When Does Puberty Actually Start?

Updated: Sep 11, 2019



Just the word “puberty” is enough to strike fear into the heart of most parents. Not only does it bring on mood swings and irrational behavior, but it also brings on those physical changes that make it impossible for us to deny that our precious babies are growing into young adults.


While most of us probably have some pretty vivid memories surrounding our own trek through puberty, it feels like a completely different story when we’re talking about our kids. Of course we know what puberty is, but many of us have questions surrounding the process like:

  • When does puberty actually start?

  • What are some of the signs puberty has begun?

  • Should I worry if my kid starts puberty earlier or later than their friends?

In HelloJoey’s “Puberty: A Developing Journey” kit, we discuss the average age when the process of puberty begins, along with all the events that lead up to puberty. We also share some of the signs that puberty has started in boys and in girls – and provide information about precocious puberty, delayed puberty, and how to help those early or late bloomers.


When does puberty actually start in boys?

There’s no single event that signifies the beginning of puberty; it’s actually an ongoing process that unfolds in a healthy way over several years. While that process is similar in boys and girls, there are some marked differences in the way puberty unfolds in each sex.


Before puberty begins in boys, their bodies start laying the groundwork with a process called “adrenarche,” and that usually begins somewhere in the six- to eight-year-old range. The adrenal gland on top of each kidney starts making and releasing sex hormones called “androgens,” which are responsible for the development of pubic hair, oily skin, oily hair, and body odor.


While adrenarche creates many of the signs that a child’s body is maturing, it isn’t the maturing of a boy’s reproductive system. That’s puberty – and in boys it typically starts to happen between age nine and 14. This stage of the process is called gonadarche, and it refers to the development of the gonads – or the testicles. Signs that puberty has actually begun in boys include:

  • hair under the arms and on the face

  • a bigger adam’s apple

  • a deeper voice

  • muscle development and growth

  • body odor and acne (from increased oil production)

Finally, boys’ brains send signals to glands in the testicles to begin the process of making sperm, and their bodies become capable of sexual reproduction.


How is puberty different for girls?

Like boys, the puberty process in girls starts with adrenarche between ages six and eight. The brain kicks the pituitary gland into action to release those androgens sex hormones – also kicking off the production of pubic hair, oily skin, oily hair, and body odor.


After adrenarche, our girls also experience gonadarche, when the reproductive glands are activated and the ovaries begin to grow. This is the beginning of puberty, and for most girls, it kicks in sometime between nine and 13. It’s followed by thelarche and pubarche, and signs that girls are in puberty include:

  • enlarging breasts

  • growth and weight gain

  • hair under the arms, on the legs, and in the pubic area

  • body odor and acne (from increased oil production)

Finally, girls reach menarche, when they start menstruation and are capable of sexual reproduction.


App Tip


While puberty usually starts in boys between ages nine and 14 and in girls between ages nine and 13, these are really rough averages. Every child is different, and some kids develop a little earlier, while some go through the process a little later. In many cases, that’s still perfectly healthy – but there are some exceptions.


If actual puberty – the maturing of the reproductive organs – begins early, it’s considered “precocious puberty” or Central Precocious Puberty (CPP). It applies to girls who start puberty before age eight and boys who start puberty before age nine. Early puberty can be hard even for a doctor to diagnose, but precious puberty is estimated to affect about 1 in 5,000 children and primarily happens in girls. If you have any concerns, contact your child’s doctor.



Puberty is considered delayed in boys if the testicles haven’t become enlarged by age 14 or the time between the initial and complete growth of their genitals takes more than five years. Delayed puberty in girls happens when the breasts haven’t developed by age 13 or menstrual periods haven’t started by age 16. This lack of development can lead to bullying or self esteem issues, so kids facing delayed puberty may need some extra support. It’s no reason to panic, but if you’re worried about your child’s development, consult a pediatrician.


Want to learn more about “Puberty: A Developing Journey?”  Start your path to a solid parenting foundation in just 10 minutes a day. Check out the HelloJoey app.

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