Variation in response to experimental pain across the menstrual cycle in women compared with one month respose in men.

Gender differences in pain perception have been reported in literature. However, most such studies have ignored the role of female sex hormones in influencing pain response across menstrual cycle (MC). In this study, we have investigated the variation in pain response on different days of the menstrual cycle. Ninety subjects (60 females) were subjected to experimental pain of cold pressor task, on days 1, 7, 14, and 21 of the MC (females), and on four consecutive Mondays of a month (males). Male subjects showed no variation in pain response. Females reported higher pain sensitivity on days 7 and 14 of MC. We suggest that experimental pain studies involving female menstruating subjects should be carried out only during a particular phase of the cycle, and this phase should be reported in literature to increase the reproducibility of the experiment.