This terminology guide has been co-produced with people who have lived and living experience of substance use and engage with Barod’s service user groups. Firstly, we would like to say a huge thank you to everyone that took part in the consultations that resulted in the development and formulation of this document. Much of the content is verbatim of what was discussed within the consultations, by those with lived and living experience. The words and terms listed in this document is not an exhaustive list of the language used when discussing people who use substances, substances themselves and substance use in general. However, many of the words and terms listed was language that people with lived and living experience of substance use deemed most important to highlight and advocate their use or disuse.