Depo-Provera Shots Triple Meningioma Brain Tumor Risks After Just One Year: Study

For every 1,111 women who receive the Depo-Provera birth control shot for a year or more, researchers estimate one will develop a brain tumor.

The findings of a new study appear to confirm the risk women face of developing meningioma from Depo-Provera shots, indicating that receiving the quarterly injections for more than one year may result in a 3.55 times greater brain tumor risk, compared to those using certain oral contraceptives.

Depo-Provera is a hormonal birth control shot that was approved by the U.S. Food and Drug Administration (FDA) in 1992, which has been used by more than 70 million women, based on the belief that it is a safe and effective means of preventing pregnancy.

However, concerns over Depo-Provera brain tumor side effects began to emerge last year, after a different study was published in The BMJ, which concluded that Depo-Provera users were more likely to develop intracranial meningioma tumors, often resulting in the need for ongoing monitoring and in severe cases, surgical intervention.

As a result of those earlier findings, a growing number of women throughout the U.S. have been pursuing Depo-Provera lawsuits against the manufacturers, each raising similar allegations that false and misleading information has been provided about the potential side effects of the birth control shot. However, as more women learn that they may have developed a meningioma from Depo-Provera, the size and scope of the litigation is expected to continue to expand.

Annual Depo-Provera Injections Linked to 3x Meningioma Risk

Since the release of The BMJ study, there have been few efforts to quantify the actual risk of brain tumors among women who received regular Depo-Provera injections. However, this gap in research was recently addressed by a team from the University of British Columbia.

While the results have not yet been published or subjected to peer review, the new Depo-Provera study (PDF) suggests that for every 1,111 women receiving Depo-Provera shots for one year, at least one may experience a meningioma.

The research was led by Dr. Mahyar Etminan, comparing brain tumor rates between Depo shot recipients and users of traditional birth control pills. The study involved more than 72,000 Depo-Provera recipients and 247,000 birth control pill users.

According to the findings, women who received the Depo-Provera shot for at least a year faced 3.55 times the risk of developing a meningioma than their oral contraceptive counterparts.

The study points to actions taken by Pfizer in other countries, in which the drug maker updated the Depo-Provera special warnings and precautions for use label in the European Union (EU) and the United Kingdom to now list meningioma as a possible side effect. However, the manufacturer has failed to add Depo-Provera meningioma warnings to the label in the U.S.

“Recently, the European Medicines Agency has recommended the addition of meningioma as a warning in the drug’s label. However, to date, a label change has not taken place by the Food and Drug Administration,” Etminan’s team concluded. “Our study adds to the existing body of evidence that MPA can increase the risk of meningioma. We believe the results of this study further warrants the need to alert women about this serious, albeit rare adverse event.”

February 2025 Depo-Provera Brain Tumor Lawsuit Update

This new research gomes as the number of Depo-Provera lawsuits being brought in federal courts nationwide continues to grow. Given similar allegations of fact and law raised in complaints filed in various different federal district courts, a group of plaintiffs filed a motion with the U.S. Judicial Panel on Multidistrict Litigation (JPML) in November 2024, asking that all claims be centralized before one judge in the Northern District of California, for coordinated discovery and pretrial proceedings as part of a Depo-Provera MDL (multidistrict litigation).

Given the growing evidence linking Depo-Provera shots to meningioma brain tumors, some estimates suggest that thousands of lawsuits may ultimately be filed in the coming months and years. Plaintiffs argue that the establishment of an MDL for the Depo-Provera lawsuits will help prevent duplicative discovery into common issues, avoid contradicting rulings, and serve the convenience of all parties, witnesses and the court system.

Following the motion, both Pfizer and manufacturers of generic versions of the birth control shot, confirmed that they also supported consolidation. However, they indicated it would be more appropriate to centralize the litigation in the Southern District of New York, close to Pfizer’s headquarters.

The parties presented their arguments to the JPML last week, and a decision is pending. If the JPML agrees to consolidate the lawsuits into a Depo-Provera MDL, all current and future claims will be transferred to one judge for coordinated discovery, pretrial motions and potentially a series of early bellwether test cases.

However, if the parties fail to reach Depo-Provera brain tumor settlements or another resolution for the litigation after all pretrial proceedings are concluded, each individual lawsuit may later be remanded back to the U.S. District Court where it was initially filed for an individual trial in the future.