Medical or Health Anthropology focused on the study of women continues to be a main area of anthropological study in Spain. The contributions of two referential figures in feminist health anthropology, Marcia Inhorn and Mari Luz Esteban, are applied to review the findings of a qualitative research study on the menstrual cycle carried out through 20 interviews with women between the ages of 16 and 44 years, between 2013 and 2014, in the municipality of Madrid. The analysis shows that menstruation is a clear example of the reproductive essentialization of women, of biological reductionism, of the medicalization of women's bodies and, above all, of the standardization of bodies. The visibilization and questioning of these assumptions through the voices of the women interviewed highlight the importance of this field within medical anthropology.