Can the Moon Actually Affect Your Period? Experts Explain

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When I got off the Pill and started tracking my period on my OvaGraph app (just one of many amazing apps that track menses), I started to notice that my cycle was syncing up with the lunar cycle. Specifically, I would often bleed when the new moon would occur. Intrigued, I began researching the connection between the moon and the menstrual cycle to find out if there was any cosmic correlation.

Turns out that, for generations, a woman’s monthly cycle has been linked to the moon’s cycle because they pretty much have the same length, with a typical woman’s menses lasting 28 days and a lunar cycling lasting for about 29.5 days. So was the moon really affecting my period?

“It is believed that when humans spent much of their lives outdoors, they were very influenced by the rhythms of nature,” Dr. Felice Gersh, M.D., OB-GYN and author of PCOS SOS Fertility Fast Track, tells HelloGiggles. “We know that we have evolved to be in sync with our planetary bodies. We women have daily rhythms (our circadian rhythm), lunar rhythms, and seasonal rhythms.”

Exactly how this cycling with the moon developed within our genetics is unclear, though, Dr. Gersh says. “Perhaps the subtle altered gravitational pull that affects the tides also affects our inner clocks and their genetic expression, leading to the development of our lunar rhythm of the menstrual cycle," she says.

These days, however, with fewer outdoor activities and time spent under the sun and the moon, Dr. Gersh says the menstrual cycle is “often irregular” and shows “little to no coordination” with the lunar cycle.

While she cites that one popular study that was published in the American Journal Of Obstetrics And Gynecology in 1980 found some evidence of synchronicity between a woman’s menstrual cycle and the moon, the evidence is a little weak and outdated. Of the sample of 312 women, 244 had cycles that were longer than 29 days or shorter than 27. But only 70 percent of the rest actually started their period within two weeks of the full moon.

However, Dr. Kim Langdon, an Ohio-based M.D. and retired OB-GYN, points out that the study also showed that women with irregular menses tended to ovulate during the dark phase of the lunar period. “The reason was speculated to be because the lunar cycle is associated with the natural rhythm of electromagnetic radiation, which is known to have an effect on the human menstrual cycle.”

For a more holistic—and a little “woo-woo”—approach, Maritza Worthington, CHNC, FDN-P, a GI and hormone specialist and functional nutritionist, says that it’s key to note that, as women, “our feminine cycle ebbs and flows through four main phases, closely mimicking the moon’s cyclical nature. Every month, women experience a powerful metamorphosis as they move through the follicular, ovulation, luteal, and menstrual phases, while the moon also transitions from being full to then waning, new, and waxing in the span of 28 to 30 days.”

Worthington says she often uses the moon as a “powerful” compass with her female clients to deepen their understanding of their own feminine cycle as well as to identify nourishment and cultivate hormonal balance. She does this by encouraging women to moon sync by first identifying whether they are on a "white moon" or "red moon" cycle.

According to Worthington, women who menstruated with the full moon and ovulated during the new moon were regarded as powerful priestesses, healers, and medicine women. This cycle is known as the “red moon” cycle. Women with a “white moon” cycle, on the other hand, were women who menstruated with the new moon and ovulated during the full moon. The “white moon” cycle traditionally represented a woman who wanted to start a family or was focused on nurturing others, as ovulating during a full moon was associated with greater fertility and life. “These two cycle rhythms are still commonly experienced today, yet women who find themselves fluctuating between a 'red moon’ and ‘white moon’ cycle every few months might actually identify with the ‘wise woman cycle,’” says Worthington. “This cycle is considered ‘wise’ because of the breadth of experience this woman has by identifying with both the 'white moon' and ‘red moon’ cycles.”

Although Worthington admits this might sound a little woo-woo and that newer studies need to be conducted for all of this to be truly determined, she cites a 1986 study that points to the “synchronous” relationship that exists between the menstrual cycle and the lunar rhythm in which a "large proportion of menstruations occurred around the new moon (28.3%).”

Keeping in mind that there could be a three- to four-day delay period from the time that the new or full moon begins, Worthington says knowing if you identify with a “white moon” or “red moon” cycle can open the gates to higher intuition and truly understanding your body’s needs.

“I encourage women to tap into this wisdom, because although most women know when they might start their menses (unless there are hormone imbalances), far fewer women are aware of their own ovulation and the three- to five-day fertile window,” she says. “In many cases, knowing if and when ovulation is happening can be such an enlightening piece in balancing hormones, understanding sexuality, connecting with yourself or your partner, supporting fertility, and cultivating overall health. And, in some cases, women might actually discover if they are producing enough progesterone in relation to estrogen or if they need to support their body nutritionally during a certain phase in order to experience fewer period problems and greater energy and prowess.”

While the science might be “soft” when it comes to the moon and menses, Dr. Gersh says there are many studies aligning human behavior with the moon, including one 2010 study that found that the moon influences the human reproduction cycle, linking it with ovulation peaking at the moon’s third quarter.

Even though Dr. Gersh says that the 28-day lunar menstrual cycle can be a rational conclusion to these nature/body connections we sometimes experience, she stresses that we still need hard science to confirm. In the meantime, though, it's okay to lean into the supernatural and track your period with the lunar cycle. You never know—you may discover something about your period you never knew before.