Can Your Menstrual Cycle Really Sync With Your Close Friends?

At some point in life, you may find yourself having periods at the same time with your best friend, roommate or sister. There has been a myth going around for quite some time that those women who stay close together have their periods synced up. In college, you will not miss finding two or three girls who sleep in the same room having periods at the same time. They believe that the other girl has shifted her periods to align with the other girl cycle.

Researchers call this menstrual synchrony. A theory that believes when women stay close together and spend most of their time together, they get their periods almost at the same time. It is believed that pheromones or an airborne chemical signal released by an individual into the environment affects the physiology or behavior of other people surrounding them.

This research on menstrual synchrony was done by Martha McClintock in 1971. She studied the cycle of 135 female college students who lived in the same dorm and reported a high synchronization in their menstrual cycle. According to her research, she believes that women do sync up.

Can Women’s Menstrual Cycle Really Sync Up?

Many research studies have been done and some seem to agree with McClintock’s findings while others haven’t found any evidence on menstrual synchrony. A research done in 2006 found that women who are not using birth control have an inconsistent cycle which is difficult to sync up.

The research also found that cycle fluctuation in women leads to repeated menstrual convergence which might bring the perception of synchrony. This will make women believe that their periods have been aligned with their friends’ but this is just a short random series of alignment.

The most recent research which used a period tracker app didn’t find much synchronization in the data collected but agreed that women cycle will converge at some point shortly before they diverge again. Although there is no scientific explanation as to why sometimes your periods matches your friend’s, there exists a mathematical explanation which states that it’s a matter of time before someone who has a three-week cycle and another one with five-week cycle converge in their menstrual cycle. So if you stay with someone for a year, you’re most likely to experience a convergence of menstrual cycle at some point of your stay together.

Researcher Jeffrey Schank reported that since women have different length cycles, it’s hard for them to have synchronized periods. He also noted that women cycle are affected by different factors like birth control methods, stress, weight gain, exercises activity and even nutrition.

So most research studies have found that women’s cycle doesn’t sync up and any time your periods starts at the same time with your friends’, then it’s just by chance or coincidence and nothing like syncing up. Although it’s fun to realize that you are undergoing the same biological process with your closest friend, making you feel that you have a strong bond together.

Factors That Can Affect Your Period Cycle

1. Birth control pills

The hormonal birth control methods can interfere with your menstrual cycle because it alters the levels of progesterone and estrogen hormones in your body.

2. Stress and anxiety

Having too much stress or too much anxiety can delay or bring your periods early.

3. Chronic illness

Chronic diseases that require regular intake of medication can interfere with your period cycle.

4. Too much exercising

Straining too much during workouts can make your periods to come earlier or delay.

5. Food and Environment

Change of climate and food can alter your menstrual cycle. For example, if you visit a foreign place where food and climatic conditions are different, your period’s calendar will surely change.