Hair Follicle Drug Testing I Top 15 Frequently Asked Questions
Accredited Drug Testing provides professional hair follicle drug testing services nationwide.
1) What is a hair drug test?
A hair drug test detects patterns of drug use over time by analyzing a small sample of hair, providing a detection window of up to 90 days or more for various substances.
2) How far back does a hair test detect drugs?
Hair drug tests typically detect use within the past 90 days. Body hair samples can show a longer detection period due to slower growth rates.
3) What substances are detected in a hair test?
Most panels include cocaine, marijuana (THC), opiates, amphetamines, methamphetamines, and PCP. Expanded panels can test for benzodiazepines, barbiturates, and prescription opioids.
4) How much hair is collected for testing?
Collectors typically cut about 100-120 strands (the size of a pencil eraser) close to the scalp. When head hair isn’t available, body hair may be used as an alternative.
5) How long should my hair be for testing?
Ideally, at least 1.5 inches of hair is needed to cover a 90-day history. Shorter samples can still be tested but will represent a shorter timeframe.
6) Does hair dye or bleach affect results?
Normal hair treatments like coloring or shampooing typically do not affect results. Labs wash samples before testing to remove surface contamination.
7) How soon after use can drugs be detected in hair?
Drugs appear in hair about 5-7 days after use as the hair grows out of the scalp. Hair testing is not used for recent drug use (less than 3 days).
8) Is hair testing DOT-approved?
No. The U.S. Department of Transportation (DOT) currently requires urine specimens for regulated testing. Hair tests are often used for non-DOT employment programs.
9) How long do hair drug test results take?
Negative results are usually available within 2-3 business days. Positive or non-negative results requiring confirmation may take longer for review by an MRO.
10) Can secondhand exposure cause a positive?
It’s very unlikely. Laboratories perform extensive washing and detect specific drug metabolites that confirm ingestion, not environmental exposure.
11) Can hair drug tests detect alcohol?
Standard panels do not test for alcohol, but a specialized EtG hair alcohol test can detect chronic alcohol use for up to 90 days.
12) Are hair drug tests court-admissible?
Yes. Certified labs follow strict chain-of-custody procedures making results legally defensible for court, probation, or child custody cases.
13) Can I refuse a hair drug test?
Refusal policies depend on the employer, court, or agency. Refusing a required test may have the same consequences as a positive result.
14) What happens if I shave my head?
If head hair is unavailable, collectors may use body hair. This can extend the detection window and still provide reliable results.
15) How do I schedule a hair drug test near me?
Call (800) 221-4291 or order online through Accredited Drug Testing for fast, confidential, and convenient appointments nationwide.
Order Hair Drug Test