Does the Moon Really Affect Your Period?

These days, we know a lot about our periods. We know that period pain is no joke, how to have an eco-friendly period, and generally what tools we need to make our periods suck less. But for all we do know about periods, there’s still a lot of ambiguity around how the moon’s cycle affects our own cycles. A study by period app Clue pretty much confirms that the moon has very little to do with the menstrual cycle. So if you’re planning a full moon party to kick off the start of your period (okay, that sounds unlikely, but maybe), you might want to reconsider.

The researchers at Clue analyzed 7.5 million cycles of 1.5 million people (so seven cycles per user) who use the app to track their periods and “found no correlation between the lunar phases and the menstrual cycle or period start date.” Well, that clears things up.

“What you normally hear is that you ovulate around the full moon and get your period around the new moon,” said Dr. Marija Vlajic Wheeler, a data scientist at Clue, in a blog postabout the study. “Looking at the data, we saw that period start dates fall randomly throughout the month, regardless of the lunar phase.”

So how did we all get so confused? Legends, myths and language. “The terms ‘menstruation’ and ‘menses’ even come from Latin and Greek words meaning moon (mene) and month (menses). While the data from 1.5 million users of Clue point to no correlation, many people will still find that observing the lunar cycle in relation to their menstruation has meaning for them personally,” the researchers write in the blog post.

Moral of the story: If you feel a meaningful connection between your cycle and the moon’s cycle, by all means, don’t discredit it. But if you’re using the moon to plan for your period, well, we recommend keeping emergency supplies with you at all times.