With this clinical trial we investigate whether auricular acupuncture during adjuvant endocrine therapy has an improving effect on hot flashes, which are often perceived as psychologically and physically stressful in self-assessment of women with breast cancer. Empirical studies indicate that body acupuncture has positive effects on hot flashes. As auricular acupuncture offers a number of advantages over body acupuncture, a three-armed randomised controlled research design is being used to investigate whether hot flashes caused by endocrine therapy are also reduced by ear acupuncture. Balanced ear acupuncture will be compared with NADA ear acupuncture in terms of efficacy and effectiveness. In addition, the effects of the two forms of therapy on the patients' individual quality of life, fatigue, stress perception and sleep quality will be analysed.