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Sunday, August 9, 2026

Is Period Syncing a Real Phenomenon or Just a Myth?

Is period syncing – where you get your period at the same time as other menstruators in your circle – really a thing? An expert weighs in…

Maybe you’ve experienced it yourself – you, your sisters and your mum all finding yourselves getting your period at the same time and convincing yourselves your period cycles have synchronised.

It’s a widely-believed old wive’s tale that women living in close quarters can find themselves on the same menstrual cycle but is there actually any truth to it?

The answer is no.

“It is a myth,” Dr Mariam Chaalan tells 9honey. “It’s never been proven.”

Dr Chaalan, a GP with a special focus on women’s health, explains period syncing, also known as menstrual synchrony, is “a popular belief that women who live together or spend a lot of time together will end up starting their periods on the same day each month.”

“Like some sort of monthly club where everyone’s in sync, except instead of sharing cocktails, you’re all sharing cramps and cravings,” she jokingly adds. 

“It’s important to note that there’s no scientific evidence to support this phenomenon.”

That’s not to say women and people who menstruate can’t possibly find themselves on the same cycle, but Dr Chaalan says this is simply a coincidence. 

Anecdotally, Dr Chaalan confirms, many women find themselves on the same cycle but its not proven to be a result of living in close quarters and rather just a matter of unique timing. 

Dr Chaalan herself says this is something she’s experienced. 

“It is quite anecdotal. It’s happened to me personally. I lived with three other females growing up and we have very similar cycles as well, so I can appreciate many people have that experience.”

She also says the amount of anecdotal stories may influence a widespread belief in the myth of menstrual syncing. 

“You know, you’re more likely to hear stories about people’s periods syncing than stories of them not,” she say.

While the stories may be convincing, the science says otherwise. 

The whole idea of period syncing came about after a 1970s study by Martha McClintock examined a group of 135 women living in college dorms. McClintock proposed two menstruators in close proximity could synchronise their periods as a result of their pheromones.

After this study, the phenomenon became known as the McClintock effect. 

However, current research doesn’t support McClintock’s theory.

2006 study recreated McClintock’s study collecting the data of 186 women living in dorm in China. This research concluded women do not synchronise their cycles and any period syncing was a matter of coincidence. 

Another study conducted by Oxford University and the period tracking app Clue found that it’s unlikely for women in close proximity of each other to be able to disrupt each others natural cycles. 

Chaalan explains the menstrual cycle is an independent phenomenon influenced by our own unique biology rather than the proximity of other menstruators

This article was reproduced with permission from 9Honey. To read the original article, click here.

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