Fact or fiction? The truth about period syncing
Ever mentioned you’re on your period only to discover that your housemate’s on theirs, too? Or maybe your school friend group always seemed to start bleeding at the same time each month. This curious phenomenon, known as period syncing, is a common experience dating back further than you might think. It’s the idea that when people spend a lot of time together, their menstrual cycles align.
But how much of it is true? We’re delving into the science behind period syncing to attempt to answer this very question. (Spoiler: it’s a bit of a head-scratcher.)
The origins of period syncing: from then to now
There are many reasons that your period may change, but can being close to other menstruating people be one of them?
According to menstrual health expert Dr Andrea Huddleston, the history of period syncing has much to do with the moon.
“This idea of period syncing comes from some stories of traditional cultures where all of the women in the community or tribe would menstruate and ovulate with the full and new moon, and all have their periods at the same time,” Dr Andrea says. “They would often purposefully segregate themselves from the men during their menstrual cycle.
“In many cultures, this was seen as a time of a very deep reverence and a spiritual time for them.”
Indeed, some studies have revealed a potential link between the menstrual cycle and lunar rhythms involving fluctuations in melatonin.
But conflicting studies exist, too. It could be the case that the moon has never affected our cycles. Or perhaps our modern lifestyles have dulled its impact.
“The fact that we have so much artificial light, more stressors in our environment and even hormonal contraceptives changes our pheromones and may, therefore, change synchronicity that possibly could happen,” Dr Andrea says.
Putting the moon aside for a moment, it’s possible that period syncing theories exist through simple coincidence. Periods usually happen every 28 days and last 5-ish days, so the probability of them overlapping with others around you is quite likely.
Scientific research into periods syncing up
Although the concept of periods syncing up has been around for yonks, there isn’t much hard evidence behind its validity.
In 1971, researcher Martha McClintock conducted a study of 135 college students who lived together in a dorm to see if their cycles would align. According to McClintock’s findings, they did.
“The idea was that there’s a pheromonal or chemical interaction that happens with people who live in close quarters,” Dr Andrea says. “Pheromones are the chemicals our body produces that can affect our system.”
However, Dr Andrea says that – based on her experience and available research – the history of menstrual synchrony doesn’t necessarily translate into modern life.
“There have certainly been bigger studies in more modern times that refute this idea of synchronicity of our cycles,” she says. Research from 2006 found that menstrual synchrony happened by chance.
In reality, the evidence we have for period syncing is largely anecdotal.
The verdict: do periods sync?
Based on the scientific evidence at hand, we’d wager that periods do not sync. At least, not for any reason other than coincidence.
One reason theories and studies that support menstrual synchrony (like McClintock’s) don’t cut the mustard is that we’re not sure if pheromones can cause a change in cycle length or timing.
Another reason is that our cycles are unique to the individual: some people’s cycles last for 28 days, while others last up to 40. Some lucky ducks bleed for 2 or 3 days, while others bleed for up to 7. These variations make proper scientific testing tricky.
Still, it’s hard to ignore the abundance of anecdotal evidence behind the phenomenon.
“It is a fairly widespread concept that most people who menstruate believe or experience at some point in their life,” Dr Andrea confirms.
Long story short, more research is needed before we can confidently say that periods do sync.
Manage your flow whenever it shows
Feeling a bit bummed that period syncing may not be real? We get it. There’s something comforting about sharing the menstrual experience with your best pals – especially when periods can give us grief in all sorts of mental and physical ways.
But even if period syncing is just a coincidence, you can still use it as a bonding opportunity. There are plenty of ways to look after each other when we’re bleeding, from making tasty food and filling hot water bottles to simply talking about our symptoms. A pair of absorbent Modibodi period underwear can help provide peace of mind that leaks will stay locked away, so they make a thoughtful gift (for a friend or yourself).
For more period talk, swing by our blog.