Hair Drug Testing FAQ

Q: How long will it take to receive the results?

Hair Testing results are generally available 2 business days after the hair sample has been received by the laboratory.

A: How far back will Hair Testing detect drug use?

Hair Testing for drugs generally uses 1-1/2 inches of hair that represents about 3 months of growth. It is generally accepted that in order to test positive, the drug in question must have been used 3 times or more within the window of the Hair Test. After a drug is used, it takes about 7 to 10 days for the hair containing the drug to grow out of the scalp enough to be cut. Consequently, the Hair Test will not include drugs used in the week prior to the test.

A: Does hair color affect the results of a Hair Test for drugs?

No, Hair color is a determining factor.

A: What drugs can be detected using Hair Testing?

Hair testing is performed for the following five controlled substances:
Marijuana, Cocaine,PCP/Phencyclidine, Amphetamines and Opiates

A: When Hair Testing for drugs, how many hairs are required for laboratory testing?

Approximately 60 – 100 strand cut from the scalp line at the crown (or when bundled, about the diameter of a pencil lead).

A: How will I read the results of the hair test?

A positive or negative result will be given for each drug class.

A: Can Hair Testing be run on people with little or no hair?

Hair can be collected from several head locations and combined to obtain the required amount of hair. If the head hair is too short, body hair can be used as a substitute.
NOTE: DO NOT mix head and body hair to submit for sample.

A: What is the shortest time period that can be accurately evaluated with a Hair Test?

The minimum time period is approximately one month (0.5 inch).

A: Can I use a hair from a hairbrush to perform the Hair Test?

No, we do not recommend taking a hair sample from a hairbrush or any other source (e.g. pillow, clothing) as the drug test sample may be contaminated and there is no guarantee that the hair is from the person being hair tested. It also would invalidate the legality of the test results, as proper chain of custody cannot be established.

A: How effective is Hair Testing for detecting drug use?

In comparison drug test studies with urinalysis, hair drug testing has uncovered significantly more drug use. In two independent studies, hair drug testing uncovered 5 to 10 times as many drug users as urinalysis did.