A hair drug test is a type of test that is not only accurate, but comprehensive: aside from testing up to 7 different types of drugs at once (marijuana, cocaine, opiates, amphetamines, methamphetamines, ecstasy and PCP) it provides an up to 90 day history of drug use, dating from the time of the hair collection. A variety of businesses and organizations use hair drug testing in their employment screening process - among them Kraft Foods, Anheuser Busch, the federal government and police departments around the country (see this MSNBC article for more information). Parents also use hair drug tests as part of their efforts to keep their kids drug-free.
A hair drug test works so well at establishing a lengthy drug history because of the way drugs are ingested and work through the body. Drugs of course enter the bloodstream when used - and the blood nourishes hair follicles as they grow. The drug will show up in the hair within a week after it has been used. The industry standard is to provide at least a half inch of hair to get results - less than that will not be accepted by a lab. This half inch of hair will give you a 30 day drug history. The three hair drug tests provided by Home Health Testing (here, here and here) will show you up to, but no more, than 90 days of drug use history.
Drug testing has grown increasingly common in our world, and hair drug testing in particular. The hair drug test has grown in particular because of what it offers to the market - a long window of detection, the convenience of the collection, and the accuracy of the test's accuracy. These tests are available for purchase at Home Health Testing's website http://www.homehealthtesting.com/hair-c-21_29.html.