Hair testing remains to be one of the most flawed forms of drug testing. It works by detecting various drug metabolites that have been passed on from the blood stream into the hair follicle, and this follicle can tell you whether or not you have taken drugs in the last three months. This also includes patterns of usage, so if you smoke pot one month and not the next, this will also show up in the test. If you have very short hair, then hair can be taken from any other part of the body. It is worth knowing however that if the hair is absolutely clean, it will cause a false positive.
The Drug Test
As you can see, even something as small as a microscopic powder can change the results of a drug test, and to make things even worse, various contaminants can cling to dark hair and this can cause African-American hair to be more susceptible to false results. In fact, those with African-American hair are between 10-50 times more likely to show a false positive on a hair follicle test. Shampoo manufacturers have tried to combat this by working on the formula used in each shampoo, but this hasn’t been brought into effectiveness yet. Until this is the case, the original follicle shampoos really are the best and only option if you are a stoner who is facing a drug test via hair follicle removal.
Just remember to wash your hair thoroughly before the test, and make sure that you use the right shampoo for the job. This will almost guarantee you a false positive, so even if you have smoked pot recently, you still have a very low chance of showing up on the test. You should however avoid smoking pot directly before the test to avoid any accidental diagnosis during your hair test for drugs.