Background and methodology: The ovarian cycles of females living and interacting together may synchronise due to pheromones released from axillary secretary glands, the highest concentration of which is produced in the mid-follicular phase, prior to ovulation. The objective of this study was to find evidence for menstrual synchrony in a group of female students living together and to obtain a correlation between the ability to smell the putative pheromone, 5alpha-androst-16-en-3alpha-ol (3alpha-androstenol), found in apocrine secretions and menstrual synchrony. This cross-sectional study involved 88 students who completed a standard questionnaire and whose sense of smell was measured using ten varying thresholds. The menstrual history, friendship scale and menstrual hygiene score was determined for the participants.
Results: A total of 59.1% of the subjects studied were found to have menstrual synchrony. There was no significant association between menstrual synchrony and smelling threshold. However, a significant correlation was found between menstrual synchrony and personal hygiene score (p<0.01).
Conclusions: The phenomenon of menstrual synchrony may be related to various factors. The results failed to demonstrate any significant difference between synchronised and non-synchronised subjects in detecting the steroid by sense of smell. However, the odours associated with menstrual blood or vaginal discharge might have an affect on menstrual synchrony.