OBJECTIVES: Estrogen plus progestin therapies (EPT) represent the current standard of care for postmenopausal women with a uterus for the treatment of symptoms associated with menopause.  While successfully treating climacteric symptoms, the presence of progestin is necessary to prevent endometrial proliferation. Progestins contained in EPT are associated with side effects such as breast pain/tenderness and vaginal spotting/bleeding.  The objective of this study was to conduct qualitative interviews with menopausal women to better understand the patient experience of breast pain and vaginal bleeding symptoms associated with EPT, and the language patients use to describe them, to inform the development of new measurement tools for these symptoms. METHODS:  Fifty-nine postmenopausal women in the USA (n=14), China (n=15), Mexico (n=15) and Italy (n=15) (aged 40-63) taking EPT and experiencing breast pain and/or vaginal bleeding/spotting (47/59 were experiencing both) participated in in-depth interviews concerning their experiences of EPT and impact on quality of life.  Thematic analysis was conducted to identify concepts describing the experiences of the participants using Atlas Ti. RESULTS: In all 4 countries, breast sensations experienced while taking EPT were described as ‘pain and tenderness’, ‘feeling swollen’ and ‘sensitivity’ to touch or contact.  Vaginal bleeding and spotting were commonly described in terms of frequency, volume, colour and consistency.  Frequency of both symptoms ranged from ‘daily’ to ‘occasionally’.  Both symptoms impacted on psychological well-being, activities of daily living and sex life.  Items for new measurement tools were developed using this qualitative data with clinical input from experts in menopause. CONCLUSIONS: In-depth interviews with a geographically diverse sample elicited common descriptors for the symptoms of breast pain and vaginal bleeding and allowed items to be developed that are applicable across cultures, conceptually consistent and easily translated.  Accurately capturing descriptors used by patients is critical to ensure new outcome tools have content validity and cross-cultural reliability.