Knowledge translation and exchange is the process of increasing the awareness and use of research evidence in policy or practice decision-making. Consumer engagement is a pillar of person-centred care and is crucial in health services research to ensure effective knowledge translation into practice to improve health outcomes. The importance of involving consumers in research endeavours is increasingly being recognized by government and research funding bodies. However, various barriers at the consumer, researcher, and system level often hinder this engagement, particularly in the field of optimizing medicine use and deprescribing, the process of reducing or stopping medicines with more harms than benefits. This chapter aims to guide researchers and clinician-researchers to harness the power of the consumer voice to improve the safe and effective use of medicines and reduce the risk of medicine-related harm. To illustrate this process, we use a research study example. We also explore five key questions: what knowledge should be transferred, to whom, by whom, how, and with what effect, using examples from health services research and deprescribing. Overall, this chapter provides researchers with guidance on involving consumers in their research, specifically in the field of optimizing medicine use and deprescribing.