I am a pharmacist with master's degree in neuroscience. I am currently working with drug checking in my doctoral project, which I do in collaboration with an NGO called ‘É de Lei’, one of Brazil's oldest harm reduction organizations, and where I work as a volunteer since 2015.

Drug checking is a public health intervention that allows people to have your drug chemically analyzed, receive information and counseling. It is also useful for obtaining information like patterns of use and adverse reactions. It has been used as a harm reduction strategy for years in many countries. However, in Brazil, it is only emerging and there are no scientific studies. So, the main objective was to set the basis for the development of a community-based drug checking service in Brazil and study its impacts.

Data collection was carried out in electronic music parties held in 2021 in the city of São Paulo. The harm reduction area offered several other services such as psychological support and informational material. The drug checking service used colorimetric reagents as field technique. Participants also answered a self-administered questionnaire on sociodemographic data, pattern of substance use, drug effects, reactions to the result of the analysis as well as an evaluation of the service.

A total of 126 samples were analyzed. Approximately 23% did not contain the expected substance and 17% contained some type of mixture. The questionnaire showed that 7% of participants gave up using the substance after knowing the test result, another 14% reported that would use less amount and 3% would avoid mixing with other substances. Most respondents (70%) had never used a drug checking service and 88% rated it as very useful.

These findings suggest that electronic music party attendees positively engage with harm reduction services when offered. The strength of peer work increases trust and a culture of care and solidarity within the community. The high rate of adulteration represents a great risk and shows the potential of drug checking services to prevent the inadvertent use of unknown substances, to reduce the amounts ingested and thereby decreasing the risk of intoxication.