Drug use is only evident for a brief time in blood and urine. Traces of drugs are present in hair for longer periods.
Scanning a lock of hair over its entire length results in a detailed timeline of the person's drug use, sometimes going back months in the past. Within an hour, it is possible to determine whether someone has taken a drug such as cocaine, amphetamines or cannabis – and when they took it. This method can provide evidence in court cases and reveal the use of doping in humans and prohibited growth agents in livestock. This is one of the ways in which Wageningen UR works on the quality of life.