If you’ve ever lived with another female, you’ll be familiar with the idea of monthly, matching mood-swings, copy-cat cravings and house tampon shortages brought on by period syncing, en-masse. For many women, it’s actually a nice thought to know that we’re all united by the power of our biological, menstrual clock. But is this idea actually rooted in scientific fact? Or is the concept of Aunt Flo paying group, female house visits nothing more than an urban legend?
The first period syncing study
The idea of period syncing has its origins in a famous 1971 Harvard study by Martha McClintock. She was the first scientist to suggest that females who engaged in close social interaction with each other for a length of time each day, would experience their periods lining up at similar points each month. Her research also suggested that women who worked or hung out together were more likely to sync up than those who lived together. She suggested that roommates and close friends saw the average number of days between the start of their periods fall from eight or nine to five days and called the phenomena “menstrual synchrony”.
By 1999, a social study found that 80% of women believed in the concept of period syncing, with 70% viewing it favourably. But since the ‘70s, there’s been more research done into disproving McClintock’s popular theory (sorry ladies).
Period syncing isn’t a thing
Despite what we swear we’ve all experienced, a whole lot of investigating lays truth to the idea that actually, period synching is simply urban folklore. A 2006 study of Chinese women living in dorms found that living in groups did not synchronise their cycles. And a review of McClintock’s methods found them to be unreliable as she failed to factor chance into her findings and only surveyed 135 women.
So how do we explain our period syncing?
So, really there is no explanation if you think your menstrual cycle is starting to match your best friend’s. Birth control, stress, coincidence, sickness and anecdotal support are all more likely factors to explain our obsession with period syncing. Maybe our bodies really are listening to each other but at present, it seems there just isn’t the science to support it.
If you’d like to order the contraceptive pill, patch or ring, you can start an online consultation with one of our doctors by visiting our online contraception clinic. If you’d like to delay your period, you can order effective period delay treatment from our online period delay clinic.