Chemoprevention with selective estrogen receptor modulators (SERMs) is considered one of the most promising risk reduction options to date in the United States. Tamoxifen and raloxifene are both approved by the U.S. Food and Drug Administration (FDA) for breast cancer risk reduction. However, despite endorsement from the American Society for Clinical Oncology and the National Comprehensive Cancer Network, uptake remains low. Decision aids have been successful in improving women's understanding and knowledge about the risk-benefit trade-offs in decision making regarding SERMs. However, increased knowledge does not lead to increased uptake of chemoprevention for the purpose of reducing breast cancer risk; instead, women become more reluctant to take medication that is itself associated with risks. Reasons for this include a lack of awareness that SERMs are effective in reducing breast cancer risk, an unwillingness to increase the risk of other disease, reluctance to take a daily medication, and the perception of tamoxifen as a "cancer drug." In studies on hypothetical decision making in the context of chemoprevention women indicate greater willingness to take a SERM when they are determined to be at risk. These findings suggest a differential understanding of what risk means among the general public, health professionals, and researchers. Feeling at risk is related to bodily signs and symptoms and not to population-derived probabilities. Such differential understanding may in part explain women's perception of the low efficacy of SERMs and their decision making regarding SERM use.