Hair drug test in another popular and most accurate method in detecting the drug abuse. The main advantage of this test is, it can detect small amounts of drug, even though they are consumed before 60-90 days. This test is conducted by testing the hair of the concerned person who is suspected for drug abuse. The longer the hair is the more easy to find the drug presence. This test uses the enzyme immuno essay to detect the drug and its metabolites.

Using hair tests one can detect the drugs like cocaine, marijuana, opiates, methamphetamine, and phencyclidine. Since all above drugs are identified as the most popularly abused drugs by the Federal government, these hair drug tests are found to be effective. Many of us still have a doubt about how drugs can be detected in the hair. Let us see how. After consuming the drugs, they pass through the blood stream and circulate to different parts of the body along with the blood. Hence they also enter the hair follicle cells. As the cells grow these drug metabolites are eventually trapped within the cells and stay in the hair for much longer time.

For testing the hair, few strands of hair are cut as close to the scalp whose length is a minimum of 1.5 inches. This 1.5 inch strands can tell the 90 day history of the drug consumption. Since other processes of drug detection are limited to 72 hours of time, this drug test is quite helpful because of the availability of wider window of drug detection. Moreover, this test is non-invasive and there is no chance to manipulate or adulterate the sample. These many benefits from a single test made it more effective than the existing procedures of urine and saliva analysis.