Trial Date Set as Thousands Sue Pfizer Over Birth Control Linked to Brain Tumors
This should be a much bigger story.
This article originally appeared on The Defender and was republished with permission.
Guest post by Michael Nevradakis, Ph.D.
More than 2,000 women who developed brain tumors joined a class action lawsuit, which was filed in 2024. The women claim Pfizer knew that long-term use of its popular birth control injection, Depo-Provera, could cause debilitating and potentially incurable brain tumors, but that the drugmaker didn’t warn patients or regulators.
A class action lawsuit claiming that Depo-Provera, Pfizer’s popular birth control injection, caused brain tumors, is headed to trial.
A total of 2,132 women who developed brain tumors joined the class action lawsuit, which was filed in 2024. The women claim Pfizer knew that long-term use of Depo-Provera is linked to benign, though debilitating and potentially incurable brain tumors, but the drugmaker didn’t warn patients or regulators.
“Defendants willfully, wantonly, and intentionally conspired, and acted in concert, to ignore relevant safety concerns and to deliberately not study the long-term safety and efficacy of Depo-Provera, particularly in chronic long-term users of Depo-Provera,” the complaint states, according to an excerpt quoted by NBC News.
According to the Daily Mail, Depo-Provera “contains progestin, a synthetic version of the hormone progesterone, which prevents pregnancy by stopping ovulation and thinning the lining of the uterus.” The injection is administered every three months.
The U.S. Food and Drug Administration (FDA) licensed the drug in 1992.
Virginia Buchanan, partner at law firm Levin Papantonio, which filed the lawsuit, told the Daily Mail, “The basis of this lawsuit is there should have been a warning” about the risk of meningiomas — the most common type of benign brain tumor.
NBC News reported that Pfizer filed a motion to dismiss the lawsuit in September 2025, arguing that when the company became aware of the product’s link to meningioma in 2023, it asked the FDA to add a warning to the drug’s label. The FDA initially rejected the application.
Judge M. Casey Roberts of the U.S. District Court for the Northern District of Florida rejected Pfizer’s motion and, last week, set a Dec. 7 trial date in the case.
In December 2025, Pfizer added a warning label to Depo-Provera about the risk of meningiomas, after the FDA approved the change.
According to Medscape, the updated label states that “cases of meningiomas have been reported following repeated administration” of Depo-Provera, “primarily with long term use.”
Buchanan said the label update was “long-overdue” and “underscores the validity of these women’s claims against Pfizer.”
“Pfizer would have known exactly how to investigate safety signals and update warning labels, but they did not. Instead, women and their doctors were not given the information they needed to make informed choices about their health, and many have gone on to suffer from life threatening injuries as a result,” Buchanan said.
Data from the Centers for Disease Control and Prevention (CDC) indicates that 1 in 4 sexually active women in the U.S. have used Depo-Provera. The Daily Mail reported that 2 million women take the drug each year.
The lawsuits against Pfizer were filed in both federal and state courts. The federal cases were consolidated into multidistrict litigation.
According to The Guardian, the total claims may exceed “several billion dollars,” while the total number of lawsuits is expected to rise to “between 5,000 and 10,000 from women in the US.”
The Daily Mail reported that the December trial will hear the claims of one of the plaintiffs, while “trials for four other plaintiffs will occur every 60 days after,” unless Pfizer decides to settle or resolve the claims before trial.
FDA regulator who rejected Depo-Provera label change now works for Pfizer
According to STAT, meningiomas grow slowly and usually are not cancerous. But they can cause other symptoms, including vision or hearing loss and seizures. Meningiomas often require surgical removal, but the procedure can damage brain structures near the site of the tumor.
Meningiomas grow along the meninges, a membrane surrounding the brain and spinal cord. The tumors can result in death due to their location.
Bone mineral density loss, blood clots and breast cancer are among the other serious adverse events linked to meningioma.
According to the National Brain Tumor Society, more than 39,000 people in the U.S. are diagnosed with meningioma each year.
The FDA Adverse Event Reporting System (FAERS) lists a total of 43,896 adverse event reports filed in connection with Depo-Provera between 1969 and 2024. Of these, 34,094 involve serious cases, including deaths.
According to STAT, the FDA initially rejected Pfizer’s 2023 request to update its product label to reflect the risk of meningioma.
As a result, Pfizer believed it wasn’t liable for any of the meningioma claims because the claims, many of which were filed in state courts, would be preempted by federal law — in this case, the FDA’s rejection of its updated product label.
This legal principle, known as the preemption doctrine, “has often been used by pharmaceutical companies to deflect state-law claims that they should have known about a harmful side effect but were prevented from updating product labeling because the FDA did not approve its proposed changes,” STAT reported.
But according to STAT, Pfizer’s argument may be undermined by the actions of the European Medicines Agency, which in 2024 recommended a labelling change for Depo-Provera to reflect the product’s link to meningioma.
According to NBC News, Canadian regulators also updated Depo-Provera’s label that year, adding meningioma to the product’s “warnings and precautions” section.
Pfizer submitted a newly revised label update to the FDA in June 2025. The FDA approved it in December of that year.
“The FDA acted only after reviewing additional evidence, including major studies,” said immunologist and biochemist Jessica Rose, Ph.D. “This delay by the FDA left U.S. patients uninformed.”
“Pfizer first identified a potential link in 2023 and sought label changes promptly, denying any earlier knowledge. Both Pfizer and the FDA are culpable,” Rose said.
Karl Jablonowski, Ph.D., senior research scientist for Children’s Health Defense, said the FDA’s initial rejection of Pfizer’s updated product label for Depo-Provera may reveal a conflict of interest.
He said the rejection letter “likely originated” from the FDA’s Center for Drug Evaluation and Research. At the time, Dr. Patrizia Cavazzoni, a former Pfizer employee, was director of the center. She has since rejoined Pfizer as chief medical officer and executive vice president.
“If Pfizer truly thought a product warning label was the best course of action, why is the person responsible for denying that label change now sitting in a Pfizer executive office?” Jablonowski asked. “The conflicts are thick and blatant.”
Buchanan told the Daily Mail that Pfizer continues to deny wrongdoing and that the case “brings about the opportunity to have a trial, have the experts, have the documents, all of the things that a well-informed jury would need to know to corroborate what we’ve been contending all along.”
Several studies linked Depo-Provera to risk of brain tumors
Several recent studies found significant health risks linked to Depo-Provera. The lawsuit claims there are studies citing the link that date back to 1983.
A 2024 study published in The BMJ of 18,000 women who underwent meningioma surgery found that use of Depo-Provera for a year or more was linked to a 5.6-fold increased risk of developing a meningioma.
A 2025 Cleveland Clinic study in JAMA Neurology linked medroxyprogesterone acetate, the drug in Depo-Provera, with a “statistically significant increased relative risk of developing a meningioma diagnosis.”
Another 2025 study in Expert Opinion on Drug Safety found that the use of Depo-Provera for over a year by women of childbearing age was connected to a 3.5-fold higher risk of developing a meningioma.
Dr. Angus Dalgleish, professor of oncology at City St. George’s, University of London, said it is “inconceivable that Pfizer was not aware of the risk,” adding that “the FDA seems to have been slow and perhaps reluctant to act.”
Dalgleish drew a parallel with a failed attempt by Pfizer and the FDA to hide the results of their clinical trials for the Pfizer-BioNTech COVID-19 vaccine for 75 years.
“The FDA’s complicity in ignoring clear and present danger signs suggests a pattern of behavior that has been established over many years,” Dalgleish said.
“Pfizer has a long criminal rap sheet,” said internal medicine physician Dr. Clayton J. Baker. “Since 2000, Pfizer and its subsidiaries have been found guilty of 107 offenses totaling a staggering $11,261,560,400. At least 22 of those were violations of the False Claims Act — meaning Pfizer has been found guilty of defrauding the government an astonishing 22 times in the last 25 years.”
A response by the American College of Obstetricians and Gynecologists (ACOG) to the 2024 BMJ study stated that women face an “incredibly small” risk of developing a meningioma following use of Depo-Provera.
Jablonowski questioned ACOG’s conclusion. “ACOG cannot possibly know that the risk is ‘incredibly small,’” he said. He added:
“Meningiomas often present with subtle and/or non-specific symptoms and are slow-growing. Many people may attribute the symptoms to aging, and the condition may remain undiagnosed. ACOG is minimizing the risk without even acknowledging the scope of that risk.”
Buchanan told the Daily Mail that she observed “some real and life-changing issues occurring” among the plaintiffs, many of whom “are not who they used to be.” She said women can still join the class action against Pfizer.
U.S. law firm Berger Montague is investigating whether Pfizer’s board of directors breached its fiduciary duty by marketing Depo-Provera as safe. This could result in legal action by shareholders against Pfizer.
Law firms in Europe, Canada, Australia and South Africa “are also investigating potential class actions,” the Daily Mail reported.
Related articles in The Defender
Pfizer Hiding Popular Contraceptive’s Link to Brain Tumors, Lawsuit Alleges
FDA, Pfizer Silent on Brain Tumor Risk Linked to Injectable Contraceptive
Pfizer Has a Long History of Fraud, Corruption and Using Children as Human Guinea Pigs
How the Government Is Trying to Silence a COVID Vaccine Whistleblower
Judge Gives FDA 8 Months, Not 75 Years, to Produce Pfizer Safety Data
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