Hair testing FAQs

Hair testing for drugs of abuse is the only drug testing method available that provides up to a 90-day drug use history. When compared with urine testing, hair testing tends to provide a greater number of positives due to its longer detection window. Hair testing requires a small sample of hair that is collected under direct supervision without any invasion of privacy. It is an excellent option for pre-employment and random drug testing programs. 

Quest Diagnostics tests for amphetamines (amphetamine, methamphetamine, MDMA and MDA), opiates (codeine, morphine and 6-monoacetylmorphine) or “expanded” opiates (which includes semi-synthetic opiates), cocaine (and cocaine metabolites), marijuana metabolite (THC carboxylic acid metabolite), and PCP (phencyclidine).

Quest Diagnostics standard screen usually requires a cosmetically undetectable lock of hair preferably snipped from the back of the head, just below the crown. In general, the amount needed equates to a single row of hairs approximately one (1) centimeter wide.

We have not found any adulterants that can beat a hair drug test at this time. Moreover, the risk is minimized because every hair collection is observed.

Calling a hair test a hair follicle test is a common misnomer. The hair follicle is actually the pocket, below the scalp, from which the hair strand grows. During a hair drug test collection, the hair is cut as close to the scalp as possible, so only the strands of hair above the scalp is tested and not the actual hair follicle.  True hair follicle testing requires the hair to be “plucked” rather than cut which can lead to extreme donor discomfort.  

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