["Health Expectations, Volume 29, Issue 4, August 2026. ", "\nABSTRACT\n\nIntroduction\nIncorporating the knowledge of people who use/have used drugs into academic research presents the possibility of new ways of understanding drug use, increasing opportunities for equitable outcomes. Community Advisory Boards (CAB) are part of the community‐engaged research continuum offering community members clearly defined roles and a structure to advise academic researchers. Acting in an advisory capacity, CAB members have a platform for sharing community‐informed knowledge with researchers. The concept of knowledge democracy suggests that not all knowledge is valued equally, with scientific knowledge often considered neutral or more valuable than community knowledge which is sometimes understood as subjective opinion. Transformative change requires an embrace of knowledge that extends beyond the sole perspective of academic research to embrace multiple ways of knowing.\n\n\nMethods\nWe used directed content analysis to analyze minutes from 43 monthly CAB meetings, focusing on member knowledge about opioid use and overdose. We centre the expertise of people who use/have used drugs and propose that academic researchers should listen to and embrace knowledge that is held by the communities and people being studied. Aims: (1) identify and describe the knowledge Massachusetts CAB members shared with academic researchers and each other during a federally‐funded study to reduce opioid overdose fatalities and (2) centre the contributions of community knowledge for the study.\n\n\nResults\nThree themes were identified: (1) CAB members generously shared their knowledge; (2) Members brought attention to root causes of opioid overdose fatalities; and (3) Honest and challenging meeting discussions created solidarity and trust among members and with staff.\n\n\nConclusions\nThis case study makes an important contribution to the literature by highlighting the knowledge that a Community Advisory Board, including people with lived and living experience of drug use, can bring to substance use research. By centreing the voices of people with lived and living experience, front line staff, and family members, the study confirms that a substance use research‐focused CAB can be an important source of valuable knowledge, contributing to the development of knowledge democracy.\n\n\nPublic Contribution\nThe HEALing Communities Study Massachusetts Community Advisory Board members ‐ people with lived and living experience with their own or family member drug use, harm reductionists, recovery coaches, and public health advocates committed to saving the lives of people who use drugs – were active participants in the HEALING Communities Study. They were involved in local, statewide and national levels of the study, including community coalitions, study cores, the national steering committee, and dissemination, acting as advisors and consultants with staff throughout the 4 years of the study and beyond. Eighteen months after the study officially ended, members continue to stay in frequent contact with each other and staff and many chose to be co‐authors of this manuscript.\n"]