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The State of Drug Checking in the United Kingdom

Updated: Jul 24, 2023

UK Drug Checking Options Information Sheet (28/04/2023)

Type of Test



Helpful Tips

Home Reagent Tests

TestsCan identify the likely presence of a drug, and especially whether the drug has been substituted for a different one.

Tests can be ordered online at:, PRO Test (recommended), and Reagent Tests UK (recommended) Available to students at the University of Manchester, Newcastle University, and the University of Bristol, Leeds University, and Cardiff University. Reagent tests are available at some head shops.

Make sure to check for an expiration date. It is better to buy reagent tests that have one. It is better to get a bundle of reagent test kits to test one substance than to test a substance with just one reagent. Liquid forms of Marquis, Mandelin, and Mecke drug reagents cannot be legally carried in the UK without a license.

Home Purity Tests

Can identify the likely purity of a drug if it is only mixed with inactive components.

Tests can be ordered online at and PRO Test (recommended)

These tests will tell you the purity of a sample but they will not tell you the contents of a sample. Another test, such as a reagent test, needs to be used in addition to a purity test to identify the presence of a drug. Just knowing the purity will not tell you the risk level.

Lab Testing

Identifies all the psychoactive components with high accuracy.

Samples are sent in the post to the WEDINOS lab. They accept samples from anywhere in the UK. Results can take up to 2 weeks to be published.

When using WEDINOS, make sure to follow all of the instructions on the website and fill out all sections of the form to ensure that the sample is not rejected.

The above table shows the types of tests available for checking drugs in the UK (Credit to Juliet Flam-Ross)

The First Home Office Licensed Drug Checking Service in the UK

I recently saw the article titled, “Home Office gives green light to first drug testing clinic” in the Guardian and “The UK’s first regular Home Office licensed drug checking service to be set up in Bristol” in Mixmag. The issue is – the articles were written three years apart and about sites set up by two different charities in different locations. It left me wondering which was the real first drug checking service to be licensed by the Home Office in the UK.

Drug checking, sometimes called drug testing, is the testing of unregulated (and often illegal) substances to identify the presence of certain drugs, and sometimes their purity or potency depending on the type of technology.

The first article was written in 2019 about a drug checking service in Somerset, UK run by the charity We Are With You, previously known as Addaction. The second article was written in 2022 about a multi-agency service that plans to open in Bristol, UK funded by the Bristol City Council.

The journalistic flair with which these pieces were written make it sound like all a charity needs to open a drug checking service is approval from the Home Office. I wish this were the case. In a context where drug overdose deaths and other drug-related harms are on the rise, epidemiological evidence-backed harm reduction services including drug checking, drug consumption rooms, and needle exchanges are a crucial priority. In this post, I will describe the state of drug checking services in the UK.

A Note on Terminology

The terminology used to refer to drug checking differs by location. Some people also call it drug testing, drug identification, substance analysis, or other things. I am from the US, where we generally use the term drug checking because the term drug testing often refers to the (frequently involuntary and in a punitive context) screening of others for their drug use. In the UK, urinary drug screening or UDS is generally used to refer to this practice, so the term drug testing does not have the same contextual concerns and is used more frequently here.

Drug Checking in the UK

Reagent Test Kits

Reagent test kits are the most commonly available and easiest to use form of checking drugs in most countries. A common misconception about using reagent tests is that it will waste a large amount of the substance. However, you only need about 3mg of the drug to conduct a reagent test which is not a lot of the drug. For example, if you weigh 70 kgs, a recommended dose of the drug MDMA would be 120mg. A common dose of ketamine would be 30-75mg.

Instructions vary based on the type of kit, but the basic idea is that you mix a small amount of the substance with the reagent, wait for it to turn a certain color, and then use the color chart to identify the likely presence (or lack thereof) of a substance. Often, additional reagents are also used to perform additional indicative tests – in cases where two drugs have the same color with the first test.

There are three main companies that sell reagent test kits to be purchased in the UK:

  1. Reagent Tests UK: This company, based in the UK, has reagent tests (marquis, mandelin, and mecke) that are reformulated to comply with the Offensive Weapons Act of 2019. They also have a YouTube instructional video, a chart to help read the results of the test, and a useful blog that includes drug alerts and photos of different reagent test results.

  2. PRO Test: This company, based in Poland, carries reagent test kits alongside several types of purity tests. They also have a Youtube channel with some helpful instructional videos, a blog and a page where test results can be reported.

  3. This company also carries reagent test kits alongside a blog. An interesting additional item that they carry is a purity test for cocaine, MDMA, and heroin which is also compared to a color chart to indicate potential purity. An important note on this one is that drugs must be tested using reagents first before using a purity test. Otherwise, the purity could indicate the purity of some other drug.

The only test kits that are generally available for purchase in a brick-and-mortar building in the UK are those from which are available in some head shops. They come in glass ampules so they likely have a long shelf life, but because they do not include an expiration date on their kits it is still possible that they could be expired. Unfortunately, there is not a list of stores where these are available. For reagents with transparent expiration dates, kits are available from Reagent Tests UK and PRO Test.

Reagent Tests UK and PRO Test also have tests available for less than £1 per test, whereas sells tests for at least twice that amount and depending on the quantity purchased, it could be more.

In most places outside of the UK, reagents test kits are sold as liquids. However, in 2019 the UK government and European Union both passed laws in response to several high profile acid attacks which made it illegal to carry certain acids without a license. This meant that in order for certain drug reagent kits (Marquis, Mandelin, and Mecke) to be sold in the UK, they had to be reformulated. Two companies reformulated their tests to be compliant with this legislation: Reagent Tests UK and PRO Test.

One test by itself is less indicative than using multiple tests for a substance. There are reagents that will turn the same color for multiple types of substances – meaning that a second test is frequently needed to differentiate. This means that it is generally recommended to buy a test kit for a substance that includes multiple reagents. For example, Reagent Tests UK sells a kit to test MDMA that includes Marquise, Mecke, and Froehde (shown in photo). Both Reagent Tests UK and PRO Test offer kits for different drugs that have multiple recommended reagents.

One of the draws of is that they sometimes sell their kits in head shops, but if you have the time to wait for a kit to come in the mail, the other two companies are generally the most recommended by people who used drugs in the UK for their good price point, transparency on expiration date, support for non-profits like The Loop, and reagent test kit bundles for different substances, and conformity with UK and EU laws.

In addition to head shops, students at some universities in the UK, like the University of Bristol, can get reagent test kits for free.

If you buy your test from Reagent Tests UK, there is an offer on the website to reach out with a photo if there is any uncertainty on the results of a test. However, there is also a popular subreddit r/ReagentTesting where people often post pictures and get feedback on the results of tests. They also have a list of discount codes for reagent test kits.

Finally, if you Google “drug reagent test kits UK”, one of the first hits you are going to get is the 2014 Home Office’s list of approved kits for testing heroin, morphine, amphetamine, MDMA, ketamine, and mephedrone. This list is for the use of law enforcement personnel and the list is outdated but some of the links still work such as this one for a company called Avantor. I do not include these in my list of companies because they are not generally used by people who use drugs. However, in countries where there is not availability of reagent test kits marketed for people who use drugs, reagent test kits marketed for law enforcement may also be an option.

Fentanyl Test Strips

Fentanyl, a synthetic opioid that can be up to 50 times as potent as heroin, can be extremely dangerous. In the US, synthetic opioids like fentanyl accounted for 88% of the 82,000 opioid overdose deaths in 2021. Fentanyl and its analogues are especially dangerous when they are taken by people who are opioid-naive. In some cases, people may take a drug that that they anticipate to be something else but is laced with fentanyl. In the UK, fentanyl and other synthetic opioids are implicated in a much smaller portion of overdose deaths but 16kg of fentanyl and its analogues were seized at the UK border in the year prior to March 2022, indicating that this may be prone to change.

Fentanyl test strips can identify the presence of fentanyl. The substance needs to be dissolved in water and then the test strip should be dipped according to the instructions. The results should appear after the test strip is left on a flat and dry surface. PRO Test has a helpful instructional video on this. It is generally recommended to test the entire sample of the drug because of what is called “the chocolate chip cookie effect”. Because fentanyl is so potent, even a small amount can be fatal and there may be some on one side of the sample but not the other.

Unlike reagent tests, the test strip doesn’t add any contaminant to the sample so the drug can still be consumed even if the entire sample is tested, it just may need to be dried out depending on the intended mode of consumption.

Reagent Tests UK and PRO Test both offer fentanyl test strips for about £1 per test.

Laboratory Testing

Laboratory testing can offer more detailed information on drugs than the results of reagent test kits. There are many different types of laboratory technologies used including infrared spectroscopy (FTIR), high-performance liquid chromatography (HPLC),  paper spray-mass spectrometry (PS-MS), nuclear magnetic resonance (NMR), and gas chromatography-mass spectrometry (GC-MS). Importantly, there are tradeoffs for each of these technologies including cost, time, accuracy, and mobility. But even more importantly, there are several layers of government approval and local permissions that need to be surpassed in order to operate this type of technology as part of a drug service in the UK. 

As I am writing this article, there is only one consistent option to get drugs checked in a laboratory in the UK. This is WEDINOS (Welsh Emerging Drugs and Identification of Novel Substances), which is a laboratory service that began informally in 2009 and formally in 2013. In order to get your drugs checked through WEDINOS, a sample has to be mailed to them with a detailed form. In the process of filling out the form, there’s a button on the website to generate a unique code which is put on the form and then used when the sample is posted online so that it is identifiable. It can take up to 1-2 weeks for the results of the sample to be posted on the webpage after mailing it. The results show both major and minor components that are identified in the sample. Of note, it is important to fill out the form carefully and follow all of the instructions, because there have been reports of samples being rejected for missing a single question on the form

The UK also has a charity which has been offering drug checking at music festivals since 2016, The Loop. In addition to offering the immediate results of a sample, the group also offers individual harm reduction advice based on the results. Regardless of the results of a sample, The Loop’s experts give non-judgmental information about what drugs are present in the sample and the potential effects and interactions of those drugs.

There is also precedent for permanent locations for lab drug checking – sites like this exist in many countries around the world including Europe. The Loop is planning to open the UK’s first permanent drug-checking service this year in 2023 in Bristol.

Secondary Drug Content Sources

If drug checking is not accessible, there is one more option for identifying information about a drug, which is to try to find a place where someone posted information about the same drug online. This is generally only feasible in cases where there is something uniquely identifiable about the drug, such as a pressed pill of a specific color and design. But even then, there could be pills from multiple sources with the same color and design. Here are a few options for trying to do this:

  1. this is an international website where people can post as little or as much information as they want about a drug that they have consumed. They may or may not have checked the substance and reported this information in the post.

  2. The Trip Report: on this Scotland-oriented website, drug warnings on mislabeled or dangerous doses are posted that use combined information from WEDINOS, The Loop, and SaferParty.


Drug checking is available in a limited capacity in the UK. Reagent test kits that test for the presence of drugs are available affordably online and sometimes in stores. Tests for purity are also available online for some drugs. Free lab testing is available by mail in Wales. And last but not least, The Loop is working to open a permanent drug checking site with lab technology in Bristol and then to expand this throughout the UK.


I would like to thank both Josh Torrance and Guy Jones for their significant intellectual contributions and feedback on this piece.


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