As e-health systems are becoming more common and necessary, it is an important field to explore. One important part that has not yet been explored enough is the formation of trust within e-health. An established approach to help formation of trust in other fields is that of user experience design. This Master thesis is focused on the topic of trust formation of first-time e-health service users and how user experience design can influence trust formation. For fulfilling the purpose, the method of think-aloud and semi-structured interviews were chosen. In addition to that, a prototype of an e-health service was developed. The outcome of the interviews was examined through a thematic analysis in order to answer the research questions. Based on the analysis, new aspects which influence trust formation on the surface level were identified, as well as some previously known were confirmed. The themes which are overlapping with previously conducted studies are Design feeling and Element placement. The newly identified themes contain Consistency, Colour and some aspects of Reading experience. The reasons for the identified aspects were categorized into the two themes of Craftsmanship and Expectations. Those findings were compared with previous studies, and recommendations for future research were formulated.