Frequently asked questions drug hair testing

What is the hair drug testing?

Hair growth is fed by the bloodstream, this makes possible the determination of drugs of abuse or their metabolites by analysis of hair samples.

hair-growth Hair growth is cyclical called hair cycle. Each follicle has its own cycle, independent of which there are around. Studies indicate that hair grows about 1 cm per month. The different phases of hair growth make hair the most recommended sample for this type of test.

What is required for analysis?

  • 60-100 mg of hair at least.
  • Indicate end corresponding to the base of the hair.
  • Specify centimeters and segments to analyze.
  • Detail drug (s) to be determined.
  • Complete documentation provided.

What drug is able to determine this test?

Currently detect cocaine, cannabis and MDMA (ectasy). 

What is the approximate time of detection in hair compared with urine and / or saliva?

 Periods of drug detection in a biological sample vary depending, among other factors, drugs, levels of use, frequency of use, purity of the drug sensitivity of the analytical method used, physiology of the individual and biological sample used for detection.

Normally the detection time is longer for the hair samples followed by urine and saliva. The minimum time for detection is 7 to 10 days after consumption as it is the period required for hair follicle out to the base of the scalp.

How fast your hair grows?

As noted hair grows about 1 cm per month, especially in the occipital region of the head. This is a consensus statistic because hair growth varies according to the characteristics of the person, age, sex, race, etc.Therefore depending on the length of hair of the person and the period to be detected can estimate the approximate length of test sample. 

What advantages does this type of sample?

  • Analyzes different and longer periods of consumption. The detection period for hair is limited only by the length of the hair sample.
  • Take sample with a noninvasive method.
  • Difficulty of adulteration.

How much hair is needed?

For determination requires between 60 and 100 mg of hair minimum. This corresponds graphically to a lock of hair as thick as a pencil.

How can you make the analytical laboratory?

Depending on the intended purpose, the analysis can be performed:

  • Analyzing the substance in all the cm indicated by the client in the submitted sample (Analysis 1 only).

* Example: hair length is 6 cm and are asked to analyze the first two cm that would belong to 2 months of hair growth.

  • Fractionating the sample in 3 fragments for each drug to analyze. In this case the customer must indicate the length to the laboratory will analyze each fragment from the base of the scalp (This form represents 3 runs for each substance and hair sample).

* Example: hair length is 6 cm and are asked to analyze each 2 cm from the base of the scalp.


What analytical methodology used?

Echevarne use for this type of analysis coupled with liquid chromatography tandem mass spectrometry (LC-MS/MS ), considered internationally as the model for this type of analysis.

What criteria or recommendations used for this type of analysis?

Echevarne used cut off criteria of the European Workplace Drug Testing Society and Society of Hair Testing ( EWDTS ) in his document: "Drug and Alcohol Testing in Hair, Collection and Analysis". For each substance and / or metabolites this scientific association defines a cut off concentrations. Exceeding them the result will be considered positive.

What documentation and information must be provided to the laboratory?

With the hair sample, if it is not collected in the laboratory, you must complete the application document for hair drug testing.
If it is necessary to identify the person, sampling should be done in one of our centers by Echevarne profesionals.

What are the limitations of this test?

  • It is not possible to extrapolate the founded concentrationsto inform about the dose consumed.
  • Not determine whether a person has used drugs on a particular day.
  • It is not possible to confirm whether the person is intoxicated.