AbstractBackgroundSelective estrogen receptor modulators, such as tamoxifen, reduce breast cancer risk by up to 50% in women at increased risk for breast cancer. Despite tamoxifen’s well-established efficacy, many studies show that most women are not taking up tamoxifen. This systematic literature review aimed to identify the motivators and barriers to tamoxifen use ‘s amongst high-risk women.MethodsUsing MEDLINE, PsycINFO, and Embase plus reviewing reference lists of relevant articles published between 1995 and 2016, 31 studies (published in 35 articles) were identified, which addressed high-risk women’s decisions about risk-reducing medication to prevent breast cancer and were peer-reviewed primary clinical studies.ResultsA range of factors were identified as motivators of, and barriers to, tamoxifen uptake including: perceived risk, breast-cancer-related anxiety, health professional recommendation, perceived drug effectiveness, concerns about side-effects, knowledge and access to information about side-effects, beliefs about the role of risk-reducing medication, provision of a biomarker, preference for other forms of breast cancer risk reduction, previous treatment experience, concerns about randomization in clinical trial protocols and finally altruism.ConclusionsResults indicate that the decision for high-risk women regarding tamoxifen use or non-use as a risk-reducing medication is not straightforward. Support of women making this decision is essential and needs to encompass the full range of factors, both informational and psychological.