If you got your first period before 10 or after 15, your lifelong health story might be more dramatic—and more surprising—than you ever imagined.

At a Glance

• Girls starting periods before 10 or after 15 face higher risks for chronic health issues throughout life
• Early puberty is happening younger than ever worldwide, and the COVID-19 pandemic may have sped things up
• Both early and late puberty impact physical and mental health, from obesity to anxiety and heart disease
• Schools and parents are scrambling to keep up as more children hit puberty earlier than ever

The Childhood Clock is Ticking Faster

Picture this: third graders comparing unicorn backpacks while one quietly panics about bringing a tampon to school. The average age for a girl’s first period has plummeted from 12.5 in the 1950s to just under 12 for those born after 2000. Earlier puberty is not a fluke—it’s a global phenomenon, now affecting over half the world’s girls before they hit double digits. The trend is so pronounced that by age 8, up to 48% of African-American girls and 15% of white girls in the U.S. were showing signs of puberty in the late 1990s. Since then, the clock has only ticked more furiously, with the pandemic adding fuel to the fire.

Why young girls are getting 1st period early?

No, this isn’t just about awkward adolescence. The earlier or later a girl’s period starts, the more her lifelong health script veers off the “average” path. Researchers are now sounding the alarm: starting periods before age 10 or after 15 isn’t just unusual—it’s a flashing red light for future health risks. We’re talking obesity, diabetes, hypertension, heart disease, and even mental health struggles. The plot twist? It’s not only about the body—it’s about the mind, the classroom, and the entire family dynamic.

Start your period before age 10 — or after 15? How it can impact your lifelong health, from obesity to heart issues https://t.co/otCg8OemxE pic.twitter.com/FuMbdjVOlR

— New York Post (@nypost) July 15, 2025

Why the Rush, and Who’s Steering?

Why are girls growing up faster, and who’s behind the wheel? The answer reads like a whodunit with too many suspects: genetics, junk food, body weight, environmental chemicals, and the social upheaval of modern life. Childhood obesity and exposure to so-called endocrine disruptors are under heavy suspicion, but stress and family dynamics are also in the lineup. Lockdowns, increased screen time, and disrupted routines during the pandemic may have turbocharged the trend. Researchers, educators, and public health officials are all clamoring for answers—and for resources to catch kids before they fall through the cracks.

Schools now greet more students dealing with puberty before they’ve even learned what it means, let alone how to cope. Teachers feel ill-equipped, parents blindsided. Health agencies like the CDC and WHO are tracking trends, but the support net is full of holes. The gap between when girls change and when schools talk about it can be years wide. As a result, girls hit not just a biological milestone, but a social and emotional storm—sometimes with no warning at all.

The Lifelong Plot Twists: Health Risks Ahead

Here’s where the story gets more gripping: early or late menarche doesn’t just shape adolescence—it scripts adulthood. Girls who get their periods before age 10 are at higher risk for obesity, diabetes, hypertension, heart disease, and even breast cancer. Their mental health takes a hit, too: anxiety, depression, and social isolation are more common. On the flip side, girls who don’t start until after 15 aren’t off the hook. They face increased odds of irregular periods, certain heart conditions, osteoporosis, fractures, and possibly Alzheimer’s disease. The timing of puberty becomes a lifelong health marker, not just a calendar date.

A landmark 2024 Brazilian study confirmed these risks, analyzing data from more than 7,600 women. The message? Early or late periods are not “just the way it is.” They are signals for doctors, parents, and educators to monitor health more closely and intervene sooner. Yet, most girls don’t get this kind of attention—just a pat on the back and a box of pads.

What Can Families and Schools Do Now?

Don’t panic—prepare. Experts say the best defense is proactive education and health monitoring. Schools should update curricula to match the new biological reality, starting puberty education before fourth grade. Parents should talk openly with daughters (and sons!) about puberty early and often, even if it feels awkward. Doctors should flag very early or late puberty as a reason for more frequent health checks, not just a quirky family trait.

There’s still debate over what’s driving the trend most—food, chemicals, stress, or genetics—but the solution is universal: awareness, support, and early intervention. Everyone from teachers to pediatricians has a role to play in this unfolding story. The earlier we spot the signs and connect the dots, the better the odds for lifelong health—and a less bewildering journey through adolescence.