Research and analysis

The government’s response to the amendment to the Advisory Council on the Misuse of Drugs (ACMD) report on the evidence on the use and harms of xylazine, medetomidine and detomidine (accessible)

Updated 16 January 2026

Professor David Wood
Chair, Advisory Council on the Misuse of Drugs (ACMD)
Professor Simon Thomas
Chair, ACMD New Psychoactive Substances Committee
C/o ACMD Secretariat
1st Floor, Peel Building
2 Marsham Street
London
SW1P 4DF

By e-mail only: ACMD@homeoffice.gov.uk

12 January 2026

Dear Professor Wood

The Government’s response to the amendment to the Advisory Council on the Misuse of Drugs (ACMD) report on the evidence on the use and harms of xylazine, medetomidine and detomidine

As you are aware, following the advice from the ACMD about xylazine, medetomidine and detomidine, published on 16 February 2024, we have controlled xylazine as a Class C drug under the Misuse of Drugs Act 1971 (‘MDA 1971’) and scheduled it under Schedule 4 Part I to the Misuse of Drugs Regulations 2001 (‘MDR 2001’).

I am grateful to the ACMD for your amendment to that report, published on 21 October 2025.  These three substances are dangerous and it is right that we take action to tackle the harms that they can cause.  I have sought views from colleagues in other government departments, other statutory bodies and my counterparts in the devolved governments where necessary, and I set out each recommendation and the Government’s response below:

Recommendation 1

The ACMD’s recommendation

“Although there remains limited evidence of detection and/or harms related to both detomidine and medetomidine in the UK currently, given the reported increase in detection and associated harms in North America and the increasing detections of medetomidine in the UK, similar to xylazine, the ACMD would now recommend that both detomidine and medetomidine are added to Class C of the Misuse of Drugs Act 1971. As both have legitimate use as veterinary medicines, they should be placed in Schedule 4 Part 1 of the Misuse of Drugs Regulations 2001 (as amended).”

The Government’s response

I accept this recommendation and will implement it when parliamentary time allows. 

While I am content that Class C is the correct classification for these drugs, based on the information currently available, I note the report’s conclusion that medetomidine is likely to be around 200 times more potent than xylazine.  I also note the indications of its increasing prevalence in the UK, including the significant recent increase in the number of times when the relevant page on the TOXBASE website was accessed (although there are different possible explanations for that increase).  I would therefore be grateful if the ACMD could keep the situation with medetomidine under review, in case future information were to render a different decision on classification appropriate.

Recommendation 2

The ACMD recommendation

“Information should be provided in an appropriate format to the general public (such as FRANK, DAN 24/7 and ‘Know the Score’) and to harm reduction services on the potential that heroin, fentanyl and other illicit drugs may contain medetomidine and detomidine, and should include the unwanted health effects of these compounds. Users and those coming into contact with them (e.g. emergency department staff, ambulance staff, drug treatment staff), should be aware that the sedative effects of using “drugs” containing both heroin, fentanyl or another opioid and detomidine or medetomidine may not fully respond to use of naloxone, and other supportive measures in the community or in hospital may be required.”

The Government’s response

I accept this recommendation on behalf of the UK Government and the three devolved governments.  All four nations of the UK will work to ensure that appropriate information is made available to the public and healthcare professionals:

• In England, the Office for Health Improvement and Disparities (OHID), which is a part of the Department for Health and Social Care (DHSC), already has information about xylazine on the synthetic opioids page on the Government’s ‘Talk to Frank’ website.  However, OHID is developing a dedicated page on that website for xylazine, medetomidine and detomidine.  The page will contain information on the potential adulteration with these substances - of heroin in most cases, but also of other drugs - as well as their effects and overdose risk.

• The Welsh Government will work with its national helpline DAN 24/7 and partner agencies to ensure the appropriate information is made available to the public and healthcare professionals.

• The Scottish Government will work with partners, including those responsible for delivering the Know The Score website, to ensure appropriate information is made available to the public and healthcare providers.

• The Department of Health in Northern Ireland will work with the Public Health Agency to make appropriate information available to all key stakeholders.

Officials from all four governments will co-ordinate their activities to ensure that these are complementary and not duplicative.

The National Poisons Information Service (NPIS) appreciates the ACMD’s work on xylazine, detomidine and medetomidine.  The NPIS is content that its current advice adequately covers the ACMD recommendations.

Up to date advice on poisoning with all these three substances can be found on TOXBASE.

TOXBASE advice for opioids (e.g., fentanyl and heroin) states that “effects will be potentiated by simultaneous ingestion of alcohol and other sedative drugs (e.g. benzodiazepines, xylazine); reversibility with naloxone will be limited in these situations.”  On the naloxone page, TOXBASE states: “Failure of a definite opioid overdose to respond to large doses of naloxone suggests that another [central nervous system] depressant drug or brain damage is present”.  Detomidine and medetomidine are not specifically mentioned in these pages and adding them along with other possible sedating drugs would not help with management.  It may distract TOXBASE users, who can always call the NPIS if they have further questions or difficulties.

The NPIS will continue to monitor data on exposures to such substances and discuss them at national and international meetings and make further changes as they become necessary.  Members of the NPIS also personally contribute to better outcomes for drug use in their research, education, and administrative roles.

Recommendation 3

ACMD recommendation

“Responsible agencies need to be vigilant and monitor for xylazine and medetomidine, which are being used to augment the UK opioid market, as well as detomidine which has the potential for future misuse.  This can be done by analysis of seized or submitted drug samples, especially seized heroin and other opioid samples, and analysis of patient toxicology and post mortem samples.  Analytical laboratories and services should routinely include medetomidine and detomidine in their screening panels, particularly where opiates have been detected and develop methods for stereoisomer separation of medetomidine to distinguish between licit and illicit use.  These data can then be collected, collated and monitored by the relevant public health agencies in the UK and reviewed by the Office for Health Improvement and Disparities newly established Early Warning System.”

The Government response

I accept this recommendation. Detections of xylazine, medetomidine and detomidine are being monitored in the sources collected or collated by OHID’s Early Warning System which includes forensic testing of seized drugs, post mortem toxicology, drug checking services and the Sentinel drug testing system, run by OHID and the UK Health Security Agency, of biological samples from people starting opioid substitution therapy. OHID will ensure each source is monitored closely for signs of increasing levels of detections of these drugs and will respond appropriately if levels increase, including by notifying the ACMD NPS monitoring committee. Deaths linked to laboratory detections of xylazine-like substances reported to OHID or the NCA are tracked as part of NCA’s Project Housebuilder.  OHID has shared the part of the recommendation for analytical laboratories and services with laboratories in its network.

It is the decision for the coroner in an individual inquest, in discussion with pathologists, as to which drugs which are tested for in post mortem examinations. I have written to the Chief Coroner in England and Wales, the Presiding Coroner in Northern Ireland and the Lord Advocate in Scotland, in her capacity of having oversight of the death investigation activities of the Crown Office and Prosecutor Fiscal Service, to ask if they would be able to share the ACMD’s report with coroners and procurators fiscal and highlight this recommendation to them.

As always, I am grateful for the work of the ACMD in supporting the Government’s aims to protect the public from the harmful consequences of drug misuse and diversion, as part of the wider mission to keep our streets safe. Home Office officials will continue to work closely across government to implement the recommendations agreed in this letter and I look forward to seeing the delivery of these measures in due course.

Yours sincerely

Sarah Jones MP

Minister for Policing and Crime