Hair Testing

NZDDA offer two options when it comes to hair testing.

The first is an evidential hair testing service which can provide a history of drug or alcohol use over a period of months making it ideal for court cases involving custody and care issues. Currently NZDDA use an american based laboratory for it's evidential hair testing and results take approximately 2 weeks but we are looking forward to being able to provide a New Zealand Based service in the near future.

Secondly we offer a take home DIY kit which can be used by parents or others to identify drug use. All the information on how to take the sample is provided in the kit along with postage paid evelopes and your unique identifier which you use to log on to a website and get your results in the privacy of your own home one or two weeks after submitting the sample.

About Hair Testing 

Hair testing is the most accurate and effective method of finding users of drugs of abuse. Using a small sample of hair cut at the scalp, hair analysis evaluates the amount of drug metabolites embedded inside the hair shaft.

When compared to the more traditional forms of testing, i.e. urine testing, hair samples can detect a longer period of drug use. With urine, most drugs are undetectable if urinalysis is done more than 3-6 days after use, with the exception of cannabis, which may be detected for a slightly longer period of time. After the 3-6 day period, a urine donor will test negative and slip through the urine screening process. With hair samples, the only time limitation for detecting drug usage is imposed by the length of the donor’s hair. Each 15mm of head hair provides a 30-day history of drug use. The standard for the industry is to test 45mm, which provides a 90-day history of the donor’s drug use. If no head hair is available, body hair can be used.

Bleaches, shampoos and external contaminants (i.e. cannabis smoke) have no known impact on test results. Collection of evidential hair samples can be done at any of our NZDDA offices around the country.

Q&A on Hair Testing

1. What is Hair Drug Testing?
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 measures the drug molecules embedded inside the hairshaft, eliminating external contamination as a source of a positive test result. Hair testing results cannot be altered with shampoos or other external chemicals.  

2. What drugs are included in a standard Hair Drug Test?
Cocaine, cannabis, opiates (Codeine, Morphine & 6-monoacteyl morphine), methamphetamine, (Meth/amphetamine & Ecstasy), and phencyclidine (PCP).

3. What time period does a standard test cover?
A standard test covers a period of approximately 90 days. The hair sample is cut as close to the scalp as possible and the most recent 45mm are tested.

4. Does hair color affect results?
Hair color is determined by the amount of melanin in the hair. It has been shown experimentally, through actual hair samples, as well as determined in court that hair color has NO basis in fact.

5. How fast does head hair grow?
Studies indicate that head hair grows on the average approximately 15mm per month. This growth rate varies slightly (estimated at ± 2 mm per month), consequently there is some (± 1 week) time variation possible.

6. How much hair is needed?
A standard test with GC/MS confirmation requires 60+ milligrams of hair or approximately 90 to 120 strands. The thickness of different types of head hair (thick coarse vs. thinning fine) is the reason for this variation.