle drug testing process at AMH Nationwide?
AMH Nationwide directs test requesters to a nearby collection site from our network of over 20,000 nationwide. Hair samples are collected by trained professionals following strict chain-of-custody protocols. Samples are then routed to one of five national lab networks: Quest Diagnostics, LabCorp, Omega Labs, United States Drug Testing Labs, or ExperTox for analysis.
Non-negative results are reviewed by a certified Medical Review Officer to ensure accuracy and proper interpretation.
How does hair follicle testing compare to other drug tests in detection time?
Hair follicle testing offers the longest detection window among common drug tests, making it suitable for employer, court, or probation monitoring where extended drug use history is relevant.
| Test Type | Typical Detection Window |
|---|---|
| Urine Test | 1-7 days depending on drug |
| Saliva Test | 1-3 days |
| Hair Follicle Test | Up to 90 days |
Schedule a Hair Follicle Drug Test with AMH Nationwide
To arrange hair follicle drug testing, call (877) 731-6362. AMH Nationwide will direct you to authorized collection sites and ensure processing through certified national labs with expert result review.
Can a hair follicle test detect a single drug use or passive exposure?
Hair follicle tests are more effective at detecting repeated or chronic drug use rather than a single use. Passive exposure typically does not result in a positive hair test due to the low level of drug incorporation. The test’s sensitivity and specificity are enhanced by laboratory analysis and Medical Review Officer oversight.
Is hair follicle testing used for DOT-regulated safety-sensitive positions?
Hair follicle testing is not accepted for DOT-regulated safety-sensitive testing. DOT requires federally certified urine testing under 49 CFR Part 40. Hair follicle tests are used primarily for non-DOT roles where a longer detection window is needed.
Common Questions
A hair follicle test can detect drug use for up to 90 days after consumption, depending on hair length collected. This extended window is due to drug metabolites being deposited and retained in the hair shaft as it grows.
Hair follicle tests are more effective at identifying repeated or chronic drug use. One-time use may not always result in detectable levels, but it depends on the drug and timing relative to hair growth.
Passive exposure rarely causes a positive hair follicle test because drug incorporation into hair requires bloodstream exposure at detectable levels.
A small hair sample, typically 1.5 inches long and about 100 strands, is cut close to the scalp by a trained collector at an authorized site following chain-of-custody procedures.
All non-negative hair follicle test results are reviewed by a certified Medical Review Officer to confirm findings and assess any legitimate medical explanations.
No, hair follicle testing is not accepted for DOT safety-sensitive testing. DOT requires urine testing under federally certified protocols. Hair testing is used for non-DOT drug 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.