Is It True That Women’s Menstruation Synchronizes?

The idea that women’s menstruation is synchronizing is a popular myth that people have been quoting for the last fifty years. Psychologist, Martha McClintock, first introduced this idea after a study she conducted with women living together in colleges. Her research was even approved by the scientific journal Nature.

Her theory of menstrual synchronization says that when women live together or spend a lot of time together, their menstrual cycles begin to take place at the same time. According to McClintock, her theory was confirmed. Later it was said that pheromones were responsible for the mentioned synchronization.

What are the pheromones that can be responsible for women’s menstruation synchronizing?

Pheromones are a type of hormone that scientists have studied in both rats and other animals. They play an important role in communication and behavior among members of the same species.

In the case of humans, studies have not demonstrated communication via pheromones. We can therefore not conclude that this hormonal mechanism explains the theory that women’s menstruation synchronizes. It is obvious that more studies are needed to be able to confirm or reject the theory of menstrual synchronization.

How is a woman’s menstrual cycle regulated?

At present, there is a lot of knowledge about women’s bodies. It is a subject that science has studied in depth and continues to do.

From the time a woman is born, she has eggs in her ovaries. These remain there without changing until the beginning of puberty. Thanks to the changes that are taking place in this phase, women are entering their fertile phase at that time. From that point on, women experience menstruation every month.

Regulation of these cycles takes place through the effect of stimulators and inhibitors of some hormones in the brain and ovaries. An area of ​​the brain called the hypothalamus periodically releases the hormones involved (LH and FSH). These hormones have a direct effect on the ovaries.

As a result of the release of this hormone, the ovaries respond by releasing a mature egg. At the same time, they release a steroid hormone that is different from those that the hypothalamus releases. The mature egg is ready to be fertilized. And if semen in good quality reaches the egg, then it will turn into a zygote.

During this phase, a thickening of the lining of the uterus – the inner layer of the uterus – also takes place. If the fertilization of the egg took place, then it will settle in the thickened mucosa a few days later. However, if no fertilization takes place, then the mucosa will undergo certain changes which will lead to release.

The entire process described above will generally be repeated every 28 to 35 days. The first day of a woman’s menstruation is day 1. And women can count from this day to be able to determine when they are most fertile, for example.

What do we know about the variation between cycles?

In general  , menstrual cycles have little variation in the age between twenty and forty. In other words, this is the phase with the greatest regularity in terms of dates and monthly repetitions of signs of menstruation.

Before the age of twenty and after the age of forty, women experience greater variation between the cycles. This means that irregular periods are more frequent. Several situations can produce variation in a woman’s cycle in addition to the age itself.

In adolescence, irregularity is common because a woman’s hormonal system has not yet reached full maturity. The same variation occurs in women over forty, and until they reach menopause. In this case, however, it is because their reserves of eggs are running out.

In addition, stress, obesity, low weight, thyroid problems, medications and certain diseases such as diabetes can also produce irregularities. However, the changes may be occasional and apply to a single cycle in particular. However, they can also last for several months.

Does it fit that women’s menstruation synchronizes? The evidence is unconfirmed

In 2006, Anna Ziomkiewicz, an associate professor at Jagiellonian University, concluded that she did not  observe synchronization between women who participated in a study similar to that performed by McClintock. We can say that  there is still a lack of conclusive evidence for the presence of menstrual synchronization  or pheromones in humans.

Many defend the belief that women’s menstruation synchronizes. However, if we look at the current facts, we can only say that the claim is a myth. Perhaps studies in the future will be able to provide greater insight into it and prove it.