Despite the important impact of Heavy Menstrual Bleeding (HMB) in many women’s lives, its management is complex due to the inconvenience of the techniques to assess the real blood loss and the poor correlation between blood loss and women’s perception. A 6 item-questionnaire in Spanish language has been elaborated to address the need to develop an easy-to-handle validated tool to identify HMB cases: the SAMANTA questionnaire. It has shown good sensitivity and specificity to discriminate between women with and without HMB. The main objective of SAMIRA study is to explore, under routine gynaecological practice, if the SAMANTA questionnaire, designed to diagnose HMB, can also be sensitive to change in women with HMB who have been treated for 12 months with a chronic hormonal treatment under therapeutic indication in Spain. This is an observational, prospective and cohort study with a 12 month follow-up that will be carried out in Spain. The sensitivity to change of SAMANTA scale will be explored by estimating the change from baseline to final score in relation to the change in different clinical measurements such as duration of period, blood loss and presence of amenorrhea, and in comparison with patient’s and clinician’s global impressions of severity and change of menstrual bleeding. The SAMIRA study aims to go one step further in order to evaluate whether the SAMANTA questionnaire is also able to detect changes in menstrual blood loss in women with HMB. If the SAMANTA questionnaire shows a consistent behaviour with the rest of clinical measurements, it can be hypothesized that it might be useful for clinicians not only to screen for HMB but also to evaluate the change in HMB severity in patients under a hormonal treatment.