Chemist and drug checking service coordinator of Échele Cabeza. He has done research on the use of psychoactive substances in Colombia and has participated in different harm reduction projects both in universities and in nightlife contexts.

The growing popularity of Tusi in Colombia reflects a change in the drug market and young people's preference for a new product that has recently appeared in other countries in the Americas and Europe. Although different drug checking services worldwide have reported the composition of Tusi samples, Échele Cabeza has recorded the evolution of its components for a decade since its appearance in Colombia.

Échele Cabeza's analytical service is based on the use of colorimetric reagents, but thanks to collaboration with research groups from universities, international organisations specialised in harm reduction and the Colombian Drug Observatory, different analytical techniques have been used, such as TLC, FTIR and GC/MS, which have made it possible to clarify the complexity of the tusi phenomenon.

Since 2023, Échele Cabeza has included fentanyl and benzodiazepine test strips. This has broadened the range of substances that can be detected in Tusi. Fentanyl has not been detected in any of the samples. However, benzodiazepines have been detected in more than 40% of the samples tested. Although ketamine and MDMA have been detected in around 90% of samples, the presence of multiple substances implies risks for users who underestimate the potential harm of poly-drug use. This is why working with peers is key to developing specific risk and harm reduction recommendations, especially in the context of nightlife and electronic music parties.

Accordingly, the presentation will show the relevant results of the tusi analysis, resulting from the 10 years of work carried out. It will also present data related to the patterns of use of a generation that has tended to use synthetic drugs in a country traditionally known for producing cocaine.