Wastewater Analysis Reveals Rising Ketamine and Crack Cocaine Use in Switzerland

Wastewater doesn't lie, and the latest data from the Swiss underground tells a troubling story. The Swiss Federal Institute of Aquatic Science and Technology (Eawag) has released explosive figures from the first half of 2025, revealing a dramatic shift in the nation's drug habits. While Switzerland has long monitored substance use, this year's analysis exposes a sharp, undeniable pivot toward harder, more volatile substances. The sewers are flagging a significant surge in the consumption of ketamine and crack cocaine, painting a gritty picture of evolving addiction patterns that traditional surveys often miss.

Eawag experts, utilizing the substance monitoring portal Dromedario, have bypassed uncertain sales figures to go straight to the source. By analyzing chemical markers in the water supply, they have confirmed that the Swiss drug landscape is becoming increasingly fragmented and potent. This isn't just a statistical blip; it is a concrete warning signal rising from the infrastructure itself. As the country grapples with these findings, the data demands immediate attention from policymakers and health officials alike.

Zurich is now the undisputed epicenter of Switzerland's rising ketamine crisis. The data reveals that levels of the dissociative anesthetic in Zurich’s wastewater are significantly higher than the average across all ten monitored Swiss locations. While ketamine has legitimate medical applications, the sewage analysis points to a far more recreational reality. The concentrations skyrocket during the weekends, confirming that the drug—known on the street as "Special K"—has firmly entrenched itself in the city's club and rave scene.

The disparity between the work week and the weekend is stark. This temporal spike provides strong evidence that the consumption is driven by partygoers rather than patients. Zurich’s nightlife is inadvertently flushing the evidence of its habits into the public record, showing a city that is partying harder and more dangerously than before. This surge in recreational anesthesia presents a unique challenge for emergency services and harm reduction groups operating in Switzerland's largest city.

The alarm bells are ringing equally loud for crack cocaine. Eawag’s analysis tracked AEME (anhydroecgonine methyl ester), the specific degradation product of crack, and found levels surging well above previous benchmarks in 2025. The crisis is not confined to a single metropolis; while Zurich remains a major hub, the eastern city of Chur has emerged as a significant hotspot, registering values well above the Swiss average. This geographic spread indicates that the crack epidemic is permeating beyond the usual suspects.

Much like ketamine, the consumption of crack cocaine follows a distinct temporal rhythm, with values spiking significantly on weekends. This pattern suggests a highly active, cyclical market that intensifies when the work week ends. The presence of such high levels of AEME in the wastewater of Chur—a smaller urban center compared to Zurich—suggests that the availability of high-purity, smokable cocaine is penetrating deeper into the Swiss demographic than previously estimated.

In a surprising contrast to the surge in dissociatives and stimulants, the consumption of crystal meth and cannabis appears to be waning. The analysis shows that methamphetamine levels have continued a slight downward trajectory that began when specific measurements started in 2021. Despite being one of the most dangerous drugs on the market, crystal meth is losing its foothold in the Swiss wastewater data, offering a rare glimmer of positive news in an otherwise concerning report.

Similarly, cannabis is seeing a retreat. The levels of THC-COOH, the metabolite excreted after marijuana consumption, were lower in the first two quarters of 2025 compared to previous years. This decline suggests a potential shift in consumer preference, perhaps as users migrate toward the newer, more potent synthetic options or simply reduce intake. While cannabis remains a staple of the drug culture, the data confirms it is currently taking a backseat to the rising tide of ketamine and crack cocaine.

This report serves as a critical wake-up call for Switzerland’s public health strategy. The data proves that the drug landscape is fluid and capable of rapid, dangerous shifts. As NGOs warn that more can be done to prevent addiction, the Eawag findings provide the hard evidence needed to pivot resources where they are most needed: harm reduction for crack users in Chur and targeted interventions for the party scene in Zurich.

Wastewater analysis has moved beyond academic curiosity; it is now a vital tool for real-time societal diagnosis. The rise in crack and ketamine suggests a population seeking more intense, immediate highs, a trend that carries severe health risks. Switzerland must now confront these numbers head-on, using this unvarnished data to adapt its drug policies before the weekend spikes become a permanent baseline.