Hair Drug Testing

Hair drugs of abuse testing offers up to a 90-day window for detection of drug use1 prior to the test date and a convenient collection process that can be performed almost anywhere.

Specimen Collection

The collector obtains a 100-milligram sample of hair (90 to 120 strands) cut at the scalp. The collector secures the hair sample in foil and completes chain of custody documentation in preparation for shipment to the testing laboratory. Since hair samples are obtained in full view of the collector, the process minimizes the likelihood of sample adulteration or specimen substitution. Labcorp offers hair specimen collections in many of our specimen collection sites located throughout the United States. Our extensive network offers your employees convenient access to a Labcorp collection site.

Testing Process

Labcorp offers initial screening tests performed by enzyme-linked immunosorbent assay (ELISA) with confirmation of presumptive positive screens by gas chromatography/tandem mass spectrometry (GC/MS-MS) or liquid chromatography/tandem mass spectrometry (LC/MS-MS). Results for specimens that screen negative for all drugs are generally available within 48 to 72 hours after specimens are received at the laboratory. Results for confirmation testing of presumptive positive screens are usually available within an additional 72 hours.

Drugs Detected

  • Amphetamine/methamphetamine/ecstasy
  • Marijuana metabolite
  • Cocaine and metabolites
  • Opiates (codeine, morphine, 6-acetylmorphine)
  • Phencyclidine (PCP)

To set up a hair drug testing program, contact Labcorp sales.

Hair Drug Testing FAQ

  • How does the drug detection window for hair compare to urine and oral fluid?

    Drug detection times vary depending on the dose, sensitivity of the testing method used, preparation and route of administration, duration of use (acute or chronic), the matrix that is analyzed, the molecule or metabolite that is looked for, the pH and concentration of the matrix (urine, oral fluid), and variations in metabolic and renal clearance.2 In general, the detection time is longest in hair, followed by urine and oral fluid.2 Drugs in hair may be detectable for approximately 90 days, whereas drugs in urine are generally detectable for one to seven days or longer in chronic users and in oral fluid from five to 48 hours.2

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  • What is hair drug testing?

    Drug and drug metabolite(s) are incorporated into the hair matrix from the bloodstream following drug use. Hair drug testing detects drugs that are embedded in the hair.1

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  1. Proposed revisions to Mandatory Guidelines for Federal Workplace Drug Testing Programs. Federal Register. April 11, 1988; 53:11970; amended June 9, 1994; 59:29908; September 30, 1997; 62:51118; April 13, 2004; 69:19675-19676,19679,19697- 19698.
  2. Verstraete, AG. Detection times of drugs of abuse in blood, urine, and oral fluid. Ther Drug Monit. 2004;28(2):200-205.