When any substance is consumed (prescribed or illegal), it is processed in the body and the by-products – metabolites – penetrate into hair follicle with the blood stream. As the hair grows, these metabolites stay entrapped within the hair, and the strands contain a proportional amount of metabolites to the amount of toxins consumed.

As the hair grows, these metabolites remain in the strands and cannot be removed without destroying the hair. Analysis not only can detect these metabolites, but also can provide information of quantity consumed together with the frequency of consumption. Every time the hair is cut, you discard the oldest part of your “history,” but the part that’s important for a lab is closer to the scalp.

To obtain a sample for a test, hair is collected from different parts of the head; most hair testing labs use 1-1/2 inches of hair – that corresponds to 90 days of growth (head hair normally grows at about 1/2 inch per month). If there is not a sufficient amount that can be collected from a head, a sample can be obtained from any part of the body; depending on the rate at which your hair grows, body hair can give history of use for a period longer than 90 days.

Generally, labs will test for:

Cocaine,

Marijuana,

Opiates,

Methamphetamine,

Amphetamine,

Phencyclidine (PCP).