How long does a hair follicle drug test
How Long Does a Hair Follicle Drug Test Detect Drugs for Reliable Results
How long does a hair follicle drug test detect drugs depends on hair length and substance but typically covers up to 90 days of drug use. This test analyzes hair samples collected at authorized sites and reviewed by certified Medical Review Officers. Call (877) 731-6362 to schedule testing or get more information.
How long does a hair follicle drug test detect drugs?
A hair follicle drug test can detect drug use for up to 90 days prior to the test date. This is because drugs and their metabolites are deposited in the hair shaft from the bloodstream as hair grows. Typically, a 1.5-inch hair sample represents approximately three months of drug history.
The test is not effective for detecting very recent drug use within the past 5 to 7 days, as hair needs time to grow above the scalp to be sampled.
How is a hair follicle drug test performed?
The hair follicle drug test involves collecting a small sample of hair, usually about 100 strands, from the crown of the head or another body area if head hair is unavailable. The sample is then sent to one of five national lab networks: Quest Diagnostics, LabCorp, Omega Labs, United States Drug Testing Labs, or ExperTox.
AMH Nationwide provides the lab order and directs the requester to a local collection site. There is no online ordering for this test. All non-negative results undergo review by a certified Medical Review Officer as part of standard processing.
Who typically orders hair follicle drug testing?
Employers frequently use hair follicle drug tests for pre-employment screening or random employee testing due to the extended detection window and resistance to tampering.
Courts, probation officers, and legal agencies may also require hair follicle tests to monitor drug use over a longer period.
Individuals may request hair follicle testing for personal reasons, such as verifying abstinence or for custody cases.
How long does a hair follicle test for drugs detect different substances?
Hair follicle testing generally detects most common drugs for up to 90 days. Detection windows vary slightly by drug type but are generally consistent due to hair growth rates.
| Drug Type | Typical Detection Window |
|---|---|
| Marijuana (THC) | Up to 90 days |
| Cocaine | Up to 90 days |
| Opiates (Heroin, Morphine) | Up to 90 days |
| Amphetamines | Up to 90 days |
| Phencyclidine (PCP) | Up to 90 days |
Schedule Your Hair Follicle Drug Test Today
Contact AMH Nationwide for lab testing through one of our five national lab networks. Call (877) 731-6362 to arrange testing or to speak with a testing coordinator.
Can hair follicle drug tests detect one-time or passive drug exposure?
Hair follicle tests detect drug use reflected in incorporated metabolites over weeks to months. One-time or very recent drug use may not be detected if hair has not yet grown out.
Passive exposure to drugs is unlikely to produce a positive result because the test detects metabolites inside the hair shaft, not external contamination. Labs follow strict washing protocols to remove external substances.
Are hair follicle drug tests compliant with DOT regulations?
Hair follicle drug tests are not used for Department of Transportation (DOT) safety-sensitive testing. DOT-regulated testing requires federally certified urine protocols under 49 CFR Part 40.
Hair testing is reserved for non-DOT roles or as additional testing but must follow strict chain-of-custody and lab certification standards.
Common Questions
Hair follicle tests generally cannot detect drug use within the first 5 to 7 days after consumption because hair needs time to grow above the scalp. Detection begins once the hair containing drug metabolites emerges from the scalp.
Hair color and type can influence drug metabolite incorporation slightly, but accredited labs account for these variables. The test remains reliable across hair types.
Results typically return within 3 to 5 business days after the lab receives the hair sample. Non-negative screens undergo additional review by a certified Medical Review Officer.
Chemical treatments may reduce drug metabolite levels in hair but do not guarantee a negative result. Labs are experienced in interpreting such samples.
Hair follicle tests provide a longer detection window, up to 90 days, compared to urine tests which detect recent use typically within days. Both have specific applications.
AMH Nationwide provides lab orders and directs you to a nearby collection site. Call (877) 731-6362 to schedule your hair follicle drug test or get more information.
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.