Substance-abusing women are vulnerable to specific kinds of epistemic injustice, including stigmatization and discrimination. This article examines the development of the epistemic agency of female substance abusers by asking: How does the use of a formal discussion protocol in community rehabilitation interaction alleviate epistemic injustice and strengthen the epistemic agency of substance abusers? The data were collected in a Finnish rehabilitation center by videotaping six group discussions between social workers, peer support workers, and rehabilitation clients with substance abuse problems. Of these data, one recorded group discussion between four female participants—two rehabilitation clients, a peer support worker, and a social adviser—was used in this paper. Using conversational analysis, the findings indicate that, through the collaborative activities of sharing experiential knowledge about substance abuse and discussing the experiences of abuse in the rehabilitation interaction, substance abusers can develop novel ways to strengthen their epistemic agency by enhanced self-awareness. The discussion protocol is an epistemic tool that professionals and clients can learn to use in ethically and epistemologically successful ways in interaction. The use of a discussion protocol is an example of social professionals’ clinical knowledge of intensifying collaboration and sharing experiential knowledge in community rehabilitation and other substance abuse services.