Group chats are buzzing, parents are anxious and children are confused. Everyone is wondering if girls are really hitting puberty younger than ever? The headlines warn of a crisis, but the truth is more complex than you may realize.
It’s Not Just About Periods
Puberty is not an overnight transformation. It’s more like a rollercoaster of physical and emotional changes that lasts for years. While the conversation often centers on periods, that is only part of the story. Earlier breast development, environment, and socioeconomic status also play a big role in when puberty starts.
A Breakthrough Approach to Studying Puberty
To get a clearer picture of puberty changes in girls, we spoke with Dr. Lauren Houghton, an assistant professor of epidemiology at Columbia University Mailman School of Public Health. Houghton, lead author of a new study published in the Journal of Clinical Endocrinology and Metabolism, and her colleagues examined how stress, body mass index (BMI) and hormones interact in girls. Their approach is a game-changer because scientists have mostly studied obesity and stress in separate lanes. Houghton’s team finally connected the dots.
“Until this study, the research has been pretty siloed,” she told The Root. While researchers have tracked how obesity or stress influenced puberty individually, “no one’s really brought them all together and found a hormonal mechanism.” That is, until now.
The Hormonal Plot Twist
Conversations around puberty hormones usually center around estrogen and progesterone for girls, but Houghton’s team found two different drivers: androgens, the so-called “male” hormones, and glucocorticoids, better known as stress hormones.
Her team discovered that when girls experience both high stress and a higher BMI, it triggers a hormonal change that causes breast development to start about seven months earlier. “Girls that are overweight and stressed have the earliest puberty,” she said.
The Puberty Paradox
Houghton shared that the average age of a first period in the U.S. has remained around 12 since the 1960s, but that number doesn’t tell the whole story. More girls—especially Black girls—are reaching “menarche,” or getting their first period early, according to research, including a 2024 Journal of the American Medical Association (JAMA) study.
Breast development is occurring earlier. According to the Cleveland Clinic, it usually occurs during Stage 2 of the five “Tanner Stages” of puberty, while the first period typically doesn’t arrive until Stages 4 or 5. Houghton’s research shows that the stress-and-BMI “catalyst” is jump-starting Stage 2 earlier, so girls are spending more of their childhood in transition, facing biological shifts long before they are emotionally prepared.
No Simple Answers
There is no one reason for the change in puberty timing. Houghton’s study found that higher levels of androgens and progesterone are linked to both earlier and longer puberty, while some types of estrogen may delay it. This timing is important because breast tissue changes quickly during these years, and the speed of these changes can affect health for many years.
Long-Term Impacts
This shift is especially important for Black families. It is not just about changes in clothing options or hygiene, but also about higher health risks. Houghton says that earlier breast development and a longer time before the first period are linked to higher breast density and a greater risk of breast cancer later in life, since breast tissue is more vulnerable during this fast growth. The Centers for Disease Control and Prevention (CDC) reports that although Black women have a slightly lower overall rate of breast cancer than white women, they are more likely to die from it.
Houghton also said that earlier periods can lead to other long-term health problems, such as heart disease, obesity, and Type 2 diabetes.
What Really Matters
Houghton is adamant that parents should not panic, but notes that the “fix” isn’t just up to individuals. “I think what we need to focus more on are the more structural factors — the social and the environmental factors that would be driving these trends,” she said.
If you are worried about your child’s development, Houghton suggests keeping track of physical changes using the Tanner Stages, which is the system doctors use to monitor puberty. If things seem to be moving too quickly, she recommends asking for a referral to a pediatric endocrinologist, who can look beyond the averages and understand your child’s unique hormonal pattern.
For Black families, who often have to work harder to be heard by doctors, keeping clinical records is a powerful way to advocate for their children. As Houghton said, “You’re going to need some data to convince some other people.”
