For centuries, people have wondered whether the menstrual cycle was linked to the phases of the moon.
One of the first people to suggest a link between menstruation and the moon was none other than Charles Darwin, who observed the link between the length of the menstrual cycle and that of the lunar cycle.
Since then, numerous studies have attempted to draw a conclusion about whether there’s proof of a real connection.
A famous 1986 study claimed that there was in fact a link. After testing 826 women, the researchers found that 28.3 percent of women began their periods “around the new moon.” Another study in 1987 supported this study’s findings.
A 1977 study found that women who began their cycle on the new moon had a greater chance of becoming pregnant.
A 2013 study that analyzed 74 women over 1 calendar year found that there was “no evidence of synchrony.”
Even more recently, a 2021 study suggests that human menstrual cycles may once have been synchronized with the lunar cycle, but that artificial light and modern lifestyles have disrupted that link.
Many Hindu and Buddhist traditions also point to a link between the lunar cycle and menstruation.
According to Ayurveda, blood, or rakta in Sanskrit, is believed to be governed by Chandra, the moon. Women were traditionally believed to be healthier when their cycles were in sync with lunar rhythms.
According to the medieval yogic text known as the Vasishtha Samhita, women were considered to be lunar in nature while men were considered to be solar. It was believed that the lunar cycle affected the various stages of menstruation.