BACKGROUND Drug consumption rooms offer heroin and cocaine consumers a secure and hygienic environment including medical and social guidance. Despite the support and mentoring, only sparse information is available about how drug quality, drug prices and user expectations match at these locations. The present study reports analysis of these three parameters in two drug consumption rooms in Luxembourg.

METHODS Drug users were invited to participate in the project by handing in a few milligrams of the product they planned to consume for chemical analysis and filling out a short questionnaire about the price and their expectations. After consumption, they were asked to report the experienced effects. Drug quality was accessed using LC-Q-ToF and HPLC-UV, and a statistical analysis was carried out of the questionnaires that were correctly filled out.

RESULTS A total of 513 drug samples have been analyzed. Most consumers were looking for the relaxing/calming effects of heroin and the stimulating effects of cocaine, but they generally overestimated heroin potency and underestimated cocaine potency. No strong correlation based on Spearman's ρ between drug user estimations, drug prices and drug quality was found.

CONCLUSION To the best of our knowledge, this study is the first to combine drug analysis with heroin and cocaine user feedback about expectation, drug prices and drug effects. The analytical results were of great interest for users and the staff working at the drug consumption rooms. They may be a strong supplementary communication tool for health care workers when discussing effects and risks of highly toxic substance consumption.