BACKGROUND Dietary supplements (DS) are increasingly popular worldwide, with 78% of Polish adults reporting their use, and nearly half using them regularly. The wide availability, selection, and affordability contribute to this prevalence. However, misinformation and potential health risks from incorrect usage highlight the importance of health literacy in making informed choices about DS. This study aims to assess the knowledge and practices related to dietary supplement use among Polish patients. MATERIAL AND METHODS A cross-sectional survey was conducted in 2024 on a representative sample of 1,074 Polish adults, excluding healthcare professionals, using the computer-assisted web interview method. The questionnaire assessed respondents' understanding of DS, sources of information, purchasing habits, and consultations with healthcare professionals. RESULTS Most respondents (71.79%) believed they understood what a dietary supplement is. Women and individuals with higher education were more likely to claim understanding (p=0.001, p<0.00001). The Internet was the most common information source (38.64%), followed by mass media and healthcare professionals. Women and older respondents more often consulted doctors and pharmacists (p=0.002, p=0.004). Brick-and-mortar pharmacies were the preferred purchasing location (61.64%), with men more likely to use online pharmacies (p=0.0002). CONCLUSIONS The study indicates high awareness of dietary supplements among Polish adults, with significant differences based on gender and education. Despite the Internet being a major information source, healthcare professionals remain crucial for informed decision-making. Efforts are needed to enhance public health literacy and ensure safe DS use.