Ever heard of menstrual synchrony? It's the idea that women who spend a lot of time together (i.e. college dormmates, lesbian couples, roommates) find themselves menstruating at the same time. There have even been a few studies since the 1970s that show that menstrual synchony is possible; but, there have also been studies reputing this claim that "women who go together, flow together." So, what's the answer, really?
The most recent research on the topic actually suggests that any sign of menstrual synchrony is just due to chance - that because of the way women's cycles work, the lining up of periods isn't all that unlikely to just happen naturally, without the influence of close proximity. Women's cycles are often greatly impacted by other external and internal factors, such as stress, medications, genetics, and lifestyle. But, of course, like with all myths, there is a bit of truth in the idea, and that comes from the biological effect of pheromones. Want to learn more about whether you can swing your best girlfriend's period with your pheromones? Watch the video!