Hair follicle testing is a method of drug and alcohol detection that analyzes a hair sample to identify substance use over a longer period than other testing methods, such as urine or blood tests. Unlike these methods, which typically detect recent use, hair follicle tests can provide a historical record of substance consumption, potentially spanning several months. A key compound analyzed in these tests to determine alcohol consumption is ethyl glucuronide (EtG), a minor metabolite of ethanol.
The ability to detect alcohol consumption over an extended timeframe is particularly beneficial in legal and clinical settings. For instance, it can be used in child custody cases, probation monitoring, or substance abuse treatment programs to verify abstinence or identify relapse. Historically, direct detection of ethanol in hair proved challenging due to its rapid metabolism and potential for external contamination. The development of EtG analysis has significantly improved the reliability and accuracy of alcohol detection using hair follicle testing.