A new study has confirmed what many have already suspected—drug use in the Czech Republic is increasing.

According to wastewater analysis conducted by the TG Masaryk Water Research Institute (VÚV), cocaine is the most common drug in Prague and Pilsen.

At the same time, methamphetamine (pervitin) dominates in Ústí nad Labem and Ostrava. The study also found that marijuana use is rising, with its presence in public spaces becoming more visible, particularly in Prague.

Gone are the days when smoking a joint was done in secret; today, the scent of marijuana is replacing cigarette smoke on the streets of the capital. However, how do scientists identify which drugs are being consumed and where? The solution was discovered in the wastewater analysis—novel, anonymous, and highly accurate for gazing at national drug consumption patterns.

How Scientists Track Drug Use Through Wastewater

Each year, researchers take wastewater samples from large Czech cities and test them for traces of drugs. It is a straightforward, objective way to see what people are using. The data is then sent to the European Union Drugs Agency (EUDA), allowing comparisons with other countries.

“The method provides an objective and anonymous view of drug consumption in the population. Thanks to it, we know which substances are the most popular and where their use is most widespread,” explains Věra Očenášková, the project leader at VÚV.

However, why don’t scientists sample unknown wastewater in one day? The reason is that people’s behaviour is different during the week. Friday and Saturday nights are party nights, and Mondays are recovery and sleep days. Scientists sample wastewater throughout a week to determine the best estimate of drug use.

The collected samples are then analysed using a liquid chromatograph – a state-of-the-art device worth CZK 15 million.

This device can accurately detect what substances have flowed through the city’s sewers. One analysis takes about two hours and provides a detailed overview of the presence of various drugs.

Drug map of the Czech Republic

In Prague alone, several kilograms of cocaine are flushed down the drain every week—equivalent to hundreds of thousands of individual doses. Addiction specialist Michal Miovský believes this information is crucial for law enforcement and public health efforts.

“Based on this data, authorities can determine where drug trafficking is most active and where prevention efforts should be focused,” he explains.

Prague remains the epicentre of cocaine use, but high concentrations were also found in Pilsen, Brno, and České Budějovice.

Marijuana is the most prevalent and accepted substance in the Czech Republic. “Marijuana stays in the body for a long time, which is why its levels tend to be high in wastewater,” explains Kateřina Grohmannová from the National Drug Monitoring Centre.

The highest levels of marijuana use were recorded in České Budějovice, Pilsen, and Prague, though significant concentrations were also found in Brno, Karlovy Vary, Ostrava, and Ústí nad Labem. According to experts, marijuana popularity is universal among generations, with no change in consumption patterns over time.

Ketamine is increasing, particularly in Prague, Ústí nad Labem, Brno, and Pilsen. The increasing trend of ketamine is something to worry about because the abuse of the drug has severe health implications. The death of actor Matthew Perry, in which ketamine was involved, has put its risks in the spotlight again.

Pervitin: The Czech Republic’s Long-Standing Meth Problem

Pervitin has long been a significant issue in the Czech Republic. It remains most common in Ústí nad Labem and Ostrava, regions that face significant socio-economic difficulties. The drug’s low price and easy availability make it particularly appealing.

Three years ago, pervitin was even detected in wastewater samples taken from schools in the Chomutov region, indicating that children under the age of 15 are experimenting with the drug. The study also found high levels of pervitin use in Pilsen, České Budějovice, and Brno.

Ecstasy: The Weekend Party Drug

Ecstasy (MDMA) remains a favourite among partygoers, with the highest levels found in Prague and Ostrava, followed by Pilsen, Brno, and České Budějovice. Unlike other drugs, ecstasy use is seasonal and peaks on weekends, which is reflected in the wastewater data—concentrations of MDMA spike on Fridays and Saturdays, then drop significantly during the week.

Would you like us to write about your business? Find out more

The Czech police uncovered cocaine worth 750,000 crowns and a cash sum in the car of a foreigner coming from Africa whom they have accused of drug dealing in Prague and who faces up to ten years in prison, if convicted, Prague Police spokeswoman Eva Kropacova said on Friday.

Police found over fifty bags of drug already prepared for the sale, and two bags with 200,000 Kč and EUR 500 in cash.

The suspect has several dozens of regular clients who bought drugs from him. According to police, the 34-years-old dealer has been selling drugs since 2008.

The man could face up to 10 years in jail.