A large number of boys experience some breast formation, especially at the start of puberty. It is a normal phenomenon that in the vast majority of cases it is completely innocent. The breast size can be different between left and right. In some situations it takes disfiguring forms and it is easy to understand that boys are ashamed of this.

As puberty progresses, breast growth decreases steadily. The peak of breast formation is between fourteen and fifteen years.


At the start of puberty, relatively much female hormone is still present compared to the male hormone testosterone . This starts the breast formation. When the production of the testosterone increases further, this causes the breast formation to decrease again. This can take several years.

Especially when boys start to worry about it, the size is strongest and the size will decrease afterwards.

It is important to know before a doctor if breast formation occurs at the start of puberty. This can be seen from the size of the testicles, penis and pubic hair.

When breast formation occurs when a boy without that puberty characteristics are is certainly reason to continue searching for the cause. This examination will be carried out by a pediatrician or by a pediatrician specialized in diseases of the hormone system (pediatric democrinologist).

A much rarer cause is breast formation as seen with Klinefelter’s syndrome .

To Investigate

When boys report to their doctor with breast augmentation, they will first want to know when it has started. This is followed by a physical examination, in which in addition to the measurement of weight and height, the stage of puberty development in which the boy is also examined is examined. The latter is important for further assessment. Boys are often very embarrassed about this and it is then necessary for them to be explained why it is important to look at their penis and testicles.

If there is doubt about whether it is the normal form of breast augmentation in boys, blood tests will take place. A number of hormones are being investigated. It concerns the female hormone estradiol, the male hormone testosterone, the stimulating hormone FSH, LH.


The normal breast augmentation that boys often have during puberty needs no treatment, because it is an innocent and transient condition.

When there are many psychological problems due to breast formation, the plastic surgeon can possibly remove the mammary gland tissue.

Frequently Asked Questions

How long does breastfeeding usually take in boys?

Answer: Generally it has been around for two to three years. Then the size drops under the influence of the increased production of the male hormone.

Are fat breasts the same for boys who are overweight?

Answer: No, it is only about stored fat tissue in the breasts. With gynecomastia, it is real mammary gland tissue.

Knowing More

Puberty begins when hormones are produced from the areas in the brain above the pituitary gland, the hypothalamus, which stimulate the pituitary gland to produce two hormones. These are LH and FSH. These hormones stimulate the production of testosterone by stimulating the testicles, among other things. In the beginning, male hormone is only produced at night. During that period the effect of the always present female hormones can be predominant. That causes breast growth.

Later in puberty, testosterone production continues throughout the day, testosterone production increases, and the amount of female hormone is too low to cause breast formation.