When does puberty start?

Q: At what age do girls begin puberty? We’ve heard as young as 8! 

A: You’re correct that girls can begin puberty as young as 8 years old. And, in fact, that’s still considered within the range of normal. 

Girls typically start puberty between the ages of 8 and 13.

Boys start between age 9 and 14. 

Keep in mind, however, that puberty is a developmental period that arrives in stages and affects many different parts of the body, including the skeletal, muscular and reproductive systems. 

When people think of puberty, they often think of the more obvious changes seen in the later stages, so it’s understandable they’re surprised it can start at such a young age. 

For girls, the first sign of puberty is a budding of the breasts. About 1 year after puberty starts, girls will go through a peak growth period, in terms of height, weight and muscle mass. Menstruation typically starts 1½ to 2 years after the onset of puberty.

If you’re seeing signs of puberty in a girl younger than 8 or if your girl is older than 13 and hasn’t started showing signs of puberty, discuss this with your pediatrician. 

For boys, the first sign of puberty is an enlargement of the testes, followed by a peak growth period that typically occurs two years after the onset of puberty. 

If a boy shows signs of puberty before age 9, or hasn’t started puberty by age 14 years, discuss this with your pediatrician. 

Kimara Gustafson is a Minneapolis mother who works as a pediatrician at Masonic Children’s Hospital and the Adoption Medicine Clinic, both at the at the University of Minnesota. Send your questions to kgustafson@mnparent.com