Hair drug testing is done by using some strands of hair. When both the blood and the Urine are not infected or not showing any results then the hair test is done.
Initially hair analysis is done and then the test is done. The drugs and the metabolites are being absorbed by the use of drugs. They stay even after one week in hair after the drug is consumed. It also retains the metabolites for a longer period.
Absorption depends upon the type of the hair. After the consumption of the drug hair is filled with markers. If the number of markers is more it indicates the amount of drug consumed is also more. The two types of markers which are generally found are fatty acid ethyl esters (FAEEs) and ethyl glucuronide (EtG).These markers help us to detect the content of the drug in the body.
FAEEs enter into the hair through cells called keratinocytes which are responsible for growth in the hair and it has a more protective layer of fat for its growth. The hair grows at the rate of 0.03 mm per day on the surface of the skin.
After the sample is collected then the hair is bleached and washed. Even then the FAEEs are not changed or affected by the usage of those cosmetic methods for treatment.
However, there are some disadvantages using hair test analysis:
- When the hair is exposed to the free air then some of the metabolites get diluted in the hair and make the test complicated.
- In some cases if the people in the surroundings are snorting some drugs hair may be infected.
But on a whole the person who is consuming much drug has much positive result than the other who is exposed to the surrounding.