Hair testing has been used for nutritional deficiency testing, trace metal detection, and testing for learning disabilities and mental illnesses since the early 1970s.[5] The first analysis of drugs in hair was published by Baumgartner in 1979;[6] wherein a radioimmuno assay was used to detect morphine.[6] Until recently though, the use of hair testing was limited and not well received among the forensic authorities. By the mid-1980s, hair analysis evidence had been used in American courts in a number of criminal, military, and child custody cases and this approach is anticipated to expand into additional legal areas.[7] Among other uses, hair analysis for cocaine is finding its niche in divorce proceedings, competency in child custody hearings, neonatal testing, insurance cases, and health surveys in drug treatment programs.[8] It is thus clear that hair analysis for cocaine use has far reaching applications in epidemological, clinical, administrative, and forensic fields.[5] Perhaps of more direct impact to the bulk of the US population, it is now not uncommon for employee applicants to be required to submit a sample of hair as a condition of pre-employment, and, less commonly, to do the same at random times during employment.

Hair analysis and analysis of blood or urine both have their benefits. Tests of blood or urine are acceptable in courts and have been established for many years. Unfortunately, people have discovered a number of ways of cheating on both blood and urine test.[9] In contrast, hair testing provides virtually no opportunity to cheat. The hair sample is taken in the presence of the tester who retains legal custody (chain of evidence) of that sample. The long time frame available for hair collection is another advantage of hair analysis over blood or urine analysis. Blood and urine both have a short time frame for utility as most drugs are completely metabolized or excreted within three days. Cocaine hydrolyzes too quickly and cannot be detected by urinalysis, although its metabolites can be detected within three days of ingestion. In contrast, cocaine remains in hair for the lifetime of the hair allowing for a positive confirmation weeks or even months after ingestion. The hair collection procedure is also not as invasive or embarrassing as blood or urine testing. Segmental analysis of hair can provide a time history of drug use making it especially useful for rehabilitation programs. Urine and blood testing have an advantage in determining the exact amounts of the drugs used and recent drug usage, while hair analysis techniques yield no correlation between time and the amount of the drug used. [10]