Hair

Hair is a suitable examination material for substance misuse testing. Independent of the method in which the drug was taken (oral, nasal, intravenous or inhaled), it will become embedded within the hair structure and be stored long term. Sample Material: In principle, every form of body hair is suited for foreign substance abuse testing (head, shoulders, chest, pubic hair, etc.). However, in general a sample (with the thickness of a pencil) is taken from the head as close to the scalp as possible. Individual hair strands on their own are not suitable for analysis. Contamination and Manipulation: Due to the exposed location of the hair, the sample can be effected by external factors. For example, the hair of a person who does not take any drugs but comes into contact with individuals who do take drugs, can have a contaminated hair sample due to cannabis smoke or cocaine powder. In order to exclude a false positive laboratory result through the cause of such stipulating external factors, the sample material should be washed once or several times before the extraction. If in doubt, the positive laboratory result can be verified and it can be checked if the last wash liquid was free of smoke material. Drugs Hair analysis provides a much longer drug detection time frame for the determination of a past consumption of drugs and medications than a blood or urine analysis test. The consumed substances as well as their metabolites become stored within the hair roots and remain for a long period of time within the hair matrix. The exact time window for detection is dependent on hair length. For example, with an average hair growth rate of about 1 cm per month, by the means of a 12 cm long hair sample a person's drug consumption for an entire year can be examined.