Isn’t it weird when you and your best friend get your period at the same time? Weird, but also kind of cool in a weird way? Like you’ve formed some kind of special bond between you.
Or how about when your whole team is on their period? Crazy! There has to be some logic behind it, right? Is it period sync? Is it a coincidence? Who knows!
Well, actually: professionals and researchers know! And now you will too!
Period synchronization is the idea that when women live in close proximity to each other or spend a lot of time together, the timing of their monthly periods will begin to “synchronize” or align.
The first evidence to suggest that period synchronization could be a ‘real thing’ was in 1971 in a paper called the ‘McClintock Study’. This study is named after her Martha McClintockresearcher at Harvard University.
The McClintock study
McClintock began to investigate the matter by looking at it menstrual cycle of a small number of women aged 17-22 who lived in the college dormitories.
He divided the women into two groups: those who were close to each other, such as best friends or roommates, and those who had no connection to a select group of women.
After six months, he found that those who lived within walking distance of each other started their own period 3 to 7 days apart, while those who were not in close proximity started their periods 5 to 15 days apart.
But given the small scale of this study and the fact that it is outdated, are the results still valid or reliable? Well, not really, according to other researchers.
Results of other studies investigating period synchrony
After the McClintock study, the topic quickly gained traction and other researchers began to work.
Here are some of the results:
- 1993: a study showed that 29 same-sex couples had no experience of synchronization.
- 1995: a study showed that pairs of close friends who did not live together did not experience synchronization.
- 2017: the Clue app teamed up with the University of Oxford to analyze 360 pairs of women who were close friends. After 3 cycles, 273 of the couples noticed an even greater difference in their period start date than at the start of the study.
The latest study actually shows the opposite and that period synchronization is not a thing.
However, before you believe that these studies are 100% valid, it is important to note that they were not peer-reviewed by medical experts. This means that the results are not signed off as final.
In other words, more research needs to be done to finally conclude that period synchronization is real. However, as it stands, it is strongly suggested that period synchronization is not real.
A theory of period synchrony
What makes some people believe in period synchronization? Why does it actually happen?
Well, there is a theory that suggests that if you synchronize period is real, it has to do with the release of pheromones when women are in close proximity to each other.
Pheromones are chemicals that, when released, influence the behavior of others.
But this theory doesn’t really hold much value today because of modern habits.
“Pheromones are largely emitted from the armpits and groin, but consider the habits of modern society. “Maybe there’s something there, but if you wash it all off when you shower, the pheromones won’t have much of an effect.” according Dr. Stazia Tzaveriobstetrician gynecologist.
Period Synchronization: Is It Just a Matter of Time and Math?
So far, we have not found reliable data to prove that period synchronization is real. In fact, many studies show that it is not.
But is there a possible explanation for why you might feel like your period is in sync with your friends or roommates? Actually. And it’s all about timing and math.
You see, over time, a woman who has a 3-week cycle and another who has a 5-week cycle will eventually see their periods overlap.
It’s anecdotal that you’re likely to remember the times you had bad cramps at the same time your roommate did more than the times you didn’t,” says Dr. Jhaveri. “You will overlap and diverge because women have different cycle lengths.”
That makes sense.
And so, because there isn’t enough evidence to prove that cycle timing is real, what are some factors that actually I am doing does it affect your period?
Factors that affect your period
- Taking the birth control pill: when you are at contraceptive pillit changes the levels of sex hormones in your body, which, in turn, can control whether or when you get your period.
- Extreme stress: if you are extremely stressed, your body will release the stress hormone called cortisol. When you have high cortisol levels, it could stop ovulation in its wake, affecting if and when you get your period.
- Chronic disease: a number of chronic diseases such as Diabetescystic fibrosis, kidney disease, and inflammatory bowel disease can affect one’s menstrual cycle.
- Anorexia/Bulimia: successive Purging and binging can make your period irregular or even stop altogether.
- Excercise: if you exercise too much, it could cause you to miss your period or stop it altogether due to the change in hormones that extreme exercise can bring.
So, while the idea behind period synchronization is pretty cute, truth be told, it’s impossible to prove that it actually happens. In fact, there are more studies that say it doesn’t than studies that say it does.
Certainly, more research could be done on the subject. But for now, sorry ladies: period sync isn’t real. It’s just a myth that could be fun to believe.
And hey, you’re not hurting anyone if you find comfort in having your period at the same time as your bestie!