"The Lunar Connection: Circadian Rhythm's Influence on Menstrual Cycles"

A study suggests that menstrual cycle rhythms are likely governed by the body's internal clock, with a weak but significant association with the Moon's orbital period hinting at a more fundamental biology once reliant on the timing of the tides. The research team found evidence of 'phase jumps' in menstrual phases, indicating an adaptation to the body's internal clock. While the study suggests the main mechanism behind menstrual timing is the body's internal clock, there is a weak but statistically significant relationship between menstrual and lunar cycles, which varied depending on geography. The results could lead to potential fertility treatments, and understanding how genes regulate the menstrual cycle is key to understanding its chronobiology.