Dr. Howard Smith Oncall

Vidcast:  https://www.instagram.com/p/C6WyG78rC4H/ A new look at this issue by French and American researchers is dispelling the age-old hypothesis that women’s menstrual cycles are completely controlled by lunar phase cycles since both are roughly 28 days in length.  After studying more than 3,000 young women from both countries and analyzing 27,000 ovarian cycles, they conclude that the cycle lengths are controlled by the body’s internal circadian rhythms.  These same circadian cycles control other functions such as sleep.   In addition to this internal biological cycle clock, the data analysis did point to a correlation between a woman’s cycle initiation and the phases of the moon.  The first day of a woman’s cycle was significantly correlated with the waxing crescent moon phase for European women and with the full moon for American women.. The bottom line: the length of a woman’s cycle is determined by an internal biologic clock with some fluctuations.  Mysteriously, though, cycle onset does have some