Question: What is the difference between hair drug testing and hair follicle drug testing?
Calling a hair test a hair follicle test is a common misnomer. We looked to Dr. Barry Sample, Senior Director of Science & Technology, Quest Diagnostics, a scientific expert in our Lenexa, Kansas hair drug testing laboratory, to better understand hair testing terminology and the hair testing collection process.
What is a hair follicle?
The hair follicle is actually the pocket, below the scalp, from which the hair strand grows. An actual “hair follicle” test may be quite painful for the donor as it would likely involve plucking the hair from the scalp. Consequently, during a hair collection, the hair is cut as close to the scalp as possible, so only the strands of hair above the scalp are tested and not the actual hair follicle.
During a hair testing collection, the collector cuts approximately 100-120 strands of hair from the crown of the donor’s head. When a sample is taken from the crown, a sufficient amount of hair is available for testing without causing cosmetic affects to the donor.
Once collected, the hair strands are aligned and placed into the foil packet provided with each hair collection kit. The collector aligns the root ends of the hairs with the slanted end of the foil and then folds the foil in half to secure the hair. The foil and hair are then inserted into the hair testing specimen envelope. Upon receipt of the hair specimen, the lab measures and cuts 3.9 centimeters of hair from the area closest to the root-end and tests the hair specimen for drugs of abuse.
Why choose hair testing
Hair testing is the only drug testing method available that provides a detection window of up to 90 days, an effective way to evaluate long-term patterns of repetitive use. Collections for hair tests are observed, meaning a collection can only be performed at a collection site, and performed by a collector, therefore reducing the likelihood of tampering or adulteration by a donor.
Watch an on-demand recording of our Back to basics: Hair drug testing webinar.
Updated April 27, 2021