Information On Hair Follicle Drug Testing

This is a comprehensive list of the most frequently asked questions about hair follicle drug testing. If after reading this, you have any further questions please feel free to contact us and we'll do our best to answer them for you.

Do you have to pull the hair sample out?

No, the hair sample can be cut with a pair of scissors. The closer you can get to the scalp, the more recent the test results will be. It is recommended that you cut the hair as close to the scalp as possible.

How much hair is needed for hair follicle drug testing?

For best results collect, approximately 50-80 strands of hair. This may seem like a lot, but when bunched together it would be approximately the diameter of a very small straw.

How long does the hair have to be?

Hair grows at approximately 0.5" (1.25 cm) per month +/- 10%. So to screen for a 3-month period, you would need to collect 1.5" (4 cm) of hair.

Can I collect a longer sample to screen for a longer period of time?

No, the lab only tests the first 1.5" (4 cm) of hair and will trim the sample accordingly. That is why it is imperative to orient the sample in the collection container with the root end of the hair in the correct place. If the sample is reversed, then the most recent drug use will not be present if the hair sample requires trimming.

How do the drugs get into the hair?

When a substance is used it enters the bloodstream. The hair follicle that is growing inside of the scalp absorbs these substances and stores them on the molecular level in that section of the hair. It takes 4-5 days for the hair to grow out of the scalp, so any drug ingested in the past few days may not show up on the test.

What if there is no hair on the person's head?

You can use body hair to screen for drug use. But because body hair grows at a slower rate, the test can detect substances used up to one year from the day the sample is taken. Do not mix body and head hair together as they will skew the results.

Can hair absorb THC from marijuana smoke in the air and cause a false positive?

No, the lab screens for the parent and the metabolite (bi-product) of the drug. When the drug is consumed or ingested, the body produces a metabolite which is different than the drug itself. The test will be positive only if this metabolite is present, which will rule out environmental absorption.  However, small quantities of inhaled, second-hand smoke may be detectable.

Can over-the-counter drugs affect the results of hair follicle drug testing?

It is possible that the Enzyme Immunoassay Antibodies (EIA) that are used to perform the initial screening of the hair could be affected by OTC drugs and medications. That's why every positive result found is verified using state of the art GC/MS (Gas Chromatography / Mass Spectrometry) equipment which verifies and confirms all positives yielding a 99.9% accuracy rate.

Does the colour of the hair matter?

No, it has been proven and accepted in the courts that hair colour is not related to the accuracy of the test.

Do hair treatments affect the accuracy of the test?

Common treatments i.e. Shampoos, gels, mousses etc., do not significantly affect the test. Neither do mild colourings or perms. If the hair has been repeatedly bleached or chemically treated and this has resulted in damage to the point of the hair breaking (damage to the cortex), then the levels of the drugs found will be lowered.

Can the test be fooled by detox shampoos or gels?

Not at all. The GC/MS test analyzes the molecules inside the hair - no topical solution can fool it. Of the three tests, hair analysis is the hardest one to cheat, because it is cheat-proof.

How long does it take to get the hair follicle drug testing results?

Once the sample has been received by the lab, the results are available within 1-2 business days. You will be notified by email when the test is complete. Then you simply log onto the secure website to view the results.