Menstrual synchrony: Fact or fiction?

Originally Published: June 22, 2001 - Last Updated / Reviewed On: February 20, 2009
Share this

Hey Alice,

Okay, so my mother does not believe, as I do, that when a group of women live closely together (i.e., in a dorm setting) that their menstrual cycles become roughly similar, due to the release of pheromones. I'm pretty sure that I heard this somewhere, but I can't find anything to back it up. I swear I'm not making it up, but my mom doesn't believe me.

Thanks for your help.

—Hopes She's Right

Dear Hopes She's Right,

You and your mother are not the only ones debating the facts surrounding menstrual synchrony (the tendency of women's menstrual cycles to converge). A heavy flow of controversy has existed ever since researcher Martha McClintock first reported the phenomenon in 1971 based on a study published in the scientific publication, Nature, that she conducted in a women's residence hall.

Some scientists claim that women who live together and/or have close emotional bonds (e.g., sisters, mothers and daughters, lovers) have periods that eventually start to coincide or overlap. Other studies have found no evidence of menstrual synchrony in these same groups. Because no research has been able to pinpoint the potential cause(s) of synchrony, other factor(s) may influence the timing of women's periods (e.g., stressor levels, sexual activity, ability to sense pheromones), confusing researchers and roommates alike.

Until more is known about the wonders of menstruation, a definitive answer is unlikely. In the meantime, you and your mother can check out McClintocks research or start your own investigation by seeing what happens within your respective group(s) of women.

Alice

July 19, 2007

21278

I am 50 now and was looking for info on menstrual synchrony out of curiosity after it came up in discussion. I spent all my senior school years in a boarding school and at the beginning of each...

I am 50 now and was looking for info on menstrual synchrony out of curiosity after it came up in discussion. I spent all my senior school years in a boarding school and at the beginning of each year your dorm location and dorm mates was posted on the front door of the main Boarding House. The dorms varied in beds from 2 to 8. Without fail around 2nd term (4 months into the year) most or all of us in the dorm had synchronised to within a few days of each other. This happened for 6 years. Without the internet to answer our question why....we simply took it for granted.

Many years later at 39yrs of age and having settled in one place for the first time since school, I experienced it once again when my best friend and I "synchronised". We worked together, practically lived together and supported each other through a bad time ...and we also never questioned it. It remained the same even after my partial hysterectomy ! Although I no longer had the period, my ovaries continued to work. When I moved away after 8 years, we rang each other around that time, just for fun, to check if it was still the same...even as she began IVF!!. It only changed after my ovaries and tubes were removed 12 months later and her IVF programme alter her periods.

Regardless of the medical debate it was happenning 36 years ago. There were 300 girls at my boarding school.....and we all just took it for granted.

April 20, 2007

21232
Dear Alice,

I don't know about scientific research, but my personal research says yes every time. Whenever I have a girl roommate or spend much time with another girl, our periods always come...

Dear Alice,

I don't know about scientific research, but my personal research says yes every time. Whenever I have a girl roommate or spend much time with another girl, our periods always come together. This never fails. I even had a friend who rarely had regular periods and would often go months without one. When we started living together, it was like clockwork. She would always start the day after me.