The Special Link: Lunar and Menstrual Cycles

By Kileigh Ford

Image: Duvet Days

Image: Duvet Days

There’s a  connection between the moon’s cycle and every woman’s menstrual cycle that I’ve heard about for years but never really investigated, so here I am today, finally diving into it for all of us who are secretly hoping it’s true.

The phases of the moon are part of a cycle driven by the amount of light coming around Earth to illuminate the moon. We move from a new moon where you can’t see anything, to a waxing crescent (lit up on the right side), to a first-quarter moon (or half moon), to a waxing gibbous, to a full moon where the entire face is illuminated, to a waning gibbous (where the moon begins  to just be illuminated on the left side), to a third-quarter moon (or half moon), to a waning crescent, then back to a blank, new moon. This cycle takes around thirty days, typically a month, to complete a full cycle.

Similarly, a regular menstrual cycle lasts between twenty-one to thirty-five days. The menstrual cycle moves through phases similar to the phases of the moon. Beginning and ending with the period where your uterus sheds its lining once an egg has not been fertilized, to the follicular phase where an egg begins to mature, to ovulation halfway through your cycle where this egg is released, to the luteal phase, and then back to the menstrual phase of the period.

With similar lengths in time, studies have found a correlation between the likelihood of conception for women during certain phases of the moon. According to Dr. Christiane Northrup, there are peak rates of conception and ovulation on the day of or the day before the full moon. In the same manner, a new moon brings a decrease in ovulation and conception rates, but many women begin their menstrual bleeding. This is attributed  to the moon, light, and the tides’ control over our bodily fluids and subconscious mind. They each play a role in women’s menstrual cycles, fertility cycles, and labor. Dr. Northrup references a study where 1,000 women who had irregular menstrual cycles slept with a light on in an attempt to shift to a regular cycle.

In a separate study conducted in the 1980s, Winnifred B. Cutler found that, out of 312 women who were menstruating, 40% of the women in the study menstruated within two weeks of the full moon. 69 women in the study were noted to have menstrual cycles lasting 29.5 days, the same length as the lunar cycle. One final study, conducted in 1986 by SP. Law, suggested that the relationship between the menstrual and lunar cycles was confirmed by their study of 826 women ages 18 to 25. They found that 28.3% of women experienced their period around the new moon, while the percentages of women experiencing their period at other times only got as high as 12%.

Past the menstrual cycle, studies say that the moon has an influence on other aspects of women’s lives as well, especially in the realms of emotions and sex. Counselor Sioux Rose suggests, in her book Moon Dance: The Feminine Dimensions of Time, that the lunar cycle impacts our emotions. She says the moon, “energizes the collective unconscious” to explain how our feelings are linked to the lunar cycle and, therefore, if we keep note of our emotions day-to-day we will be able to anticipate how we will feel any given day. On the topic of sex, Michael Ra Bouchard, a clinical sexologist, notes in his article, “What Everyone Needs to Know About Women’s Mooncycles”, that women experience moments of heightened  sex drive and times where they want nothing to do with sex. This is typically linked to one’s menstrual cycle and, subsequently, the lunar phases.

The long-standing question has been whether or not the menstrual cycle and lunar cycle are linked, and I can firmly say: yes, they are. Just as the moon has an effect on the tides in our oceans, it has an effect on the fluids in our bodies, influencing women’s menstrual cycles, emotions, and sex drive. The tie between the Earth and the moon is strong, but the connection between humans and the moon is there too. Maybe this means women really are witches… and I’m not mad about that.

Albiges, Marie. “How the Lunar Cycle Affects Women.” The Health Journal, 26 Sept. 2016,
Law, Sung Ping. “The Regulation of Menstrual Cycle and Its Relationship to the Moon.” Acta Obstetricia Et Gynecologica Scandinavica, vol. 65, no. 1, 1986, pp. 45–48., doi:10.3109/00016348609158228.
“Moon: NASA Science.” NASA, NASA,
Northrup, Christiane. “Wisdom of the Menstrual Cycle.” Christiane Northrup, M.D., 19 Jan. 2017,
“Phases of Menstrual Cycle.” Friendly Guide to Healthy Periods - Menstrupedia,
Ra Bouchard, Michael. “What Everyone Needs to Know About Women's Mooncycles.” Sexual Health and Happiness, LLC - Telephone Counseling Worldwide,