What’s Behind Early Puberty? New Study Points to Multiple Factors

Puberty in girls has long been linked to estrogen, but new research published in The Journal of Clinical Endocrinology & Metabolism suggests that a broader group of hormones, known as the steroid metabolome, may play a major role in determining when puberty begins. This study, conducted as part of the LEGACY Girls Study, followed 327 girls over six years to better understand how hormones, body weight and stress interact to influence pubertal timing.

“While stress and body mass index (BMI) have long been recognized as independent predictors of puberty, few studies have examined how they interact with a girl’s hormones,” said lead investigator Lauren Houghton, Ph.D., assistant professor of epidemiology at Columbia University Mailman School of Public Health. “Our findings challenge conventional research that has largely focused on estrogen and body size, highlighting instead the role of stress and androgens — typically thought of as male hormones — in shaping pubescent development.”

Investigators analyzed 36 different hormone byproducts (metabolites) found in urine, including those related to glucocorticoids (stress hormones), androgens, progesterone and estrogens. They then compared these hormone patterns with key milestones of puberty, including the onset of breast development (called thelarche), pubic hair growth and the first menstrual period.

“Our objective was to identify the full set of hormonal patterns linked to accelerated puberty and test whether BMI and stress modify this relationship,” said Houghton. “We predicted that girls with elevated BMI and stress would experience the earliest onset — and that the stress response shifts during this key time for girls.”

The findings showed that girls with higher levels of certain hormones before puberty, especially glucocorticoids, androgens and progesterone, were more likely to enter puberty earlier. Among these, progesterone-related metabolites showed the strongest association with earlier breast development.

Importantly, the study also found that BMI and stress significantly influenced this relationship. Girls with higher stress levels and higher BMI, combined with elevated stress hormones, began puberty an average of seven months earlier than those with lower levels. This suggests that emotional and physical health factors may amplify biological signals that trigger puberty.

Investigators noted several important strengths that add confidence to its findings. One key advantage is that it brings together two major areas of research — stress and body weight — to better understand how they jointly influence the timing of puberty. Instead of looking at these factors separately, the team examined them together, offering a more complete picture of what may be driving earlier puberty in girls.

However, the study also has some limitations to consider. There may have been some measurement variability in the hormone testing process, which could slightly affect the precision of the results. While investigators took steps to minimize this, it’s possible the true strength of the associations may actually be stronger than reported. Additionally, although the study used one of the most advanced methods available, it did not measure every possible hormone metabolite, particularly some related to estrogen. Even so, the team included a representative mix of key hormone markers.

Finally, while the study included participants from different racial and ethnic backgrounds, most were White. This means the findings may not fully apply to all populations, and more diverse research is needed to confirm how broadly these results can be generalized.

Overall, the research expands our understanding of puberty beyond estrogen alone. It highlights how a combination of hormonal activity, stress and body composition may contribute to the trend of earlier puberty seen in recent years. For families and clinicians, this underscores the importance of considering the whole child, both physical and emotional health, when discussing development.

“Stress-reducing interventions and healthy lifestyle changes may help delay early puberty and improve long-term health outcomes,” said Houghton. “Because early puberty is linked to increased breast cancer risk later in life, the results have important implications for both pediatric care and public health.”