All together now...

[babybloodheart.livejournal.com]

What is it that results in women whom live together or have close relationships together synchronies with each other's periods?

Comments

[lizdefiance.livejournal.com]

pheromones!

[espression.livejournal.com]

I don't know what it is about the pheromones exactly (we react VERY strongly to them, however - it's said they play a huge part in attraction and even mother-child bonding) but it's interesting to note that some women are "leaders" and some are "followers" when it comes to menstrual cycles. I participated in a grad student's thesis study on the subject and was found to be a "leader" - meaning that most women's cycles will eventually change to follow mine if they're not on hormonal BC. Some women who have irregular periods may just be more susceptible to the pheromones around them - and women like me may have stronger pheromone secretions - according to the student I did the study for.

[allthingsshiny.livejournal.com]

Funny ... the only time I have ever had a regular cycle is when I am living with a woman. I, usually within a couple months, automatically adjust to the other girl's cycle.

[clydiebaby.livejournal.com]

My roommie and I are on the same schedule to the day. It is weird! Nice though, cause we are both psycho on the same days and my hubby only has to deal with it once!

[mactavish.livejournal.com]

There's no real proof that it happens. Some scientists have "proven" it does, but not conclusively. But some people insist it does.

http://www.straightdope.com/classics/a2_306.html