Background: Drug checking services (DCS) provide information about drug content and purity, alongside personalized feedback, to people who use drugs; however, the demographic and drug use characteristics of DCS clients are rarely reported. This paper describes these characteristics for clients of the Dutch DCS, the Drug Information and Monitoring System (DIMS). 

Methods: 1,530 participants completed a pen-and-paper questionnaire at one of eight participating DCS in the Netherlands in 2018. 

Results: The participants were mostly highly educated males in their twenties with no migration background. Experience with drugs prior to coming to the DCS was common. Only 0.7% indicated they had never used any of the twenty drugs studied. 93% of participants reported use of ecstasy or MDMA with an average of 6.3 years since first use. 

Conclusions: These results indicate that drug checking can be a valuable tool for public health services as it facilitates access to more difficult-to-reach communities who use drugs. It is unlikely that DCS encourage drug initiation, since almost all people who visit the Dutch DCS already report experience with drugs. However, DCS should be aware that their services might not be easily accessible or attractive to all demographic groups.