Male Puberty

A group of four boys smiling.

Puberty is a stage of growing up when children’s bodies begin to change into those of young adults. It is the period of sexual maturation where the body develops the ability to reproduce. During puberty, the body grows more quickly than it has since the first year of life. Sometimes the changes associated with puberty can be embarrassing or confusing, but it is important to realize that everyone goes through them. Puberty is a normal process! This article details the changes that males will go through during puberty. For an article about female puberty, please click here. Everyone experiences puberty at different times, and eventually all young males will develop traits of young adults. While these changes are similar for most males, remember that variation is normal and no two people are exactly alike. There is no right or wrong way to look; that is the beauty of the human body!

Most males begin puberty between the ages of 9 and 14, but commonly puberty will begin around 12 years old. When the human body reaches a certain weight (which differs among individuals), the hypothalamus releases gonadotropin-releasing hormone. This hormone signals the pituitary gland to release the two hormones that begin the onset of puberty: leutinizing hormone and follicle-stimulating hormone.7 In males, these hormones stimulate activity in the testes, which start to produce the male sex hormone testosterone and begin spermatogenesis. Spermatogenesis is the process of sperm production.

Physical Changes

During puberty, the body undergoes many physical changes. Because how and when these changes take place varies from person to person, there is no “normal” way of going through puberty. As long as the physical changes are not harmful to a male’s health, he should not be concerned. Some of the more common changes are listed below.

Body Growth

The body grows faster. All people grow at different rates and to different heights; this is largely due to how tall the person’s family members are. Various parts of the body tend to grow more quickly than others, such as the legs and hands, which could lead to a somewhat awkward appearance. The differences eventually even out with the completion of puberty.

A banana protruding out of the zipper part of a pair of jeans.

Penis/Testicle Growth

The testicles and scrotal sac nearly double in size during puberty.  As the testicles grow, the skin of the scrotum darkens, enlarges, thins, hangs down lower from the body and becomes dotted with tiny bumps, which are hair follicles. In most males, one testicle (usually the left) hangs lower than the other.1 This is the initial puberty change; penis growth happens later.2

Penis growth tends to be the primary concern for males during puberty. A boy may have adult-size genitals as early as age 13 or as late as 18. In some cases, the penis doesn’t stop growing completely until age 21. First the penis grows in length, then in width. Teenage males seem to spend an inordinate amount of time inspecting their penis and covertly (or overtly) comparing themselves to other males. What most males don’t realize is that sexual function is not dependent on penis size and that the dimensions of the flaccid penis don’t necessarily indicate how large it is when erect.1

Spontaneous Erections

Spontaneous erections are extremely common during puberty. They can happen at unpredictable, unexpected, and inconvenient times, often with no obvious trigger. They are difficult to avoid, but will usually go away within a few minutes. They also become less frequent as males become older.1 Some males also experience nocturnal penile tumescence, also known as “morning wood.” Morning wood is a spontaneous erection of the penis during sleep or when waking up and is common in men of all ages. Morning wood is a remnant of REM sleep cycles and is perfectly normal.

Nocturnal Emissions (“Wet Dreams”)

A nocturnal emission is when a male ejaculates while asleep. Usually, a wet dream happens while dreaming about sex. A male does not have to masturbate to have a wet dream; ejaculation can occur without touching the penis. When the male body starts to produce more of the male hormone testosterone during puberty, sperm production begins. Semen can build up inside the body, and one way it is released is through a wet dream. Wet dreams are a very normal and natural part of growing up. Some males may have a few per week, while others only experience them a few times in their life. Additionally, not every teenager has wet dreams. Frequency of wet dreams may decrease when semen is released in other ways, such as masturbation or sex with a partner.5


Boys are considered capable of procreation upon their first ejaculation, which occurs about one year after the testicles begin to enlarge. Although males experience erections throughout childhood, they do not usually ejaculate until about a year after puberty begins. The testicles now produce sperm in addition to testosterone, while the prostate, the two seminal vesicles and another pair of glands (called Cowper’s glands) secrete fluids that combine with the sperm to form semen. Each ejaculation, amounting to about one teaspoonful of semen, contains 200 million to 500 million sperm.1

A dad and son shaving their beards.

Hair Growth

Body hair, also called androgenic hair, grows longer, thicker, and darker during puberty. Pubic hair begins to develop. A few light-colored soft hairs materialize at the base of the penis. The pubic hair soon turns darker, curlier, and coarser in texture, and grows in a diamond-shaped pattern. Over the next few years it covers the pubic region, then spreads toward the thighs. A thin line of hair also travels up to the navel, sometimes referred to as a “happy trail.” Roughly two years after the appearance of pubic hair, sparse hair begins to sprout on a male’s face, legs, arms and underarms, and later the chest.1

Voice Changes

Just after the peak of the growth spurt, a male’s voice box (larynx) enlarges, as do the vocal cords. For a brief period of time, his voice may crack occasionally as it deepens. Once the larynx reaches adult size, the cracking will stop.1  As a male’s larynx enlarges, so does the laryngeal prominence (called the Adam’s apple) which becomes visible.


During puberty, the skin on the face, neck, back and chest will eventually begin to overproduce a type of oil called sebum. Sebum is a natural, necessary substance — it keeps the skin waterproof and fends off harmful bacteria. However too much is a primary cause of acne. The pubescent skin is also getting rid of dead skin cells at a higher rate, and these skin cells — along with the extra oils — are trying to exit the body by traveling through hair follicles and pores to the surface of the skin. These pores and follicles get clogged up with excess oils and skin cells and the blockage starts building up without anywhere to escape. A form of bacteria known as Propionibacterium acnes gets in the mix and causes the blockage to become inflamed. This pushes it outward, creating the pimple seen on the skin’s surface.3

Breast-like Growth (gynecomastia)

Some boys may also experience growth of glandular tissue of the breasts, leading to a chest with breast-like formations. This is called gynecomastia. This is a temporary development caused by the hormones that are surging through the body, and can be exaggerated by obesity. Gradually, these hormones will subside and the breast-like formations will disappear. This occurs in about 50% of pubescent males and lasts for about 6 months to 2 years.3

Emotional Changes

A group of four boys sitting next to each other outside.

During puberty, most adolescents feel their emotions become stronger and more intense. Although these emotions can make a person feel confused and out of control, it is a completely normal part of growing up. Many teens find that sports, dancing, writing, music, art, or hanging out with friends are good ways to manage stress and feel more in control of their emotions. Changing hormones can cause teens to feel hyper and restless, and finding an outlet (active or creative) is a great way to release excess energy.6

Many adolescents also start having more sexual thoughts and urges. They might develop sexual or romantic attractions to women, men, or both. Some teens masturbate to release sexual feelings and others just wait for the feelings to pass.6

Puberty brings many changes. As a result, most young people have some questions about what’s going on in their body. Many teens find it helpful to talk to someone who has already gone through puberty — a parent, relative, neighbor, or friend. It’s perfectly natural to feel awkward and embarrassed at first, but talking to someone who has already experienced puberty can be a huge relief.

It is so important to remember that everyone experiences puberty! It is a temporary yet crucial part of becoming an adult. Please contact us here with any questions you might have!

Additional Resources
For more information about puberty, check out the following websites:


1. “Physical Development in Boys: What to Expect.” American Academy of Pediatrics, 21 Nov. 2015. Web. 25 Jan. 2016.

2. “Puberty: Adolescent Male.” Johns Hopkins Medicine. The Johns Hopkins University, n.d. Web. 25 January 2016.

3. Tom Scheve. “How Male Puberty Works” 10 March 2009. 25 January 2016.

4. Kaneshiro, Neil K., MD, David Zieve, MD, and Isla Ogilvie, PhD. “Puberty in Boys: MedlinePlus Medical Encyclopedia.” U.S National Library of Medicine. U.S. National Library of Medicine, 20 Nov. 2014. Web. 25 January 2016.

5. Brennan, Dan, MD. “The Facts About Wet Dreams.” WebMD. WebMD, LLC, 22 Dec. 2015. Web. 2 February 2016.

6. “Puberty In Girls and Boys | What Happens During Puberty?” Planned Parenthood. Planned Parenthood Federation of America Inc., 2014. Web. 2 February 2016.

7. Stoppler, Melissa Conrad, MD. “Puberty: Read About the Stages for Boys and Girls.” MedicineNet. MedicineNet Inc., 22 Dec. 2014. Web. 27 Jan. 2016.

Last Updated: 20 February 2016.