Females often find it surprising and strange when their periods sync with either their sister, their roommate, or an office colleague. It leaves them baffled and wondering how that is even possible. They try to look for medical reasons that might prove the reason behind it, but they end up believing that it is some made-up myth and moving on with their lives.

For those who are still wondering how this is possible, you might find some answers here. While period syncing is common, experiencing it everytime you change cities, friends or co-workers can make you question the coincidence of it all.

What is period syncing?

Period syncing is believed to be a phenomenon that occurs when 2 women get their periods at the same time when usually their dates are different. It is based on the theory that when a woman comes in any kind of physical contact with another woman such as spending more time or , their pheromones are influenced and they end up aligning their periods.

The McClintock effect

The idea of periods syncing is old and has been passed down from generation by mothers to their daughters. Period syncing is common for women and girls living in hostels and dormitories. It was all considered a coincidence until a researcher named Martha McClintok decided to conduct a study of 135 women living in a hostel.

She did no consider other factor like the ovulation period and when other women generally menstruated but she did end up concluding that women's periods were indeed, syncing up. Since then the period syncing was known as the “the McClintock effect.”

What does current research say and is period syncing true?

According to a study conducted by the National Institutes of Health, One possible explanation for the periods to be syncing is pheromones, which are chemicals released by the body. These chemicals, especially found in sweat, might affect when a woman's ovulation happens and could even change how long her cycle is.

The more women are around each other, the more likely their cycles may shift because of exposure to each other's pheromones. But not all women showed synchronization. In fact, according to their research 25.8% of the pairs of girls involved the study saw their cycles move further apart. This could be because they were spending more time with other friends.

However, they study also points out that they need more research with larger groups and better methods to fully understand whether this really happens and how pheromones might play a role. So yes, periods syncing is not magical of coinceidental but there is science involved!