Although it is well understood that dehydration can have a major impact on exercise performance and thermoregulatory physiology, the potential for interactions between female sex hormone influences and the impact of dehydration on these variables is poorly understood. Female reproductive hormonal profiles over the course of the menstrual cycle have significant influences on thermoregulatory and volume regulatory physiology. Increased insight into the interactions among dehydration and menstrual cycle hormonal influences may have important implications for safety, nutritional recommendations, as well as optimal mental and physical performance. The purpose of this review is to summarize what is known in this area and highlight the areas that will be important for future work.