The EMCDDA uses a variety of methods and tools to monitor prevalence and patterns of drug use in the general population in Europe. One innovative new approach being trialled by the agency is hair drug testing, which can detect illicit drugs and their breakdown products (metabolites) in hair. The method involves collecting hair samples from volunteers and analysing them for traces of substances which may have recently been consumed. This form of testing can be used in combination with surveys to validate self-reported information and is a useful approach for monitoring drug use in specific settings.

In a pilot project involving partners in Italy and Portugal, the EMCDDA is testing this method alongside a web-based drug use survey modelled on the European Web Survey on Drugs. The project involves recruiting volunteers in drug-checking services, music festivals and raves in the two countries concerned and collecting hair samples from them for drug use screening. After providing a few strands of their hair, participants are asked to fill in an online questionnaire on their drug use behaviour. The hair sample is sent for analysis, stored anonymously and destroyed after the study. The purpose is to compare what participants think they consumed against the evidence revealed through the chemical analysis of the hair samples. The first sampling will be carried out at events in Spring and Summer 2022 and results reported later this year.

Drugs enter hair through the blood, sweat and sebum as well as from the external environment. Since it is possible to detect most compounds ingested in a defined timeframe prior to sampling, hair analysis allows for a re-creation of the drug exposure history.

While not representative of the general population, complementary drug monitoring methods, such as these, can provide valuable additional information about variations in use among different groups of people who use drugs. Although this method cannot assess levels of consumption, it can provide important insights into substances used.