Women vary in skin color over the course of their menstrual cycle

From mid-cycle on, their skin steadily reddens because of an increase in blood flow that peaks in the day or two preceding menstruation. This cyclical “blushing” mainly affects the torso. Facial skin, especially around the eyes, shows a similar cyclical change. Unlike the torso, the face doesn’t redden towards the end of the cycle. Instead, it becomes browner through increased melanocyte activity.