Why are girls getting their periods earlier and earlier?

A new reality worth understanding

About a century ago, girls' first period occurred on average around 15 years old. In the 1950s and 1960s, this age dropped to 12.5. Today, however, the data shows an even more worrying shift: more and more girls are entering puberty at a much younger age, even from the age of 7. Particularly since the pandemic, evidence of accelerated puberty has intensified, causing intense scientific and social concern.

This trend is not just a biological phenomenon. It reflects the lifestyle, environment, and psychosocial conditions in which children grow up today. A recent large study by the Harvard TH Chan School of Public Health, based on data from tens of thousands of women in the US, showed that the average age of menarche is steadily decreasing in younger generations, while at the same time the time it takes for the menstrual cycle to stabilize is increasing. This finding suggests that the body is being called upon to mature earlier, without necessarily having the conditions for smooth hormonal adjustment.

Precocious puberty matters because puberty is not just a physical change. It is a complex hormonal and psychological process that affects emotional well-being, self-image, and long-term health. Children who mature earlier often experience higher levels of anxiety and depressive symptoms, as they experience physical changes before emotional and cognitive coping mechanisms have developed. At the same time, very early and prolonged exposure to estrogen has been linked to an increased risk of metabolic disorders, obesity, cardiovascular disease, endometriosis, and hormone-dependent cancers later in life.

Behind this change is not a single factor, but a combination of the burdens of modern life. A diet rich in ultra-processed foods, sugar and low-quality fats contributes to childhood obesity and insulin resistance, which have been shown to be powerful accelerators of puberty. At the same time, daily exposure to endocrine-disrupting chemicals, such as those found in plastics, cosmetics, fragrances and personal care products, affects normal hormonal regulation.

The role of excessive screen exposure is also of particular concern. Blue light disrupts circadian rhythms and sleep quality, while reduced physical activity and increased cognitive and social stress further burden the neuroendocrine system. Chronic stress, whether from the family environment, school, or broader social insecurity, is imprinted on children's bodies and affects the rate of their maturation.

While we can’t control all external factors, we can create conditions that support more balanced development. Emphasis on real, unprocessed foods, movement and play in nature, limiting exposure to unnecessary chemicals, good quality sleep, and open, shame-free communication about the body are essential protective measures. Small, daily choices, when repeated consistently, create an environment of safety and stability within which a child can develop at their own natural pace.

Early menstruation is not just a medical issue. It's a message about the way we live and raise our children. And it's worth listening to carefully.

Sources

Wang Z. et al. Menarche and time to cycle regularity among females born between 1950–2005 in the US . JAMA Network Open, 2024.
Harvard TH Chan School of Public Health – Apple Women's Health Study, 2024.
Biro FM, Kiess W. Contemporary trends in onset and completion of puberty . Endocrine Reviews, 2016.
World Health Organisation. Endocrine disrupting chemicals and human health , 2023.
Kaplowitz P. Link between body fat and the timing of puberty . Pediatrics, 2008.
Parent AS et al. The timing of normal puberty and the age limits of sexual precocity . Endocrine Reviews, 2003.