Two antipsychotic medications, Risperdal and Invega, are used to treat a variety of disorders including schizophrenia and bipolar disorder. Risperdal, in particular, is also used to treat symptoms of irritability in children with autism spectrum disorders. Both drugs are used off-label to treat many other conditions like ADHD, obsessive-compulsive disorder, depression, dementia, post traumatic stress disorder and more.

Scientists believe these antipsychotic medications can raise a man‘s prolactin levels and cause him to develop enlarged male breast tissue, or gynecomastia, as a result.

Risperdal and Invega, in addition to treating psychiatric symptoms, can also disrupt the hormones in a patient‘s body. In particular, it can cause increased production of a hormone named prolactin, which causes some men to grow breasts or begin lactating.

Prolactin is a hormone that is responsible for stimulating breast development and milk production in women. Males also have circulating prolactin hormone levels in their bodies, but their levels are much lower than a woman‘s.

In addition to enlarged male breast tissue and male milk production, men who take Risperdal or Invega may also develop breasts that are painful and they may experience nipple pain or discharge.

Consequently, many males who go on to develop male breast tissue, pain, nipple discharge and other issues after having taken Invega or Risperdal go on to have psychological difficulties as a result of their changing body.

Thousands of lawsuits have been filed against the makers of Risperdal and Invega by males who have gone on to develop large male breast tissue. Some of these men have breasts that have been large to a size D cup or larger.

Plaintiffs in these lawsuits accuse the drug makers of being well aware that these drugs cause male breast tissue to develop into gynecomastia, yet failing to adequately inform patients in the public of the severe side effects. Lawsuits allege that these companies knew about these side effects since at least 2003 and likely earlier but did not pass this information on to doctors and patients.

Several verdicts have been reached in some of these lawsuits, with several of them ordering a payout to the plaintiffs for millions of dollars.

Not only have private plaintiffs filed against Johnson & Johnson, makers of Risperdal, but the U.S. Department of Justice was also involved in litigation against the company at one point as well.

In November 2013, Johnson and Johnson agreed to pay $2.2 billion in a settlement resolving many allegations about its marketing practices. Among other things, the company was accused of inappropriately marketing Risperdal to older adults, children, and those with developmental disabilities.