How long does a hair sample go back
How Long Does a Hair Sample Go Back for Drug Testing? Understand the Timeline
How long does a hair sample go back is a common question in drug testing. Hair samples typically provide a detection window of up to 90 days, revealing drug use over a longer period than urine or saliva tests. This makes hair testing valuable for employers, courts, and probation agencies. Call (877) 731-6362 to schedule or learn more.
How long does a hair sample go back for drug detection?
A hair sample generally goes back about 90 days for detecting drug use. This period depends on the length of the hair collected, as hair grows approximately 0.5 inches per month. Most drug tests analyze 1.5 inches of hair closest to the scalp, representing roughly three months of drug history.
Hair testing detects drug metabolites deposited in the hair shaft from the bloodstream. Because hair retains these metabolites, it provides a longer detection window than urine or oral fluid tests, which detect more recent use only.
What substances can be detected in a hair sample?
Hair drug testing can detect a wide range of substances, including:
– Amphetamines (including methamphetamine)
– Cocaine
– Marijuana (THC)
– Opiates (such as heroin, morphine, codeine)
– Phencyclidine (PCP)
– Synthetic opioids (fentanyl and analogs)
– Benzodiazepines (in some panels)
The exact substances tested depend on the test panel requested by the ordering party. AMH Nationwide routes samples through five national lab networks with extensive drug panels.
Which labs process hair samples for AMH Nationwide?
AMH Nationwide routes hair samples through five national lab networks: Quest Diagnostics, LabCorp, Omega Labs, United States Drug Testing Labs, and ExperTox. Each lab follows strict chain-of-custody and testing protocols to ensure accuracy and reliability.
All non-negative hair test results undergo review by a certified Medical Review Officer (MRO) before final reporting. This review helps confirm results and address any legitimate medical explanations for positive findings.
Who orders hair drug testing and why?
Hair drug testing is commonly ordered by employers for pre-employment screening and ongoing workforce monitoring. Courts and probation agencies also use hair testing to monitor compliance over longer periods.
Because hair testing provides a 90-day detection window, it is preferred when a longer-term drug use history is required rather than recent use only. Hair tests are not used for DOT-regulated safety-sensitive roles, which require federally certified urine testing protocols under 49 CFR Part 40.
Schedule Hair Drug Testing with AMH Nationwide
To arrange hair drug testing or get detailed information about detection windows and lab procedures, call (877) 731-6362. AMH Nationwide will direct you to a nearby collection site and coordinate testing through national labs.
How is a hair sample collected and processed?
Hair collection involves cutting a small sample from the scalp area, typically from the crown or back of the head. The sample length is usually 1.5 inches to represent approximately 90 days of growth.
AMH Nationwide directs the requester to a nearby collection site within its network. There is no online ordering; all testing requires a lab order and collection appointment. After collection, the sample is sent to a designated lab for analysis and MRO review.
How long does it take to get hair test results?
Hair test results typically take 5 to 7 business days after the lab receives the sample. This includes initial screening, confirmatory testing for non-negative results, and review by a Medical Review Officer.
The turnaround time can vary depending on the lab network and test panel complexity. Contact AMH Nationwide at (877) 731-6362 for expected timing based on your specific testing needs.
Common Questions
Standard hair drug tests analyze approximately 1.5 inches of hair, which corresponds to about 90 days. Longer hair samples can extend the detection window but are less common and may not be requested by employers or courts.
Hair testing detects drug metabolites incorporated into the hair from bloodstream exposure. Passive environmental exposure is unlikely to cause a positive result if standard collection and lab protocols are followed.
No. DOT-regulated drug testing requires urine samples collected under federally certified protocols (49 CFR Part 40). Hair testing is used for non-DOT roles requiring longer detection windows.
Hair testing can detect ethyl glucuronide (EtG), a biomarker for alcohol consumption, but this test is less common and requires specific panels. Standard hair drug tests focus on drugs of abuse rather than alcohol.
Hair testing detects drug use over 90 days, while urine testing typically detects recent use within a few days to a week. Hair testing is preferred when longer-term use history is required.
All non-negative hair test results are reviewed by a certified Medical Review Officer (MRO). The MRO evaluates the results and contacts the individual to verify any legitimate medical explanations before final reporting.
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.