Multiple studies have found that Risperdal (risperidone) and Zyprexa (olanzapine) significantly increase the risk of breast cancer. According to the complaint, Johnson & Johnson and Eli Lilly knew of the breast cancer risks for decades but failed to warn consumers, all while profiting billions in drug sales. This is the first lawsuit to allege that these antipsychotic drugs cause breast cancer.
A lawsuit filed in Alameda County Superior Court alleges pharmaceutical giants Johnson & Johnson and Eli Lilly knowingly concealed evidence that their blockbuster antipsychotic medications cause breast cancer. Attorneys say the companies aggressively marketed Risperdal and Zyprexa to vulnerable populations while concealing evidence dating back to the 1990s linking the drugs to significantly increased cancer risks.
Wisner Baum filed the complaint on behalf of plaintiff Bridgett Brown, a California resident, who was prescribed both brand-name and generic versions of Risperdal and Zyprexa. Ms. Brown was never warned that these drugs could cause breast cancer, as the manufacturers failed to provide adequate warnings about this risk, the complaint alleges. Had she or her prescribing physicians been properly informed, Ms. Brown would not have taken these medications or would have sought safer alternatives.
According to the lawsuit, Ms. Brown was diagnosed with breast cancer in approximately 2024 and continues to suffer physical injury, emotional distress, and related consequences.
Allegations in Antipsychotic Lawsuit
The complaint centers on the drugs’ known capacity to cause hyperprolactinemia—a hormonal imbalance directly tied to breast cancer development—and cites the following studies published over the last few years:
- 62% increased breast cancer risk for high-prolactin drugs like Risperdal and 54% increased risk for medium-prolactin drugs like Zyprexa – A study of 540,737 women (Rahman, 2023)
- 59% increased breast cancer risk for Risperdal – A review of 15 studies conducted on over 1 million individuals (Bird, 2025)
- 47% increased breast cancer risk after 5+ years of exposure to prolactin-increasing antipsychotics like Risperdal and Zyprexa – A Swedish registry study of 132,061 women (Solmi, 2024)
Otherwise known as atypical antipsychotics, these drugs were at first narrowly approved for the treatment of severe schizophrenia. But with less than 1% of the general population diagnosed with schizophrenia, the drugs were not initially “blockbusters” for their manufacturers, according to the lawsuit.
The companies subsequently broadened their customer base, the lawsuit continues, by gaining approval for mild indications in new patient populations and by promoting the drugs for off-label use, including the treatment of ADD in children and dementia in the elderly. As a result of this off-label use, atypical antipsychotics became blockbuster drugs, generating billions in profit for the defendants.
“These companies transformed narrow-use schizophrenia drugs into multi-billion-dollar per year blockbusters by targeting extremely vulnerable segments of our population, all while hiding a cancer risk they’ve known about for decades,” said Pedram Esfandiary, attorney for the plaintiff.
Elevated Prolactin and Breast Cancer Link Known for Decades
The connection between elevated prolactin and breast cancer has been scientifically established since the 1970s, with studies dating back to the 1990s confirming that atypical antipsychotics cause hyperprolactinemia. Despite this knowledge, the lawsuit alleges that drug labels actively denied any cancer risk stating, until 2025, that "neither clinical trials nor epidemiological studies conducted to date have shown an association between chronic administration of this class of drugs and tumorigenesis in humans."
Attorneys say that even with the recent label update in January of 2025, the defendants still dismiss their drugs’ breast cancer risk, misleadingly and incorrectly stating that published studies are “inconsistent.”
“The science has been clear on prolactin-elevating antipsychotics for decades,” said Monique Alarcon, attorney for the plaintiff. “These companies had a duty to inform; they failed, and now individuals nationwide are suffering the consequences. We intend to hold them accountable.”
Multiple alternative antipsychotics are available that do not pose the same risk, such as Abilify (aripiprazole), Clozaril (clozapine), Geodon (ziprasidone), and Seroquel (quetiapine).
The complaint seeks compensatory and punitive damages, alleging strict liability for failure to warn, negligence, and fraud. The case is Brown v. Johnson & Johnson et al (Case No. 25CV119808).
If you developed breast cancer after taking Risperdal, Invega, or Zyprexa, you may qualify for a lawsuit. Contact the legal team at Wisner Baum today for a free and confidential case evaluation. We represent clients on a contingency fee basis, which means you don’t pay unless we obtain compensation for you.
