On top of everything else, I’m on my period 😩🤬
I text my group chat this announcement once a month.
I send this proclamation “town-crier” style for many reasons. First, because I like to warn my friends when I’m about to bring low vibrational energy to our sacred shared digital space. Second, because there's a chance one of them will feel generous enough to sympathy order me Starbucks. And third because…
*ding*
S: omg same
*ding*
L: omg me too
There’s an extremely high possibility that they too are cramping and bloating — running out the door on an emergency tampon run, scrambling in their laundry hampers for Leakproof Underwear, or just NOW REALIZING why they spent the last week exclusively listening to the "sad girl starter pack" playlist on Spotify? (Okay wait, maybe that last one is just me).
Nothing in this world is more satisfying than when my period syncs up with those around me. There’s a real “we’re in this together” camaraderie that always feels like a huge relief.
Because period-syncing is so tethered to the menstrual zeitgeist, I’ve always assumed period-syncing with those close to you was a proven scientific thing. And I’m not the only one: 70% of period-havers have experienced it, too.
But, much to my surprise, it turns out period-syncing is quite possibly nothing more than a myth. Let me explain.
While period-syncing has been a topic tittered about in friend groups for ages, the scientific community only started paying attention to the phenomenon in the 1970s, thanks to social psychologist Martha McClintok. In 1971, she investigated the "menstrual synchrony" of 135 women living in the same dorm.
After having them track their periods the entire school year, she found that their menstrual cycles tended to sync over time — her theory being that the sync happens through sharing pheromones.
Pheromones are chemical signals secreted by animals, insects, and even some plants which can be detected by their same species, like an invisible language. In humans, they’re believed to play a role in who we find hot, and who finds us hot (among other things).
From McClinktok’s study came a slew of theories as to why pheromones make periods sync. One of them is that it’s an adaptive mechanism that we’ve evolved overtime.
If our cycles are the same, then there’s a higher possibility of getting pregnant at the same time too, which has benefits like increased social support, shared child-care responsibilities in the community, and big ol’ population boosts.
And while that all seems to add up to me, scientists over the last 50 years have been like: wait, hold up just a second there Martha McClinktok. Since she published her findings, her experiment has been recreated in other studies with roomies, couples, animals, and friends with mixed and (often conflicting) results.
On many occasions, they fail to show any kind of syncing at all — including a Chinese study from 2006 that collected period data from 186 students living together in a dorm, as well as research published by Oxford in 2017 that showed periods were actually more likely to step out of sync.
Ready for another BOMBSHELL? On top of all this, the jury is still out as to whether humans even have pheromones in the first place. While it’s probable that human sex pheromones exist because we’re animals, the scientific community remains quite divided.
As it stands, there’s no proof we secrete chemicals that alter the behaviour of other people. (I wonder who’s gonna break the news to the “vabbing” community). So, what the hell do I (and 70% of people) experience? And what was McClinktok talking about in 1971?
It turns out, period-syncing is likely nothing more than a result of… chance and probability.
This all comes down to math?!, I scream into the void. This magical, mysterious phenomenon that fosters community and connection and empathy amongst menstruators is JUST MATH? My worst subject?
Simply put, everyone’s menstrual cycle length is different. Everyone’s bleed time is different, too.
Considering our cycles can last for 15 to 30% of every month, odds are likely that eventually you and your friends match up. Think about it: you’re synced with a lot of people you’ve never even spent time with. It’s just the way it all coincidentally lands on the calendar.
If you’re feeling disappointed that this is all statistics (ugh), I just want to remind you that a question mark lingers. Like most things that deal predominantly with women and non-cis men's health, a lot of this research is still relatively new.
Plus, a lot of these studies are difficult to perform accurately because there are so many factors to consider. There’s still lots of work to be done when it comes to understanding our bodies.
While “math” is currently the most accurate answer for period-syncing, that doesn’t mean it has to stop feeling special when it happens. Commiserating together is still a very important part of the menstruation experience.
At the end of the day, I’ll take a unifying experience in any way I can get it.