Hair follicle testing provides a method for detecting substance use over an extended period. Unlike urine or blood tests, which offer a relatively short detection window, hair analysis can reveal a history of substance consumption spanning several months. This is because substances become embedded in the hair shaft as it grows.
The primary benefit of hair follicle drug testing lies in its ability to identify patterns of substance use that may not be apparent through other testing methods. This extended detection window is particularly valuable in situations where long-term substance use needs to be assessed, such as in legal or employment settings. Historically, hair analysis has been used in forensic investigations and has become increasingly prevalent in workplace drug screening programs.