Mass torts rarely announce themselves. They begin with a single complaint that connects three things the medical literature has long treated separately: a drug's known mechanism, a disease that mechanism plausibly promotes, and a label that never mentioned the connection. When the plaintiffs' bar recognizes that pattern in a drug taken by millions, the litigation that follows can run for a decade.

Brown v. Johnson & Johnson et al., filed in Alameda County Superior Court in April 2025 by the Wisner Baum firm, fits that template precisely. The plaintiff, a California woman named Bridgett Brown, alleges that brand-name and generic versions of Risperdal (risperidone) and Zyprexa (olanzapine) caused her breast cancer, and that Johnson & Johnson, its Janssen subsidiary, Eli Lilly, and a European licensee concealed the risk for decades. The defendants removed the case to federal court; it was remanded to Alameda County in 2025, and according to plaintiffs' counsel, related cases are moving forward there in 2026. The defendants deny the allegations. The litigation is at an early stage. But the mechanism it describes is not speculative, and the marketing history it invokes is a matter of public record.

The Mechanism: Dopamine, Prolactin, and the Breast

Most antipsychotics work by blocking dopamine D2 receptors in the brain. Dopamine also acts as the body's brake on prolactin, the pituitary hormone that drives milk production after childbirth. Block dopamine, and prolactin rises. This effect, hyperprolactinemia, has been documented in the prescribing literature for these drugs since their approval. It is the reason Risperdal has been linked to gynecomastia, the growth of breast tissue in boys and men, which produced its own wave of litigation.

The question in Brown is whether the same hormone that grows breast tissue in males also promotes malignancy in females. The plaintiff points to epidemiology that has accumulated over the past decade. The most frequently cited is a 2021 study led by Dr. Tahir Rahman at Washington University School of Medicine in St. Louis, published in the Journal of Clinical Psychopharmacology, which analyzed records of more than 540,000 women taking antipsychotics. Women on high-prolactin agents (a category that includes risperidone, paliperidone, and haloperidol) had a 62 percent higher relative risk of breast cancer than women on anticonvulsants or lithium; women on mid-prolactin agents (a category that includes olanzapine) had a 54 percent higher risk. Drugs that do not raise prolactin, such as aripiprazole, showed no elevated risk.

Dr. Rahman was measured about the implications, noting that antipsychotics are lifesaving for many patients and that the finding argues for monitoring prolactin rather than abandoning treatment. He also observed that prolactin testing is inexpensive and elevated levels are relatively easy to mitigate. That observation, in a lawsuit, becomes an allegation: a cheap, feasible precaution existed and the label did not prompt it.

What the Complaint Alleges

According to the firm's public description of the case, the complaint asserts strict liability, negligence, and fraud, and seeks compensatory and punitive damages. Its central factual claims are that:

• The manufacturers possessed internal data for more than two decades showing their products significantly elevated prolactin.
• Risperdal's label, until 2025, stated that neither clinical trials nor epidemiological studies had shown an association between chronic administration of this class of drugs and tumorigenesis in humans.
• The companies designed trials with small samples and short follow-up periods that could not detect a cancer signal, delayed unfavorable publications, and funded research that minimized the mechanism.
• Neither Ms. Brown nor her prescribing physicians were warned, and had they been, she would have chosen a safer alternative.

Every one of these allegations is contested and unproven. But readers who followed the earlier Risperdal litigation will recognize the shape of the argument, because a jury has accepted a version of it before.

The Prior Record

This is not the first time these drugs have been in court over how they were sold. In January 2009, Eli Lilly pleaded guilty to a misdemeanor and agreed to pay $1.415 billion to resolve criminal and civil allegations that it promoted Zyprexa for unapproved uses, including dementia in the elderly. The $515 million criminal fine was, at the time, the largest ever imposed on a corporation in a U.S. criminal prosecution.

In November 2013, Johnson & Johnson agreed to pay more than $2.2 billion, and Janssen pleaded guilty to misbranding Risperdal, to resolve allegations of off-label promotion to children, the elderly, and the developmentally disabled, along with kickbacks to a long-term care pharmacy. The government alleged that Janssen downplayed the drug's risks in its marketing, including the risk of gynecomastia.

Then came the gynecomastia trials. In 2019, a Philadelphia jury awarded $8 billion in punitive damages to a man who developed breasts after taking Risperdal as a child; the award was later drastically reduced, but the liability finding stood on a failure-to-warn theory tied to prolactin. The plaintiffs' bar took note. The current breast cancer litigation is, in a sense, the second act of a play whose first act ended with a verdict.

None of that history proves causation in Ms. Brown's case. It does bear on notice, on what the companies knew about prolactin and when, and on the credibility of a defense that the risk was unknowable. Off-label prescribing is legal and often appropriate. Off-label promotion by a manufacturer is not, and both companies have admitted to it.

Why This Could Scale

Three features of this litigation make it a candidate for consolidation rather than a one-off.

The exposed population is enormous. Risperdal and Zyprexa were blockbusters, and their generics remain among the most prescribed psychiatric medications in the country. Because both were promoted beyond schizophrenia into bipolar disorder, autism-related irritability, agitation in dementia, and adjunctive treatment for depression, the number of women with long-term exposure runs into the millions.

The mechanism is shared across products. The Rahman study grouped drugs by their effect on prolactin, not by brand. That means the same expert testimony and the same biological literature apply to risperidone, paliperidone (Invega), and olanzapine alike, and the plaintiffs' firm has already named Invega in its litigation description.

And the label history is documentary. A failure-to-warn case lives or dies on what the label said and when it changed. If, as alleged, the Risperdal label affirmatively denied any tumorigenesis association until 2025, the timeline of what the companies knew before that date will be the center of discovery.

The Defense Case

The defendants will have serious arguments. Observational studies show association, not causation, and women with serious mental illness differ from the general population in ways (parity, smoking, obesity, screening rates) that complicate any breast cancer comparison. Prolactin's role in human breast cancer, as distinct from rodent models, remains debated in the endocrinology literature, a point Dr. Rahman's own colleagues have made. And the drugs carry undisputed benefits for patients with psychosis; a warning that frightens patients off effective treatment carries its own risk.

The plaintiffs' response will be that the standard is not certainty but reasonable warning, that a label's job is to let physicians weigh risks they are told about, and that a company cannot claim the science was unsettled while designing studies incapable of settling it.

What to Watch

As of early October 2026, the litigation remains concentrated in Alameda County Superior Court, and no multidistrict litigation has been established for these claims. Because the cases were sent back to state court, any consolidation, if filings grow, may run through California's state coordination procedure rather than a federal MDL. Expect, too, that the 2025 label change, whatever prompted it, will become a focal point: defendants will cite it as evidence of responsible updating; plaintiffs will ask why it took until 2025.

For women who took these medications for years and later received a breast cancer diagnosis, the practical guidance is unglamorous: preserve pharmacy records, request prescribing histories, and consult counsel familiar with pharmaceutical failure-to-warn litigation. For the industry, the lesson is older than any of these drugs. A mechanism you disclose is a risk you managed. A mechanism you minimize is a case waiting to be filed.

Key Takeaways

• Brown v. Johnson & Johnson (Alameda County, Cal., No. 25CV119808), filed April 2025, alleges that Risperdal and Zyprexa caused breast cancer by elevating prolactin and that J&J, Janssen, and Eli Lilly concealed the risk. After removal to federal court, the case was remanded to Alameda County in 2025.
• A 2021 Washington University study of more than 540,000 women found a 62% higher relative breast cancer risk with high-prolactin antipsychotics (including risperidone) and 54% with mid-prolactin agents (including olanzapine).
• Both manufacturers previously pleaded guilty to misbranding: Lilly ($1.415 billion, 2009) and J&J/Janssen ($2.2 billion, 2013), for off-label promotion of these drugs.
• The exposed population, shared mechanism across risperidone, paliperidone, and olanzapine, and a documentary label history make this litigation a candidate for consolidation; as of October 2026, no MDL exists.
• All allegations are contested; the litigation is at an early stage and no court has found causation.

Frequently Asked Questions

Is there a lawsuit claiming Risperdal or Zyprexa causes breast cancer?

Yes. Brown v. Johnson & Johnson et al. was filed in Alameda County Superior Court, California, in April 2025 by Wisner Baum. It alleges that Risperdal (risperidone) and Zyprexa (olanzapine) caused the plaintiff's breast cancer through elevated prolactin and that the manufacturers failed to warn. After a removal and remand, related cases are proceeding in Alameda County. The defendants deny the claims.

How could an antipsychotic cause breast cancer?

Antipsychotics block dopamine D2 receptors. Dopamine normally suppresses prolactin, so blocking it raises prolactin levels (hyperprolactinemia). Prolactin stimulates breast tissue, and elevated prolactin has been associated with increased breast cancer risk in epidemiological studies. Causation in humans remains debated.

What does the research show about antipsychotics and breast cancer?

A 2021 study in the Journal of Clinical Psychopharmacology analyzing more than 540,000 women found a 62% higher relative risk of breast cancer among women taking high-prolactin antipsychotics and 54% higher among those taking mid-prolactin agents, compared with women on anticonvulsants or lithium. Drugs that do not raise prolactin showed no increased risk.

Which drugs are involved in the antipsychotic breast cancer litigation?

Risperdal (risperidone) and Zyprexa (olanzapine) are named in the Brown complaint. Invega (paliperidone), a related J&J product, has been identified by plaintiffs' counsel as part of the same litigation theory.

Have J&J and Eli Lilly been penalized before over these drugs?

Yes. Eli Lilly paid $1.415 billion in 2009 and J&J paid more than $2.2 billion in 2013 to resolve federal allegations of off-label promotion; subsidiaries of both pleaded guilty to misbranding. In 2019 a Philadelphia jury returned an $8 billion punitive verdict (later reduced) in a Risperdal gynecomastia case.

Is this a class action or an MDL?

Neither, as of October 2026. The claims are individual lawsuits proceeding in Alameda County Superior Court. If many similar cases are filed, they may be coordinated, either in California state court or, for federal filings, in a multidistrict litigation.

About the Author

Fadi Agour, J.D., is a licensed attorney and the founder and CEO of FadiLaw Marketing LLC, the Houston-based parent company of Best Case Leads, Real Performance Marketing, Masstortsco, and Redostar. For more than seven years he has built performance-marketing companies that connect injured consumers with the plaintiff law firms equipped to represent them. His companies have earned a place on the Inc. 5000 list of America's fastest-growing private companies seven consecutive times (7x Badge). He writes about mass tort litigation, product liability, and the business of plaintiff law.

Sources and Further Reading

1. Wisner Baum, "Wisner Baum Files Lawsuit Alleging J&J and Eli Lilly Concealed Antipsychotic Breast Cancer Risks" (Apr. 2025): https://www.wisnerbaum.com/blog/2025/april/wisner-baum-files-lawsuit-alleging-j-j-and-eli-l/
2. HarrisMartin, "Lawsuit Says Antipsychotic Drugs Risperdal, Zyprexa Cause Breast Cancer" (Alameda County Superior Court complaint, Apr. 21, 2025): https://www.harrismartin.com/publications/4/drugs/articles/60558/lawsuit-says-antipsychotic-drugs-risperdal-zyprexa-cause-breast-cancer/
3. Wisner Baum, Zyprexa litigation page (2026 status in Alameda County): https://www.wisnerbaum.com/prescription-drugs/zyprexa-lawsuit/
4. Reich & Binstock, Risperdal breast cancer lawsuit overview (remand; no MDL): https://www.reichandbinstock.com/houston-personal-injury-lawyers/defective-medical-devices-and-pharmaceutical-injuries/risperdal/
5. Washington University School of Medicine, "Antipsychotic drugs may increase risk of breast cancer" (Dec. 2021), summarizing Rahman et al., Journal of Clinical Psychopharmacology: https://medicine.wustl.edu/news/antipsychotic-drugs-may-increase-risk-of-breast-cancer/
6. MDedge / The Hospitalist, "More evidence ties some antipsychotics to increased breast cancer risk" (hazard ratios 1.62 and 1.54): https://mdedge.com/breast-cancer-icymi/article/249956/breast-cancer/more-evidence-ties-some-antipsychotics-increased
7. S. Department of Justice, "Eli Lilly and Company Agrees to Pay $1.415 Billion to Resolve Allegations of Off-label Promotion of Zyprexa" (Jan. 15, 2009): https://www.justice.gov/opa/pr/eli-lilly-and-company-agrees-pay-1415-billion-resolve-allegations-label-promotion-zyprexa
8. NPR, "Johnson & Johnson To Pay $2.2 Billion In Marketing Settlement" (Nov. 4, 2013): https://www.npr.org/sections/health-shots/2013/11/04/242989557/risperdal-johnson-johnson-to-pay-2-2-billion-in-marketing-settlement
9. Healthcare Finance News, "Johnson & Johnson pays $2.2B in criminal and civil settlements" (Nov. 2013): https://www.healthcarefinancenews.com/news/johnson-johnson-pays-22b-criminal-and-civil-settlements
10. Wisner Baum, Risperdal litigation page (label language, case number 25CV119808): https://www.wisnerbaum.com/prescription-drugs/risperdal-lawsuit/
11. Wisner Baum, Antipsychotics and Breast Cancer litigation overview (Invega): https://www.wisnerbaum.com/prescription-drugs/antipsychotics-and-breast-cancer-lawsuits/
12. KevinMD, Martha Rosenberg, "Drug giants face suit over hidden cancer risks" (Sept. 20, 2025): https://kevinmd.com/2025/09/drug-giants-face-suit-over-hidden-cancer-risks.html

 

This article is provided for general informational and educational purposes only. It is not legal advice, does not create an attorney-client relationship, and should not be relied upon as a substitute for consultation with a licensed attorney about your specific circumstances. Allegations in pending litigation described here have not been adjudicated, and defendants deny them. Case status, settlement terms, and deadlines change; verify current information with counsel.