With a focus on hormone treatments, this article contributes to recent problematizations of the ontology of bodies, illnesses and medication. Hormone treatment is conventionally understood to comprise preparations like pills, patches or injections, and following from this understanding, the materiality of risk is perceived as potential adverse effects of pharmaceuticals within individual bodies. By discussing Finnish trans persons’ experiences of hormone treatments, and drawing from material feminisms and trans/feminist studies, this article rethinks what ‘hormone treatments’ and their risks materially entail. (...) Stressing the importance of accounting for the relationality of risks, the article suggests that hormone treatment risks can be seen as Baradian ‘phenomena’ that materialize contextually within specific ‘treatment apparatuses’ and the power relations that saturate them. This process of materialization includes the gendering of risks and how the gender binary itself may at times constitute a risk. (shrink)