Is It True: That Women Who Spend A Lot Of Time Together Have Periods At The Same Time?

Posted on July 30, 2016 in Columns, Is It True, Menstruation, Staff Picks

By Anugraha Hadke:

A few months ago, I was having a rather terrible day in office. Having just started my period, the menstrual cramps were quite nasty. As I sat quietly moping in my favourite corner, a colleague, let’s call her K, came to me with the same mopey face and told me she was ‘floating in the same boat’. Overhearing us, colleague L mentioned that she was on her third day. By lunch, colleague A was complaining about starting her period too.

Since then, we’ve been having our periods at the same time. Many times, we started within a few hours of each other. When one of us starts menstruating, she rings the warning bell so that the rest of us brace ourselves for our turn.

I’m sure quite a few of us have gone through the same. How often have you noticed that your periods happen around the same time as the women around you?

But is there a scientific explanation for this? Do women’s menstrual cycles really get synchronised when they live or spend a lot of time together?

Martha K. McClintock provided some substantiation to the idea of synchronised menstruation in 1971. She conducted a study on a group of girls living together in a college dorm for about 7 months and concluded that “social interaction” does have a strong effect on menstrual synchrony. The study also added that apart from living together, the fact that these women were living in the same environment, eating similar food, drinking similar water, facing similar stress, was also a contributing factor.

Some science folks have also said that pheromones – “chemical air signal” – that we release during this time also contributed to “menstrual synchrony”.

That’s it, right? Science does support it.

BUT (dun dun dunnn). Many others have refuted the McClintock’s findings and criticised her research methods. Jeffrey Schank at the University of California, a colleague of McClintock’s, was part of a study that observed 186 female Chinese students for an entire year – the longest yet. They did not find any evidence of synchrony, just “random overlaps”.

McClintock still stands by her findings though. According to a report by the Scientific American, she says, “[…] given what I know about the causes of menstrual synchrony means I expect it to be rare. So the fact that it is rare doesn’t mean that it doesn’t exist.”

So, do women’s periods really sync up when they spend time together? There might be no concrete answer. We do notice our periods aligning with other women around us, whether that is science or co-incidence. I’m personally inclined to believe that McClintock is right. I’ve mostly been in sync with women from school, college, family and now work. When it happens so many times, it can’t all be a fluke, right?

Let the scientists battle it out. In the meantime, if you do see that your periods have aligned with the women around you, seek comfort in the fact that you are in this together, show your bleeding sisters some solidarity.