Urine: Results of a urine test show the presence or absence of drug metabolites in a person’s urine. Metabolites are drug residues that remain in the body for some time after the effects of a drug have worn off. It is important to note that a positive urine test does not necessarily mean a person was under the influence of drugs at the time of the test. Rather, it detects and measures use of a particular drug within the previous few days and has become the defacto evidence of current use.
Hair: Analysis of hair provides a much longer “testing window,” giving a more complete drug-use history going back as far as 90 days. Like urine testing, hair testing does not provide evidence of current impairment, but rather only past use of a specific drug. Hair testing cannot be used to detect for alcohol use. Hair testing is the least invasive form of drug testing, therefore privacy issues are decreased.
Oral Fluids: Saliva, or oral fluids, collected from the mouth also can be used to detect traces of drugs and alcohol. Oral fluids are easy to collect (a swab of the inner cheek is the most common collection method), harder to adulterate or substitute, and may be better at detecting specific substances, including marijuana, cocaine and amphetamines/methamphetamines. Because drugs do not remain in oral fluids as long as they do in urine, this method shows promise in determining current use and impairment.