It is a common fact, that drug tests are conducted on biological specimens, like blood, hair, urine, and saliva. Nowadays, hair drug testing is also fast gaining momentum, due to various factors, like easy sample collection, longer detection periods and more accuracy. However, the main advantage of the hair drug test is the longer detection period.
Hair Follicle Drug Testing
As the name rightly suggests, this drug test involves hair, instead of blood, saliva or other such biological specimens. This is because, drugs and their metabolites (substances formed in the body, when it metabolizes a certain drug) that enter the blood stream of the user, will also settle in the hair shafts, and are retained there for a longer time.
Hair sample is collected and tested as per the guidelines set by the Society of Hair Testing. Usually, around 60 milligrams of hair is collected for a standard hair drug screening test. A single strand is not enough for testing. The hair sample is washed thoroughly, with an organic solvent, followed by water. Even the wash may be tested later for presence of drugs or their metabolites. After washing, hair is cut into small pieces and a small portion is subjected to immunoassay techniques using ELISA. This screening is followed by confirmation tests, like gas chromatography and mass spectrometry. Both positive and negative results are confirmed, before declaring the outcome.
While blood, urine or saliva samples retain drug particles as well as their metabolites for a few days, hair strands retain them for months. Again, this depends on factors like the type of drug, amount used, frequency of use, and the nature of hair sample. Even the metabolic rate, age and health of the person may affect the detection period of drugs. Hair drug testing is usually used for screening cocaine, marijuana, opiates (like morphine, codeine and 6-monacteyl morphine), methamphetamine, amphetamine, ecstasy, and phencyclidine (PCP).
While the detection time for alcohol is up to two days of consumption, single use of cocaine/marijuana may not be detected through a hair follicle drug test. However, in case of regular use of cocaine or marijuana, the detection time is up to 90 days. For all other drugs, except LSD (lysergic acid diethylamide), the detection period is said to be up to three months or 90 days. Hair drug test detection time for LSD is up to three or four days only. In case of methadone, the detection time can be more than 100 days. In short, 90 days is the standard detection time for hair drug screening, for a wide range of drugs. However, it may vary for LSD, cocaine and marijuana. In some cases, the hair drug test may detect the exact time of usage too. It has also been noted that certain drugs and their metabolites can be detected through hair testing, for more than a year, provided the hair is long. If there is no hair on the whole body, other specimens, like urine or blood may be collected for drug test.
Hair follicle drug testing is said to be reliable and accurate; as it is not possible to detox hair, even though, there are some products that claim to do so. Some people go bald before hair drug screening, so as to avoid the test. However, this may prove futile, as body hair can also be taken as sample for this test. As hair follicle drug test detection times are around 90 days or more, it will not be possible for you to escape a positive result, unless you stop using drugs. So, if you want to avoid a positive drug test, all you can do is to avoid use of drugs.