Hair has become a very effective tool for drug testing as it offers a wider window of detection for drug use. One test conducted with head hair can offer up to a 90 day history of drug use and is well suited to determine if donors have a pattern of abuse. Laboratories report nearly twice as many positives on hair drug tests as compared to urine drug tests. Many provide a valid argument that hair testing is more beneficial for pre-employment and random testing as it provides more information about long term consistent drug abuse as compared to other specimens that only offer a window of detection from hours up to ten days.
Is Hair Testing Reliable?
Hair growth is fed by the bloodstream, therefore drugs that are ingested are revealed by analyzing a small sample of hair. The laboratory’s testing method measures drug molecules that are embedded inside the hair shaft. This process eliminates external contamination and prevents any false positive test results. It also prevents the results from being altered with shampoos, coloring or any other external chemical agents. Some are afraid that donors may attempt to “beat” a hair test by coloring their hair, but it has been shown experimentally, through actual hair samples, as well as determined in court that hair color has no significant impact on results.
How much hair is needed?
A standard hair test performed with (GC/MS, GC/MS/MS or LC/MS/MS) confirmation will require approximately 60+mg of hair. Due to the varying thickness in donors’ hair strands you can expect anywhere from 90 to 120 strands of hair to be taken. The hair that is taken must be cut as close to the skin as possible to provide an accurate timeline. The sample is taken from multiple locations on the donor’s head to prevent leaving a noticeable “bald” spot.
How long does my hair have to be?
The length of a donor’s head hair must be at least 1/4 inch to be used as a sample for testing. Research has shown that head hair grows on an average of 1/2 in (1.3cm) per month and it takes about 7-10 days from the time of actual drug use until the exposed hair grows above the scalp. One test can sample up to a 90 day history or 1.5 in of head hair. If the donor’s head hair is shorter than 1/4 inch, then body hair may be used for testing purposes. Body hair growth patterns are different than head hair. Most body hair is replaced within approximately one year. This means a test done with body hair will be reported as drug usage during approximately a one year timeframe.
What drugs will my hair be tested for?
The most common drug test that is conducted is a five panel with expanded opiates.
5 Panel with Extended Opiates
- Marijuana (ThC)
- Cocaine (COC)
- Phencyclidine (PCP)
- Amphetamines – Methamphetamine (MDMA, MDA, Ecstasy)
- Opiates – Codeine, Morphine, Heroin, Metabolite, Hydrocodone(Vicodin, Lorcet, Lortab)
- Extended Opiates – Hydromorphone (Dilaudid), Hydromorphone (Percocet)
*All positive results are confirmed by GC/MS.