PurposeTo examine patient preferences for oral and intrauterine system treatments for dysmenorrhea in Japan.Patients and methodsA discrete choice experiment was conducted to assess the willingness to accept trade-offs among hypothetical treatment profiles. An internet-based survey was administered to women 18–49 years of age who self-reported a dysmenorrhea diagnosis or experienced dysmenorrhea at least once in the past 6 months (N=309). Choice questions included pairs of treatments presented with different attributes: mode of administration, reduction in bleeding after 6 months, chance of symptoms becoming “improved”, nausea, weight gain, irregular bleeding, and risk of venous thromboembolism. Relative importance (RI) estimates were computed.ResultsThe mean respondent age was 35.8 years (standard deviation =7.0), and 85 women (27.5%) reported that they had previously used hormonal therapy for dysmenorrhea. Treatment preference was most strongly associated with mode of administration (RI=49.8%), followed by chance of irregular bleeding (RI=17.3%). In contrast, treatment preference was most weakly associated with chance of weight gain (RI=2.4%) and reduction in bleeding after 6 months (RI=0.8%). Respondents preferred oral treatments: for twice-daily regimen, odds ratio (OR)=4.90; for once-daily fixed cyclic regimen, OR=4.20; and for once-daily flexible extended regimen, OR=2.44; whereas for intrauterine system, OR=0.02 (p<0.001 for all). Those with prior hormonal therapy experience exhibited the same pattern.ConclusionMode of administration factored heavily in dysmenorrhea treatment preferences. Women of reproductive age preferred oral medication, especially twice-daily regimen and once-daily fixed cyclic regimen. Findings can potentially help to improve physician–patient communication and treatment decision making. Physicians should consider factors that can influence patient preference to optimize treatment acceptance and adherence.