‘Experiential knowledge’ has been identified as a key epistemic resource used by lay people to contest medical authorities and build new knowledge related to health. The Internet has created unprecedented opportunities for such experience-based epistemic projects. This article contributes to understandings of the as yet under-theorised concept of experiential knowledge by analysing accounts of a group of Swedish women who claim that their use of contraceptive copper IUDs has led to systemic side effects not recognised by health care providers. Based on digital group interviews and written essays, we distinguish between three components or stages of experiential knowledge at work in the women’s use of experience as an epistemic resource: somatic knowing, collective validation and self-experimentation. Drawing on a critical realist framework, we defend a notion of experiential knowledge as crucially, while only partially, based on a bodily and practical access to aspects of reality organised by extra-discursive principles. By providing theoretical complexity to the notion of experiential knowledge, we contribute resources for discriminating between and evaluating various experience-based claims, something that is particularly needed in the current ‘post-truth’ era where experience-based knowledge claims pointing in divergent directions flourish.