Study suggests a mechanism, like the circadian timer that sets the tempo of life, drives the rhythmicity of the 28-day ovarian cycle. After analyzing nearly 27,000 menstrual cycles from 2,300 European women and another 4,800 from 721 North Americans, the authors of the study found evidence that “it is more than likely” that the rhythmic characteristics of the menstrual cycle are explained by an internal mechanism of the body similar to the clock.

If this clock-based process adapts to lengthen the cycle, if it shortens it, then an alteration of this vital rhythm is also associated with dysfunctions in the function of this cycle. In the article they say that there is already "some evidence" that the phases of the cycles can also be under the influence of circadian rhythms and that an altered rhythm is associated with Dysfunctions of menstrual function in Madrid and Barcelona. The study was published this Wednesday in the journal Science Advances, which is published by the University of Lyon.