Men and boys who use Invega to treat psychiatric conditions may be at risk for developing Invega male breasts.

Invega is a psychiatric drug approved by the FDA as a treatment for schizophrenia. Doctors can prescribe Invega as a treatment for other conditions besides schizophrenia on a case-by-case basis.

Also known by the generic name paliperidone, Invega has been available for sale in the U.S. since 2006.

Invega is one of a group of drugs known as atypical antipsychotics. Sometimes known as second-generation antipsychotics, these drugs were developed to have fewer side effects than the older generation of antipsychotic drugs. But later research and post-market reports show these drugs present side effects of their own.

Scientist believe Invega works by moderating the activity of the neurotransmitters dopamine and serotonin. Tempering the effects of these neurotransmitters seems to help keep schizophrenia symptoms under control.

What Causes Invega Male Breasts?

Unfortunately, Invega’s effect on dopamine may also lead to the development of Invega male breasts.

By reducing the activity of dopamine, Invega may stimulate the pituitary gland to produce more of the hormone prolactin. Prolactin triggers growth of breast tissue and production of breast milk.

While prolactin can be present in both males and females, levels of the hormone tend to be naturally higher in women who are pregnant or are breastfeeding. But prolactin can have the same effects in males whose prolactin levels have been artificially increased.

Such an increase, known as hyperprolactinemia, can be a side effect of Invega and other atypical antipsychotics. Studies of antipsychotic drugs similar to Invega show elevated prolactin levels in as much as 90 percent of persons who take those drugs.

That increase puts male patients of any age at risk for developing Invega male breasts, a condition known clinically as gynecomastia.

Effects of Gynecomastia

Gynecomastia can be seriously deforming. Male patients with this condition can grow breasts as large as any woman’s. Breast growth may be uneven: one may grow larger than the other, or only a single breast may grow at all.

In most cases, gynecomastia gradually resolves on its own after whatever is causing it is removed.

Some cases are more stubborn than that, however. Patients in that situation may have to resort to breast reduction surgery, with all the potential risks that surgery comes with.

Clinically, gynecomastia isn’t considered a very physically damaging condition. It’s the psychological residuals that tend to cause the most trouble.

These effects can be most problematic in young boys and teenagers, who are most vulnerable to abuse by their peers.

A 2013 study conducted at Boston Children’s Hospital found that boys with gynecomastia scored lower on several measures of psychological health, including social functioning, eating behaviors, and self-esteem.

Hundreds of patients who experienced gynecomastia say their side effects grossly exceeded those they were led to expect by the information and warnings that accompanied their medication.

These patients have turned to the courts for redress, alleging drug makers like Janssen Pharmaceuticals failed to properly warn about the risk of gynecomastia side effects associated with atypical antipsychotic drugs.