Despite having some weak correlation in their duration, there is no causal relationship between the lunar cycle and the menstrual cycle. Variability in menstrual cycle length may indicate underlying issues and a common misconception is that the average menstrual cycle is always 28 days.
The onset of puberty is triggered by the removal of suppression of gonadotropin hormone and the activation of cells in the pituitary gland through the release of gonadotropin-releasing hormone. Odors of individuals, both related and non-related, can play a significant role in shaping the neural and hormone systems that trigger or suppress puberty.
Despite having some weak correlation in duration, there is no causal relationship between the lunar cycle and menstrual cycle. However, an erratic cycle ranging from 21 to 35 days long may indicate underlying health issues and should be discussed with an OBGYN.