Why is my penis like a baby’s when I am 16?

Last updated on August 4, 2020


Hi! I was wondering, I am 16 and I have only started puberty. My penis is still like a baby’s. Why is this? What should I do?


It can be rough reaching puberty later than most of your friends. Starting at sixteen is still within the normal range, but when it is your body development can’t go fast enough for you.

Whether you start at nine or sixteen, the physical changes will take several years. Puberty officially starts when testosterone, the male hormone, rises in the blood stream, but we generally don’t consider it “real” until physical signs begin to show. The following is roughly the order and time most boys proceed through adolescence:

ChangeFrom the previous changeFrom the start of puberty
Testosterone levels rise00
Testicles begin to increase in size1 year1 year
Thinning of the scrotum, allowing the testicles to hang down. A slight lengthening of the penis. Spontaneous erections begin.3 to 6 months1 1/2 years
Sparse hair at the base of the penis.6 months2 years
Testicles continue to grow. The scrotum is large enough to appear to hang down. Your penis lengthens. Leg and arm hairs grow.6 months2 1/2 years
Ejaculations begin. Pubic hair spreads across the pelvis . Major growth spurt. Voice begins to break6 months3 years
Peak growth rate. Voice deepens. Acne problems show up. Penis continues to grow in both length and width. The glans, at the end of the penis, develops. Scrotum darkens in color. Pubic hair becomes thicker and curly. Hair goes from thigh to thigh.6 months3 1/2 years
Growth slows down and stops. Full adult genitals. Pubic hair spreads to the inside thighs. Facial hair begins.6 months4 years
Muscles begin to increase in mass6 months4 1/2 years

Boys who start later in development tend to develop a little bit faster, but it is still going to take some time. There is nothing you can do to speed up the process. But by the time you reach 21 you will have caught up with most of the other boys. Interestingly, boys who start later in development tend to be slimmer in adulthood than boys who develop early.