Maintaining normal blood glucose levels is a constant challenge for women with diabetes. Anecdotal reports reveal that many women question if menstrual cycle phases may affect their blood glucose levels. However, results from studies investigating the effect of the menstrual cycle on insulin sensitivity in diabetic women have been conflicting. One variable that may account for the conflicting results is the presence or absence of premenstrual syndrome (PMS), which may exacerbate menstrual cycle-related effects on insulin sensitivity. Treatment of PMS with serotonin reuptake inhibitors may alleviate the symptoms of PMS, as well as improve insulin sensitivity and help regulate blood glucose levels.