Independent report

Response letter from Dame Diana Johnson to the ACMD (accessible)

Updated 20 August 2025

Professor Owen Bowden-Jones,
Chair, Advisory Council on the Misuse of Drugs (ACMD)
Professor Simon Thomas
Chair of the ACMD NPS committee
C/o 1st Floor
Peel Building  
2 Marsham Street  
London  
SW1P 4DF  

By email only ACMD@homeoffice.gov.uk  

20 August 2025

Dear Owen and Simon,

The government’s response to ACMD advice on Semi-synthetic Cannabinoids: Cannabinoids related to tetrahydro-cannabinol and cannabidiol.

I would like to thank the ACMD, particularly the Novel Psychoactive Substances Committee, for diligently monitoring emerging threats, recognising the need to consider these substances, and for providing timely advice. I recognise the significant health and social harms that hexahydrocannabinol (HHC) and other semi-synthetic cannabinoid (SSCs) can have and I am grateful for your advice on how best to reduce those harms and maintain public safety. I have sought views from colleagues in other government departments and my counterparts in the devolved governments where necessary and set out each recommendation and the government’s response below:

Recommendation 1a:

The following compounds should be included as named compounds in the MDA as Class B and in the MDR as Schedule 1 compounds. They should also be listed in Schedule 1 of the Misuse of Drugs (Designation) (England, Wales and Scotland) Order 2015.

Hexahydro-derivatives

• Hexahydrocannabinol (HHC)
• Hexahydrocannabiphorol (HHCP)
• Hexahydrocannabihexol (HHCH) 4
• 9-Hydroxyhexahydrocannabinol (9-OH-HHC)
• 10-Hydroxyhexahydrocannabinol(10-OH-HHC)
• 11-Hydroxyhexahydrocannabinol (11-OH-HHC)
• 10-Hydroxyhexahydrocannabiphorol (10-OH-HHCP)
• Hexahydrocannabinol-C8 (HHC-C8)
• Hexahydrocannabinol-C9 (HHC-C9)

THC derivatives

• 11-Hydroxy tetrahydrocannabinol (11-OH-THC)

THC precursors (cannabinoid acids)

• Tetrahydrocannabinolic acid A (THCA-A)
• Tetrahydrocannabinolic acid B (THCA-B)

I accept this recommendation and will implement it when parliamentary time allows. Prior to that, I intend to consult relevant stakeholders on the two THC precursors (THCA-A and THCA-B) recommended for control under the Misuse of Drugs Act 1971 (the 1971 Act). Given their longstanding status as uncontrolled substances, I consider consultation is appropriate to reduce the risk of unintended consequences for industry.

Recommendation 1b:

Following appropriate consultation, the UK generic text for cannabinoids in the MDA should be updated so that psychoactive SSCs that are not currently captured are included in the MDA as Class B and in the MDR as Schedule 1 compounds. They should also be listed in Schedule 1 of the Misuse of Drugs (Designation) (England, Wales and Scotland) Order 2015.

I accept this recommendation and will consult on amending the UK generic text for cannabinoids in the 1971 Act alongside the consultation on control of two named THC precursors.

Recommendation 2:

More detailed information on the legal status and adverse effects of SSCs should be made available to people who use drugs, the public and staff who may encounter drug users, especially those working in health, and social care.

The public facing websites “Frank” (England), “Know the Score” (Scotland) and “DAN24/7” (Wales) do not appear to include information about these compounds and should be updated to include this, especially for those compounds already prevalent in the UK.

The National Police Chief’s Council has established a cannabis edibles group which provides information to parents. This may be a useful way to pass on information to parents about SSCs, their adverse health effects and their legal status. Information should be provided to schools about the illicit substances that may be found in vapes, their legal status and their potential adverse health effects.

Retailers of vapes and other products that may contain SSCs should be provided with information about their legal status.

Healthcare professionals can register to access comprehensive evidence based online information and clinical management advice about potentially toxic substances, including illicit drugs, via the TOXBASE website, provided by the National Poisons Information Service (NPIS) and funded by the UK Health Security Agency (UKHSA). While TOXBASE provides information about THC, cannabis and SCRA, searches for the SSC described in this report yield negative results. Information about the SSCs described in this report should be included.

I accept this recommendation on behalf of the lead organisations identified by the ACMD, including the Office for Health Improvement and Disparities, which is part of the Department of Health and Social Care (DHSC) and the Devolved Governments. FRANK has already been updated to include information on SSCs and DHSC will work with the relevant government departments, the devolved governments and arms-length bodies to provide the necessary information on SSCs to the public across the whole of the UK.

Recommendation 3:

The status of H4-CBD under the PSA should be established using the standard in vitro testing panel.

I accept this recommendation, and Home Office officials will update the ACMD NPS committee with the results as soon as possible.

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,

Dame Diana Johnson

Minister for Policing and Crime Prevention