Among the taboos that exist on menstruation, one of the most rooted is to have sex during menstruation, the so-called menstrual sex. The prejudice on men-strual sex has a bio-psychosocial origin, consequently only a 360° analysis of the phenomenon can help to understand and remove the origins of this taboo. Initially the psychological aspects of the woman are considered: how she expe-riences and conceives menstruation and consequently if she practices menstrual sex. Subsequently, the modifications in the hormonal profile, which physical char-acteristics change in her body during the menstrual flow, and how these affect sexual intercourse during those days are examined. The last part offers a discus-sion of how different cultures stigmatize menstruation and menstrual sex and hin-der their practice. There are no contraindications to menstrual sex, indeed there are benefits that increase the psychophysical well-being of the woman, and strengthen the couple’s bond. Alongside the predominant vision of "protection" according to which the woman must conceal menstruation, it is appearing and becoming more emerging the idea of menstrual flow as something more "natural" which as such does not imply changes in the routine of the woman’s life. Therefore, if menstrual blood can be shown shamelessly and all the usual activities can be done in those days, it will also become easy to consider menstrual sex simple and spontaneous. From a broader perspective, it is understood that the elimination of this taboo not only serves to restore naturalness to the phenomenon of menstruation, but it also constitutes an important step towards gender equality. In the future, the hope is that a freer debate will develop, that scientific and psychological research will deepen this area and that taboos and inequalities linked to just being a woman can be overcome.
Keywords: menstruation, sexual behaviour, menstrual sex, taboo, protection, nat-ural.