Are the menstrual cycle and the moon connected?
There are two schools of thought around this relationship, one based in science and the other in spirituality. Those things aren’t mutually exclusive, however, so let’s take a look at why we make this connection, and if there’s any evidence to back it up.
Why we connect the moon to the menstrual cycle
The most obvious similarity between the lunar and menstrual cycles is the length. For simplicity, we generalize these cycles as both lasting an even 28 days. (This leads to a lot of misinformation about our bodies, however, as healthy menstrual cycles can be anywhere from 25 to 35 days. Also, the lunar cycle is more precisely 29.5 days long.)
This is likely how we got the words menstruation, menarche, and menses as well. Their origins are from the Latin mensis (meaning “month”) and Greek’s mene and mēn (“moon” and “month”).
There’s also the fact that we are all connected in nature. If the moon can control the tides, and our bodies are ~60% water, it follows that we may be impacted by the lunar phases as well. Correlation does not equal causation, of course, but many of us (menstruators or not) often notice energetic changes that align with the lunar cycle.
The practical view: what the evidence says about periods and the moon
Older studies have linked our cycles with the moon, however, there are conflicting results.
For instance, this 1986 study found that nearly 30% of participants menstruated with the new moon, and this article from 1987 found that their participants most often got their period at around the full moon. This one from 1980 also reports that the women studied menstruated more often near the full moon.
More recent studies dismiss this connection as myth.
My take? We are not machines that can predict or replicate our cycles every month with total precision. If you do menstruate around the new moon or full moon, chances are it hasn’t always been that way for you, and it won’t always be. Since healthy cycles can be anywhere between 25 and 35 days, it’s not always going to be possible to sync up exactly with the moon (though you can get in sync with its energy).
Our modern environment also keeps some people’s cycles from being a perfect 28 days, which makes it more difficult to align with the moon (if it is indeed “supposed” to).
We have so many more chemical variables and stressors impacting our endocrine systems these days, much more so than in decades past. We know how things like stress, illness, medication, diet, and more can impact ovulation and menstruation, and this makes it difficult to really verify how true any of these results are because it’s impossible to control for these variables in a study.
So the evidence is conflicting both in support and against the premise that our cycles are influenced by the moon.
Full moon light and your ovaries
One thing that is known, however, is the association between the moon and ovulation — a connection that needs further research, but is interesting to note.
When it comes to a good night’s sleep, bright light at night can impact melatonin production and make it difficult to get quality rest.
However, it’s been found that mimicking the light of the moon in your bedroom may be helpful for regulating a long cycle. You may be able to improve cycle length by sleeping with curtains open around the full moon or using a night light around ovulation.
Studies show light increases the hormones that trigger ovulation, so in that context it makes sense that people might ovulate with the full moon. This is confusing, however, because light is seen as a major disruptor of sleep quality — see: sleep masks, blackout curtains, stickers that cover the lights from the electronics in your room. It seems there’s an (unknown) threshold. Too much bright light = too low melatonin = disrupted sleep. Just right light = normal melatonin = good sleep.
Long story short: Science says our cycles might be affected by the moon, or they might not. Big help, right?
The spiritual view: what lessons can you learn from the moon?
Research isn’t perfect, as you can see, and it’s often conflicting due to variations in study type and design. But does not having ~official~ confirmation that the moon has an impact on your body change how you work with it?
For me, no. My spiritual practice is very much based in lunar ritual, and I personally do feel very connected to its energy. I don’t need a man in a lab to confirm my relationship with the moon. While my cycle may not always sync up with its phases, I can take what I know about the energy of each phase and apply it to my cycle-syncing self-care.
Culturally, many indigenous groups refer to menstruation as “moon” time. People in the Yurok tribe of California believe that our cycles are dictated by the moon. If ever someone fell out of sync with the lunar body, they’d sit in the moonlight, talk to the moon and ask to become rebalanced.
Ojibwe people believe menstruation is not just a shedding of the uterine lining, but also of negative energy and “accumulated stress.” It’s a renewal process that fellow menstruators gather around and celebrate.
Red moon cycles and white moon cycles
I’m asked a lot about what it means to menstruate around the new or full moon. Health-wise, it means nothing. Spiritually, there is the concept of red and white moon cycles, which suggests a stronger connection to intuition, the earth, and natural cycles.
Truthfully, I have no idea what the origins of this concept are — I couldn’t find a decent source so please comment if you know!
The idea is that if you bleed on the new moon (considered the white moon cycle), you’re in the “mother” phase of your life. What that means is open to interpretation; maybe you’re planning to start a family, you already have kids and are raising them, or you’re experiencing a type of fertility or birth that isn’t physical.
The patriarchy loves this because you’re focusing all your attention outside of yourself. If you identify with this, see how you can take some of that mothering energy for your own personal growth.
A red moon cycle is when you bleed on the full moon. This is also known as the “wise woman’s cycle” because the energy is focused inward to build power. While the white moon cycle is focusing attention outward to share our power with others, the red moon cycle focuses attention inward. It’s a powerful, sensual energy.
This can change, too! You might have a red moon cycle for a while and then slowly shift into a white moon cycle. The most important thing is to track it and follow what’s true for your body. Whichever one you bleed on, think about how you feel. The menstrual phase corresponds to the new moon, so does your personal new moon phase and how you feel at that time match up with the lunar new moon phase?
Maybe you bleed at the full moon; does it feel more in alignment to be more social? Or can you take the qualities of the full moon — the boldness and the authenticity — and apply it to your internal life?
If you feel out of alignment with what’s happening in the sky, that’s okay, it doesn’t have to align, but you can also use the qualities of that time and apply it your cycle phase and see if that feels more natural to you.
Want more of the practical and mystical approach to menstrual health?
Cycle Magic is a cycle-syncing course for menstrual misfits who are tired of recycled wellness advice. It was created for witchy menstruators to take an intuitive approach to nutrition and hormone health for a happier period.