Cocaine dominates in Copenhagen, fentanyl spikes in Fredericia

A new report from the Danish Health Authority reveals stark local differences in drug use across Denmark, based on wastewater analysis from 29 treatment plants covering roughly half the population.

The study, conducted by researchers at Aarhus University’s Department of Forensic Medicine, shows cocaine and other central stimulants are most prevalent in major cities, with Copenhagen and Aarhus recording the highest levels. Amfetamine use is particularly concentrated in Slagelse, Copenhagen SW, Esbjerg, and Køge, while MDMA is most common in the capital.

Opioid use, including tramadol and oxycodon, is generally lower in urban centers but appears more frequently in suburban areas of Copenhagen and Aarhus. The report notes that legal prescriptions for pain management may contribute to these patterns, as the analysis cannot distinguish between legal and illegal consumption.

Fentanyl, measured for the first time in 2025, shows low nationwide levels except in Fredericia, where concentrations were described as “remarkably high.” The Danish Health Authority has notified local officials and police but cautions that the finding is based on limited data.

Weekend spikes were observed for cocaine, MDMA, and alcohol, with levels two to three times higher than on weekdays. Other substances, including amfetamine, methamphetamine, ketamine, THC, and opioids, showed no significant weekly variation.

Cocaine remains the most widely used drug in Denmark, with an estimated total consumption of 7 tons in 2025.