Is it true that period cycles have a “Bluetooth like effect” where people who live together or spend a lot of time together will have their periods at the same time? I have heard of this phenomenon a few times. Which made me realize, that this has happened to me a few times with friends! Now I am wondering, does this really happen or is it just a mere coincidence?

Great question! “Bluetooth periods” is a term for the phenomenon that when young women live and/or spend a lot of time together and their periods start coming at the same time. The Bluetooth phenomenon has been researched several times, but the results aren’t super reliable. Some relate this to the pheromone effect, often associated with animals. Pheromones are chemicals released by animals that influences the behavior of other animals (of the same species). It’s a great thought, but research has shown that the pheromone effect doesn’t exist in humans. So no, the vagina doesn’t have a Bluetooth connection and neither do periods, it’s simply a coincidence.