Synchronized menstruation: fact or myth?

Synchronized Menstruation It is a recurring issue in conversations between women. But it can be a controversial subject. Menstruating at the same time or for a period close to a friend's period seems to have great sentimental value.

The coincidence becomes a sign that, in fact, there is a very strong connection between these women; and it is precisely this bond of friendship that would make two friends menstruate together. But does synchronized menstruation really exist or is it just a mathematical coincidence? Know more.

A matter of pheromones

The pheromones They are substances that allow the mutual and sexual recognition of individuals. The excreted pheromones are capable of eliciting specific physiological and / or behavioral reactions in other limbs that are in physical proximity, living in the same environment, for example. This is the case with most animal species, such as rats, whose cycle is synchronized by the fact that females are able to detect pheromones from each other's urine.


In the case of humans, it would take a large amount of pheromones for the women's organism to be able to detect by the smell that another woman is also menstruating.

However, according to an article published in Scientific American, the mechanism for detecting pheromones related to synchronized menstruation is weak in humans.

So far, studies have considered that it would be possible to detect pheromones through sweat, but there are no studies showing that women respond to another woman's pheromones through the odor of sweat.


Mathematical coincidence

Moreover, according to studies, the popular belief in synchronized menstruation would be a coincidence.

That's because women today? who have fewer children and increasingly have access to contraceptive methods? menstruate about 400 times during a lifetime, even considering the periods of pregnancy and the degree of energy spent during breastfeeding and / or exercise.

That number would be enough to create this perception of sync. Furthermore, the article states that considering that a cycle lasts 28 days (not a rule but an example), the maximum time two women can be together without being menstruating is 14 days. On average, there are 7 days. In half of the occurrences, this period is even shorter. Considering that menstruation usually lasts about 5 days, it is not surprising that friends have menstruations in similar periods.

Therefore, it is not a phenomenon resulting from the proximity between friends nor is it related to hormonal issues. It is a coincidence, mathematically speaking.

Do Menstrual Cycles Really Sync Up? (May 2021)


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