Peer-led drug checking in Chile: a case study of the country's first harm reduction service at electronic music events.

Abstract

The health risks for people who use drugs (PWUD) in Chile are exacerbated by evolving drug markets, unpredictable supplies, and the limited availability of harm reduction services. Community-based drug-checking programs have shown effectiveness in reducing some of these risks; however, regional evidence remains limited. In 2024, Reduciendo Daño (RD), a Chilean non-profit organization, conducted a peer-led drug-checking program, attending 22 electronic music events in Santiago. Event attendees interested in testing their substances placed small samples on the designated testing surface, after which staff conducted rapid colorimetric analysis and recorded the samples' characteristics and test results. RD staff analyzed 992 samples; most of the samples, according to the event attendees, were MDMA (78%), followed by ketamine (9%), cocaine (6%), tusi (5%), and other substances (2%). The analysis showed that more than 80% of the samples purported MDMA contained MDMA. 10% of the samples expected to be MDMA contained MDA instead, and the most common adulterant in MDMA samples was methamphetamine (8%). Cocaine was found in all samples expected to be cocaine (n = 62), but more than two-thirds of the samples (71%) were adulterated. Tusi samples (n = 48) were heterogeneous. Ketamine was the only substance detected in 42% of all the ketamine samples: 33% had a combination of ketamine and MDMA, 15% contained ketamine plus other substances, and 10% had no detectable substances. Excluding tusi, about 70% of the samples matched the attendees' expectations, 14% were adulterated, and 16% lacked the expected drug. This peer-led harm reduction intervention provided timely and practical information to PWUD. The findings indicate that MDMA was the most common substance tested among attendees of electronic music events, that tusi showed considerable variability in its composition, and that cocaine was frequently adulterated with other substances. Together, these results underscore the need to strengthen and expand harm reduction initiatives in Chile, such as community-based drug checking programs, that provide information about substances and education on safer drug use.