Background: The nutraceutical market is a multi-billion dollar industry. Studies show many cancer patients turn to vitamins and nutraceutical supplements, seeking health improvements post-diagnosis. Despite their popularity, the efficacy & safety of most substances remains unverified through clinical trials. Additionally, interaction with cancer treatments could potentially increase toxicities or diminish chemotherapy effects. In response, our Cancer Center initiated a comprehensive program aimed at enhancing informed decision-making. This involved conducting surveys to understand patient’s attitudes, knowledge, and perceptions about supplement use, alongside evaluating the impact of an educational intervention designed to encourage the discontinuation of self-prescribed vitamins and supplements during cancer treatment. Methods: We utilized a structured survey with open-closed-ended questions to assess dietary supplement use among cancer patients. The survey featured multiple-choice and 1-5 Likert scale questions covering supplement types (e.g., vitamins, minerals, herbs), reasons for use, duration, and timing of use, and beliefs about safety & efficacy. Clinicians also reviewed disclosed non-prescription supplements, advising on their continuation or cessation. Our goal was to understand patient perspectives on supplement use pre & post-educational intervention, among new patients undergoing oral or systemic cancer treatment. We analyzed changes in supplement use with McNemar’s Exact Tests for paired proportions. Results: Following the educational intervention with 144 cancer patients, the proportion not using any supplements rose from 44.4% to 50.0%, hinting at a trend towards discontinuing supplement use. Yet, McNemar’s tests for various supplement categories revealed no statistically significant changes (p>0.05). Of the 73 patients taking supplements and evaluated post-education by a physician, 53.4% were permitted to continue (primarily vitamins), 26% agreed to stop, and 20.5% reaffirmed they would not discontinue use. Of the resistant patients choosing to continue despite medical advice, 93.3% were taking high-dose vitamins, 20% minerals, and 13% herbs/botanical compounds. Conclusions: Supplements are heavily marketed as promoting various anticancer benefits. Our study shows the challenging nature of modifying cancer patients' perceptions. Despite a modest uptick in stopping, a significant portion persisted supplement use post-education, highlighting entrenched beliefs & attitudes. This emphasizes the importance of ongoing, tailored discussions within oncology care to reduce the risks associated with unsupervised supplement use. Our results advocate for incorporating longer-term educational strategies about supplements, underscoring the critical need for evidence-based guidance in managing their use among cancer patients.