The changes do not occur overnight. It takes many years for your body to change from a boy to a man fully. On average, these changes take place over an eight to ten-year period. As with the start of the changes, the duration of the changes varies from person to person. Most of your height will be gained during your teenage years. However, it is not usual for men to add another inch or so to their height after they reach 20. As boys approach their teenage years a series of chemicals, called androgens are released into the bloodstream. Androgens are male hormones (female hormones are called estrogens). The main androgen is called testosterone. Testosterone is manufactured in the testicles and is released in the bloodstream in large quantities about a year before you see physical changes in yourself.

The changes do not occur overnight. It takes many years for your body to change from a boy to a man fully. On average, these changes take place over an eight to ten-year period. As with the start of the changes, the duration of the changes varies from person to person. Most of your height will be gained during your teenage years. However, it is not usual for men to add another inch or so to their height after they reach 20. As boys approach their teenage years a series of chemicals, called androgens are released into the bloodstream. Androgens are male hormones (female hormones are called estrogens). The main androgen is called testosterone. Testosterone is manufactured in the testicles and is released in the bloodstream in large quantities about a year before you see physical changes in yourself.