Ultimately, penis growth and its adult shape and size vary widely.
This stage of development occurs during the first six months of life.
The growth of thepenisandtesticlesduring mini-puberty is often predictive of how large they will be in later life.
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Most of the growth happens between the second and third months of life.
Thereafter, the penis will grow more or less in relationship to the boy’s size until puberty.
Other changes can occur in tandem with the increase in penis size.
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Between the ages of 16 and 18, penis growth will slow down and eventually stop as puberty ends.
With that said, some individuals may experience continued growth into their early 20s, albeit minimal.
Why Penis Growth Occurs
In males, penis growth is directed by male sex hormones known asandrogens.
During puberty (and mini-puberty), DHT stimulates growth by attaching to androgen receptors in the penis.
The release of LH and FSH is what ultimately kickstarts the production of testosterone during puberty.
Conversely, delayed puberty tends to correspond to an older age when the penis stops growing.
But, this is not always the case.
After that, the penis isn’t likely to grow all that much longer or thicker.
Likewise, there is no way to accurately predict how large a penis will be after puberty.
The average size of a male penis is often smaller than many people think.
The remaining 5% had an average erect penis length of 3.94 inches (10 cm).
However, some males may continue to experience growth into their early 20s.
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National Institute of Child Health and Human Development.Klinefelter syndrome.
