Do menstrual cycles really sync?

You’ve probably heard the notion that women’s menstrual cycles sync. From biblical times to modern-day college dorms, many people have held onto the belief that their cycles sync with with the cycles of their friends, relatives or people they’re around the most.

But do our cycles really sync? Join our study to find out.

To date, the scientific evidence of cycle syncing is inconclusive, so we want to run the first large-scale study with Clue users. We’ll use our data to determine if friends, roommates, siblings, family members, peers or colleagues really sync. Or if we’re all just victim to cognitive bias.

These are just some of the questions we’re able to answer with Clue’s pool of data to unveil the truth behind popular assumptions. Recently, we ran the numbers to see if the menstrual cycle really syncs with the moon (spoiler: it doesn’t). Read more about our moon study here.

Think your cycle is synced with a friend’s? Want to find out whether cycle syncing really is fact or fiction? Fill out this brief form to join the study. *Please note you must both have Clue accounts to participate.*

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