Background The use of dietary and herbal supplements (DIHES) is widespread among people with multiple sclerosis (PwMS). PwMS are a highly informed patient group, and they use several types of sources to seek information on subjects related to their disease. However, it is still unknown where PwMS seek information about DIHES. It is important that PwMS make decisions about DIHES based on accurate, useful and accessible information. Therefore, the aim of this study was to explore where PwMS seek information on DIHES and how they experience and engage with this information. Methods Semi-structured interviews were conducted with eighteen PwMS using DIHES. Participants were selected from a cross-sectional survey. Diversity sampling was used, based on relevant characteristics such as gender and number of DIHES used during the past 12 months. The interviews were conducted face-to-face or over the telephone and lasted between 30 min and 1 hour. The interviews were recorded, transcribed verbatim, and analyzed using thematic network analysis in NVivo 12 Pro software. Results Three main themes emerged in the analysis: i) engaging with healthcare professionals (HCPs) regarding DIHES, ii) social networks as a source of information regarding DIHES, and iii) reliance on bodily sensations. Most participants navigated all three types of sources. All participants had at some point discussed DIHES with an HCP. Information from HCPs was considered reliable and valuable, but HCPs were viewed as uncommitted to the dialogue about DIHES. Recommendations from others were often the driver of decisions regarding use of DIHES. However, the information from PwMS' networks could be overwhelming and difficult to navigate. Finally, PwMS relied on their own experiences regarding DIHES and let their bodily sensations guide their use of DIHES. Conclusions Participants often rely on all three types of information sources to create a nuanced and comprehensive information base. However, PwMS may feel overwhelmed or confused with all the information they have gathered. These findings indicate the need for better guidance for PwMS concerning DIHES and an openness among HCPs to engage in dialogue.