Hair testing analyzes a hair sample for parent drugs and their metabolites.  Since hair growth is fed by the bloodstream, the ingestion of drugs of abuse is revealed by analyzing a small sample of hair. Our testing method mostly measures the drug molecules embedded inside the hair shaft, eliminating most external contamination as a source of a positive test result. Hair testing results are not typically altered with shampoos or other external chemicals enough to change the test result from positive to negative or vise versa.

For head hair, the standard window of detection is 90 days which uses 1.5 inches of hair. However, longer and shorter time-frames are possible. Each ½ inch of head hair provides about a 30-day history of drug use. Body hair samples cover up to a 1 year time-frame for results but should only be used if head hair is not available since body hair has a few disadvantages compared to head hair. It takes 7 to 10 days before an ingested drug becomes part of a hair sample.

Compared to urine based testing: cocaine, methamphetamine, opiates and PCP are rapidly excreted and usually undetectable in about 72 hours after use.

In side-by-side comparison studies with urinalysis, hair drug testing has uncovered significantly more drug use. In two independent studies hair drug testing uncovered 4 to 8 times as many drug users as urinalysis. Keep in mind that this test is designed to catch a moderate to heavy user, not a one or two time user.  The longer testing time-frame accounts for the higher “positive” results.

A standard test with GC/MS, GC/MS/MS or LC/MS/MS confirmation requires 60+ milligrams of hair or approximately 90 to 120 strands.  Hair is cut as close as possible to the scalp.

The potential for substances such as over-the-counter medications to cause a false positive screening result does not exist because of the built in back up measures we use. To eliminate the possibility of reporting a false-positive due to cross-reactivity, all positive results are tested again by GC/MS, GC/MS/MS or LC/MS/MS. We also use a Medical Review officer (MRO) to rule out a positive result due to a valid prescription medication at no additional fee.

The cut-off levels are generally standard and accepted industry-wide. Click the CutOff Levels page for details.

Test reports are retained for a period of two years or as mandated by law.

The hair not used from the time period being tested (i.e. three months equals about 1.5 inches) is stored in the chain-of-custody sample acquisition pouch. Hair is stored for a one year period at the Lab for positive results and only a couple of days for negative results. Hair over 1 1/2 inches is cut off and discarded, at the lab, before testing begins.

Hair testing mostly analyzes the drugs inside the hair shaft but external contaminants/chemicals can have an effect. Bleaches, shampoos and external contaminants can alter test results. In my opinion, based on conversations with toxicologists and scientific studies, external contaminants may alter the drug levels measured by 20% to 50% (or more).  Theoretically, because the majority of “positive ” results are more than double the cutoff limit, that percentage change would only change the outcome if the result would have been borderline negative without the contaminant.  If hair products are a concern, doing a finger nail test is a great alternative.

It has been shown experimentally, through actual hair samples, as well as determined in court that hair color can  impact some results. Studies have shown that dark hair can bind certain drug metabolites tighter than light hair which can impact drug level results. Again, using finger nails is a good alternative.

The minimum time period is approximately 1 month, about 1/2 inch of hair. The minimum sample is based on weight not strands of hair so a larger area of hair will be cut for short hair which can leave a bald spot. If you are worried about a bald spot or too short of a testing time-frame, a finger nail or body hair sample can be used instead of head hair.

The possibility of an external contaminate for marijuana analysis (i.e. marijuana smoke) affecting the test does not exist.  The hair is only tested for the for the marijuana metabolite (THC-COOH). This metabolite is only produced by the body, not an environmental contaminant like smoke. (The ChildGuard hair test for children is designed to detect drugs by exposure to smoke and other external environmental factors because it tests for the parent drug and the metabolite.)

Hair can be collected from several head locations, and combined, to obtain the required amount of hair. In addition, body hair may be used as a substitute to head hair. In the rare case where no hair is collectible, urine, saliva and nail testing may be utilized. Only nail testing covers a similar time frame to hair testing.

In general the answer is yes.  Body hair can be used to test for the five panel “standard” drug test up to the 17 panel test. Body hair growth rates can be slower and most of it is in the “dormant” stage for 6 to 12+ months so it cannot be utilized to determine an accurate time-frame of drug use. Most body hair is replaced within approximately one year, meaning a test done with body hair will theoretically report drug usage for up to a one year time-frame.  The results sheet will not specify a 1 year time frame because different parts of the body grow hair at different rates. I believe a finger nail test is a much better substitute if the persons nails are long enough.  Clipping about the thickness of a quarter is needed from all 10 fingers to provide a sufficient sample.

Yes, but the test will be reported as having an “anonymous” donor. We cannot attribute the sample to any specific person and we cannot determine the time frame of the test, so the test result is not legally defensible. The test will only report that the sample submitted had the reported drug metabolite components indicated.