Drugs – Population-level use by region

Long-term increase in drug use

THL’s nationwide wastewater-based epidemiology shows marked regional differences in the use of different drugs and in how patterns of use have changed over time. On average, drug use is highest in large cities in southern Finland (Figure 1).

Over the long term, overall drug use increased steadily until early 2021. For example, the combined use of amphetamine, methamphetamine, methylenedioxymethamphetamine (MDMA, “ecstasy”) and cocaine was approximately four times higher than at the start of the wastewater study in 2012. This conclusion is based on data from the ten cities and their surrounding areas that have been included since the outset, covering around 43% of Finland’s total population.

Amphetamine is widely used throughout Finland. Its long-term upward trend continued until spring 2021, after which levels began to decline. In 2022 and 2023, amphetamine use in sampling cities remained lower than in previous years. In 2024, however, use increased again in most cities.

Cocaine use has risen sharply since the launch of the nationwide wastewater study in 2012. Although use is still most concentrated in and around the Helsinki metropolitan area, the 2024 results show that cocaine use has also increased clearly in other cities, extending as far as northern Finland. Even though cocaine use levels remain below the European average, including in the metropolitan area, cocaine now accounts for a substantial share of overall drug use, particularly in southern Finland. In northern regions, use remains clearly lower despite recent growth.

By contrast, ecstasy use has remained comparatively stable over the long term.

Timing of findings provides insight into patterns of use

According to wastewater analyses, cocaine and MDMA use is strongly concentrated on weekends. This suggests recreational use, and partly different user groups compared with drugs such as amphetamine, methamphetamine or synthetic cathinones.

These patterns become particularly pronounced when large public events take place within a treatment plant’s catchment area during the sampling period. In Tampere, for example, longitudinal monitoring revealed unusually high cocaine use in August 2023 and again in August 2025 (Figure 5).

Similarly, during the March 2024 sampling period at the Jämsä wastewater treatment plant, exceptionally high weekend use of cocaine (approximately 3,000–3,500 mg per 1,000 inhabitants per day) and MDMA (approximately 1,000–1,500 mg per 1,000 inhabitants per day) was observed. A major public event was held in Jämsä at that time, and for this reason the city’s 2024 results were excluded from the nationwide comparison shown in Figure 1.

Integrating data for a more comprehensive picture of drug use in Finland

THL integrates population-level data derived from wastewater studies with research findings and register data from other sources. This approach provides a more reliable and multidimensional overview of the drug situation in Finland. Combining datasets also enables innovative assessments of otherwise difficult-to-measure phenomena, such as the financial value of drug markets or estimates of drug consumption relative to quantities seized by law enforcement authorities.

Previously, results from the nationwide wastewater study closely mirrored trends in drug-impaired driving statistics. More recently, however, the trends have partially diverged (Figure 2). In 2024, this difference was largely driven by amphetamine, which appeared more frequently in wastewater than in 2022, but less often in suspected drug-impaired driving cases. In addition, the rise in cocaine use is more pronounced in wastewater-based consumption estimates than in the number of positive tests among drug-impaired drivers. Overall, the total number of suspected drug-impaired driving cases has also declined markedly since its peak in 2020.

Jos verrataan jätevesitutkimusten perusteella laskettua käytetyn huumeen määrää Suomessa tehtyihin huumetakavarikoihin, voidaan arvioida, että vuonna 2014 amfetamiinia, metamfetamiinia ja kokaiinia käytettiin 5–10-kertainen määrä verrattuna takavarikoituun määrään.

Comparisons between wastewater-based estimates of drug use and drug seizures suggest that in 2014, amphetamine, methamphetamine and cocaine were consumed in quantities five to ten times greater than the amounts seized.

Rising drug use has increased the monetary value of drug markets

In 2014, the estimated value of Finland’s amphetamine market was EUR 70 million, while the methamphetamine and cocaine markets were valued at around EUR 10 million. These findings were published in full in the journal Science of the Total Environment in 2016, building on Finland’s first nationwide wastewater study published in the same journal series in 2014.

Over the past decade, the growing use of illicit drugs has substantially increased the monetary value of drug markets. Based on wastewater-derived consumption estimates, the market value of amphetamine in Finland in 2024 was approximately EUR 120–150 million, cocaine EUR 87–96 million, and methamphetamine around EUR 5 million. The most pronounced growth over this period has occurred in the cocaine market.

Substance purity affects consumption levels

When trends in wastewater-based estimates of total drug use are combined with information on the purity of drugs seized by law enforcement, short-term correlations are often observed. Periods during which purer substances are available on the market tend to be associated with higher overall levels of consumption.

For example, in 2017 the average purity of seized amphetamine and methamphetamine declined significantly compared with 2016. The average purity of methamphetamine fell from 31% to 17%, and that of amphetamine from 25% to 17%.

In earlier years, however, unusually pure amphetamine and methamphetamine were available on the Finnish market. This likely contributed to lower observed use levels in the Helsinki metropolitan area in 2017 compared with 2016, as well as to the exceptional increase in use seen in 2014 and 2015. Over longer time spans, the influence of purity fluctuations on overall consumption tends to diminish.

Early identification of changes in the drug situation

In addition to its representativeness, a key strength of wastewater-based monitoring is the near real-time information it produces. This allows emerging changes in drug use to be identified at an early stage. Alongside the nationwide study, continuous longitudinal monitoring is conducted approximately every two weeks in the catchment areas of three large wastewater treatment plants: Helsinki, Turku and Tampere (Figures 3–5). Several major shifts in Finland’s drug situation were first detected through monitoring wastewater in the Helsinki metropolitan area.

Examples of observed changes

• In 2016, methamphetamine appeared alongside amphetamine, which had been Finland’s dominant stimulant for decades, within a very short time.
• In 2020, despite the exceptional societal restrictions introduced during the COVID-19 pandemic, the upward trend in amphetamine use continued, with post-restriction levels higher than ever recorded.
• In 2021, amphetamine use in the Helsinki metropolitan area declined sharply, most likely as a result of exceptionally large drug seizures by law enforcement authorities (Operation Greenlight).
• Cocaine levels have increased steadily over several years and reached record highs in the most recent measurements in 2025 and 2026. On weekends, cocaine use in the Helsinki metropolitan area now even exceeds that of amphetamine.
• Use of alpha-PVP has increased significantly in recent years.

Increased levels of alpha-PVP in wastewater

Alongside more established drugs, use of alpha‑PVP, the most commonly used novel psychoactive substance in Finland, has increased markedly in recent years according to wastewater data. Levels remained historically high in 2025 and early 2026, particularly in the Helsinki metropolitan area. The rise in alpha‑PVP use is also reflected in studies related to suspected drug‑impaired driving.

In addition, increased use of related synthetic cathinones, alpha‑PHP and alpha‑PiHP, was observed particularly between 2021 and 2024. In 2025 and early 2026, however, their use appears very limited, at least in large cities.

Current scientific evidence does not allow reliable estimation of the amounts of alpha‑PVP used based solely on wastewater residues. Nevertheless, in the Helsinki metropolitan area, alpha‑PVP use is substantial when compared with amphetamine, particularly when considering injecting drug use.
Syringe residue analysis study (ESCAPE)

In 2024, alpha‑PVP use was especially concentrated in southern and south‑western Finland (Figure 7). Outside the Helsinki metropolitan area, daily use of synthetic cathinones was detected only in selected cities and their surrounding areas.

Compared with traditional drugs, novel psychoactive substances show markedly greater variation in use over time and across regions. According to wastewater-based evidence, MDPV – a synthetic cathinone prevalent in the early 2010s – has not been detected in Finland in recent years.

Source

Wastewater research: population-level drug use

Update schedule

Charts from the longitudinal monitoring are updated regularly approximately every three months, while more extensive updates are carried out two to three times per year.