Results are now available for the fourth quarter (2025) of drugs in wastewater testing, which covers around 77% of New Zealand’s population.

The drugs tested for include methamphetamine, MDMA, cocaine, fentanyl, and heroin. These reports focus on methamphetamine, MDMA and cocaine as these drugs are routinely detected by the programme.

Social harm cost estimates have been included in this report. These are derived from the New Zealand Illicit Drug Harm Index 2023 (National Drug Intelligence Bureau (2023). The New Zealand Illicit Drug Harm Index 2023: Research report. Wellington: Ministry of Health). The Drug Harm Index 2023 provides a conservative measure of the harms associated with the use of illicit drugs in New Zealand and considers both personal and community harms.

Key findings: October – December (Q4 2025)

Please note, the Q4 2025 report includes a third page providing the data behind the per capita consumption by district bar graphs.

Methamphetamine

• Methamphetamine use across sample sites remains elevated and increased in Q4 2025, averaging an estimated 34.7 kilograms per week. This was 8% (or 2.5 kilograms) above the average quantity consumed over the previous four quarters.
• Most districts recorded methamphetamine use similar to or above their respective average consumption over the previous four quarters.
• Methamphetamine use across sample sites in Q4 2025 equates to an estimated weekly social harm cost of $36.4 million.

Methylenedioxymethamphetamine (MDMA)

• MDMA use decreased in Q4 2025, averaging an estimated 6.5 kilograms per week. This was consistent with the average quantity consumed over the previous four quarters.
• Only Bay of Plenty District recorded a notable increase in MDMA use when compared with their average consumption rate over the previous four quarters.
• MDMA use across sample sites in Q4 2025 equates to an estimated weekly social harm cost of $1.4 million.

Cocaine

• Cocaine use continued to increase in Q4 2025, averaging an estimated 9.4 kilograms per week. This was 98% (or 4.7 kilograms) above the average quantity consumed over the previous four quarters.
• All districts recorded cocaine use above their respective average consumption rates over the previous four quarters.
• Cocaine use across sample sites in Q4 2025 equates to an estimated weekly social harm cost of $3.5 million.