Drug manufacturer Janssen Pharmaceuticals introduced Invega to the market in 2006. Also known by its generic name paliperidone, Invega is now used as a treatment for the symptoms of schizophrenia.

Unfortunately, the mechanism by which Invega relieves schizophrenia symptoms may also put young male patients at risk for developing breasts.

Patients may not be aware of that possible side effect before deciding to take Invega.

Some patients may not realize Invega causes female-like breasts in boys until after they had developed gynecomastia themselves.

How Invega Causes Female-Like Breasts in Boys

While scientists may not be perfectly certain how Invega causes female-like breasts in boys, they do have a theory.

Atypical antipsychotics like Invega can increase the level of a hormone called prolactin, which can stimulate the growth of breast tissue.

Prolactin occurs in just about all persons’ bodies, both men’s and women’s. Levels of prolactin increase naturally in young women and nursing mothers, stimulating breast tissue growth, milk production, and lactation.

Invega affects patients’ prolactin levels indirectly, by affecting the function of the neurotransmitters dopamine and serotonin. By blocking the receptors that work with these neurotransmitters, Invega stimulates an increase in production of prolactin.

When the level of prolactin is increased artificially in males, it can cause the same increase in breast tissue development that it causes naturally in females.

This increase in prolactin levels is how scientists believe Invega causes female-like breasts in boys.

This abnormal breast development in men and boys is known clinically as gynecomastia.

If its cause is not discovered and discontinued, male patients may even exhibit milk production and lactation, known clinically as galactorrhea.

Gynecomastia typically begins as a lump just beneath the nipple. How large the new breast tissue may grow varies widely among different patients. One breast may grow larger than the other, or gynecomastia may affect one breast without affecting the other at all.

Not only are there concerns Invega causes female-like breasts in boys, Invega can also cause weight gain, and the associated increase in fat tissue may aggravate any co-existing gynecomastia.

In the most severe cases, male patients have ended up with large, D-cup sized breasts.

Treatment in most cases requires only removing the cause – which for Invega patients may require discontinuing Invega and switching to a different medication.

Some of the more severe cases of gynecomastia may still linger even after the cause is removed.

These patients may need to resort to surgical treatments like breast reduction surgery, mastectomy, or liposuction.

Such procedures come with the usual potential for complications associated with most surgery, such as pain, recovery time, and the risk of infection.

Clinically, the deformity associated with gynecomastia isn’t considered a serious risk to the patient’s physical health.

It’s the emotional effects that tend to be truly disruptive, especially for young boys. Developing visible breasts during youth or adolescence can subject young male patients to severe and traumatizing social stigma.

Studies show that boys with gynecomastia scored lower on all studied measures of psychological well-being. Gynecomastia patients received lower scores for social functioning, mental health, self-esteem and eating behaviors, as well as for general health.