This essay examines contemporary Tibetan medical literature that deals with menstruation, focusing on the relations among medical, religious and cultural perceptions of women and gender. Present-day medical writers present a hybrid account of menstruation, incorporating key aspects of Tibetan medicine, such as the refining processes of digestion and the red element, with biomedical knowledge, notably die role of hormones. The integration of biomedical thought by Tibetan writers works to substantiate and bolster the validity of Tibetan medical claims, rather than discredit them. Consequently, contemporary writers are able to articulate medical knowledge about women that is as much about Tibetan religious and cultural perceptions of gender and sexed-bodies, as it is 'scientific'.