In this first-published Study study, researchers compared over 8,000 men who suffered from gynecomastia with nearly 83,000 controls. The men were 40 to 85 years of age, and the data was from a period between June 2001 and June 2011.
The results showed that men taking Risperdal had a 69 percent increased risk of gynecomastia compared to men who did not take the medication. Risperdal was also shown to create a 40 percent higher risk of the disorder than other anti-psychotics like Seroquel or Zyprexa.
More information from an earlier report in Medscape: