Summary Chemsex occurs primarily among gay, bisexual and other men who have sex with men (GBMSM), and there is evidence of a subgroup of users who carry out chemsex-related criminal offences and experience harm. Challenges with chemsex can present to various settings; there are concerns that harm is increasing, including at interfaces between health, social care and criminal justice systems. The UK response to date has lacked a coordinated approach. An expert reference group was convened to share chemsex knowledge, articulate priorities for research and pathway development, and foster collaborative working between agencies. It made three key recommendations: develop and increase training and awareness across all services; implement a coordinated research programme with the development of a common data-set and assessment tool to fully characterise population-level needs; develop a professional network to share information, provide professional support and act as a knowledge hub. There was support for a unified multi-agency strategy incorporating the priorities identified as overarching principles.