Wastewater Drug Testing 2021 to 2026: What the Home Office Sewage Data Shows
A Home Office study that tests sewage for traces of illegal drugs has published five years of trend data for England. Ketamine and MDMA estimates have risen sharply since 2021, cocaine is up 17%, and amphetamine and heroin are down by around half. Here is what the figures show, where the patterns differ, and what the data cannot tell you.
In this article
What the study is
On 14 October 2026 the Home Office published Wastewater analysis: estimating drug consumption, 2021 to 2026. The programme samples untreated sewage arriving at treatment works and measures the traces left by drugs after they pass through the body. From that, analysts estimate how much of each drug is being consumed across the population served by each site.
The work is delivered by a consortium of Aqua Clear, Eurofins and Catalytic AI. Its third phase ran from August 2024 to March 2026 in England, and to October 2025 in Scotland, across 52 sites covering about 31% of the population of the two countries. Wales is not included, as the Welsh Government runs its own programme, and cannabis is not measured because of the complexity of sampling it.
The long-term trend figures come from 16 sites in England that have been sampled consistently since 2021, covering about 22% of England’s population. They compare the same January to April sampling window each year.
Five-year trends at a glance
| Drug | 2021 | 2026 | Change 2021–26 | Change 2025–26 |
|---|---|---|---|---|
| Cocaine | 3,206 | 3,743 | +17% | −7% |
| Ketamine | 324 | 953 | +194% | −11% |
| Amphetamine | 2,711 | 1,208 | −55% | −39% |
| Methamphetamine | 149 | 260 | +74% | +8% |
| MDMA | 93 | 325 | +248% | +5% |
| Heroin (experimental) | 1,921 | 989 | −49% | −14% |
Figures are estimated milligrams consumed per 1,000 people per day, January to April sampling windows, 16 English trend sites. Source: Home Office, 14 October 2026.
Cocaine and ketamine
Cocaine has the highest consumption estimate of any drug measured, at 3,743 mg per 1,000 people per day in 2026. That is 17% higher than in 2021, although it fell 7% between 2025 and 2026.
Ketamine shows one of the steepest long-term rises. Its estimate almost tripled, from 324 to 953 mg per 1,000 people per day, an increase of 194% since 2021. Like cocaine, it dipped in the most recent year, falling 11% between 2025 and 2026.
Amphetamine, methamphetamine, MDMA and heroin
Amphetamine moved the other way. Its estimate more than halved, down 55% since 2021, with a 39% fall in the latest year alone.
Methamphetamine remains low in absolute terms but has risen 74% since 2021, including an 8% rise between 2025 and 2026.
MDMA shows the largest percentage increase, up 248% from a low base of 93 mg per 1,000 people per day. The Home Office will no longer test for MDMA in the next phase of the programme.
Heroin estimates are down 49% since 2021. The report labels them experimental and says they should be interpreted with caution: the marker used to detect heroin was found in only 53% of samples.
How the picture varies by region
The phase 3 results, which cover all 52 sites, show clear regional differences:
- Cocaine: higher in the North East, Scotland and one South West site; lower in the East Midlands, Yorkshire and the Humber, and one West Midlands site.
- Ketamine: higher in the East of England, the North West and one North East site.
- Amphetamine: higher in the East of England, the North West and one Yorkshire site.
- Methamphetamine: higher in London, the South East and one Yorkshire site.
- MDMA: higher in the North West, London and one South East site.
- Heroin: higher at one London site, the North East and Scotland.
Estimates tended to be lower in rural areas and smaller cities.
Nitazenes, fentanyl and xylazine
The programme also looked for newer, high-risk substances. Nitazenes — potent synthetic opioids — and fentanyl were rarely detected, and most nitazenes tested for were not found at all. One, 5-aminoisotonitazene, was detected in several regions during two testing cycles, but not every time it was tested for. Isotonitazene was found only in the North West, and xylazine, an animal sedative, only in the South West.
Some prescription medicines that can be misused — gabapentin, pregabalin, temazepam and nordiazepam — were detected in every region.
What the data cannot tell you
The report is clear that consumption estimates do not show the number of people using drugs. A rise could reflect more people using a drug, or the same people using more of it.
The 16 trend sites were chosen for consistent monitoring, not to be nationally representative. Seasonal factors such as summer events and bank holidays, and rainfall affecting wastewater flow, can also affect estimates. A substance not being detected does not necessarily mean it is not being used, as levels may fall below detection limits.
What happens next
A smaller fourth phase began in April 2026. It samples quarterly at the same 16 English trend sites and tracks five drugs: cocaine, ketamine, amphetamine, methamphetamine and heroin. It also tests for the presence of 5-aminoisotonitazene and mephedrone. MDMA, and routine monitoring of the other substances, has been dropped.
Wastewater testing gives an anonymous, community-level view of drug use that surveys and police figures cannot. It cannot identify individuals, and it is not a measure of crime. What it does show is that the mix of drugs consumed in England has shifted since 2021, with ketamine, MDMA and methamphetamine rising, and amphetamine and heroin falling.
The most recent year shows falls in cocaine and ketamine estimates. One year is not enough to call a turning point, and the smaller phase 4 programme will make future comparisons narrower.
If you are worried about your own drug use, or someone else’s, you can get free, confidential information and advice from FRANK, or speak to your GP.
Sources
Frequently asked questions
It is a method of estimating drug use by sampling untreated sewage at treatment works and measuring the traces drugs leave after passing through the body. The results give an estimate of how much of each drug is consumed by the population served by each site.
At the 16 English trend sites, MDMA estimates rose 248%, ketamine 194% and methamphetamine 74% between 2021 and 2026. Cocaine rose 17%.
Amphetamine estimates fell 55% and heroin estimates fell 49% between 2021 and 2026. The heroin figures are experimental and should be interpreted with caution.
No. The report states that consumption estimates do not show the number of people using drugs. They estimate the quantity consumed across the population served by each site.
No. The study covers England and Scotland. Wales runs its own programme, and cannabis is not measured because of the complexity of sampling it.
In the phase 3 results, cocaine estimates were higher in the North East, Scotland and one South West site, and lower in the East Midlands, Yorkshire and the Humber, and one West Midlands site.
Nitazenes were rarely detected and most were not found at all. 5-aminoisotonitazene was detected in several regions during two testing cycles, and isotonitazene only in the North West.
Yes, at a reduced scale. Phase 4 began in April 2026 with quarterly sampling at 16 English sites, tracking cocaine, ketamine, amphetamine, methamphetamine and heroin. MDMA is no longer tested.
Disclaimer: This article is for general information only. Figures are taken from the Home Office report Wastewater analysis: estimating drug consumption, 2021 to 2026, published on GOV.UK on 14 October 2026. Estimates are subject to the limitations set out in the report and do not measure the number of people using drugs. For health advice, contact FRANK or your GP.
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