Depo-Provera Birth Control Injection Linked to 53 Percent Greater Brain Tumor Risk

A substantial body of research has linked a popular birth control injection—medroxyprogesterone acetate (MPA), marketed under the brand name Depo-Provera®—to meningiomas, the most common type of brain tumor. While meningiomas are typically classified as benign, untreated tumors or atypical and malignant cases can still grow aggressively and lead to life-threatening complications such as increased intracranial pressure or brain herniation (when brain tissue shifts from its normal position, compressing surrounding structures).^{1 2}

The growing number of studies has prompted both class-action and individual lawsuits against Pfizer, the drug’s manufacturer, with some countries outside the United States starting to require clear warnings about the widely prescribed contraceptive. Canada’s labeling clearly states that meningiomas have been reported, and the European Union (E.U.) updated its guidance last fall, advising that patients “should be monitored” for signs of meningioma. In contrast, the U.S. label for Depo-Provera contains no mention of brain tumors and offers no guidance on monitoring.³

The research linking Depo-Provera to this outcome is substantial and increasingly consistent. One study found that women who received the shot, compared with those who used oral contraceptives, had a “significantly higher risk” of developing meningioma. Another study reported that women who took MPA injections for at least one year faced a fivefold increase in risk. The study authors noted, “A significant excess risk was found with prolonged use (≥1 year) of injectable medroxyprogesterone acetate, a progestogen widely used as a contraceptive.” Importantly, the study authors clarified that “only prolonged use of injectable medroxyprogesterone acetate was consistently associated with an increased risk of meningioma,” strengthening the case for a causal relationship with the birth control shot.^{4 5}

Studies have generally found that oral contraceptives containing similar progestins do not carry the same level of risk as the injectable formulation. A 2024 study further reinforced this pattern, showing that while oral MPA exposure was not linked to meningioma, injectable exposure was associated with a 53% increase in odds of developing the tumor. These findings highlight a growing consensus in the scientific community that the injectable form of MPA carries unique and serious risks.⁶

Pfizer Rejects Plaintiffs’ Allegations Amid History of Multi-Million Depo-Provera Settlements

Hundreds of Depo-Provera lawsuits allege that Pfizer “knew or should’ve known” about the brain tumor risks associated with their birth control shot and failed to warn consumers. The first Depo-Provera meningioma lawsuit was filed in October 2024 by a woman who used the shots between 2005 and 2021. Multiple lawsuits followed and, as of September 2025, over 800 of these claims had been consolidated in a multidistrict litigation (MDL), a type of litigation similar to a class action lawsuit.⁷

According to Sokolove Law, a national personal injury law firm actively recruiting and representing plaintiffs in Depo-Provera lawsuits, around a quarter of all sexually active women in the U.S. have used Depo-Provera at some point, putting a significant number of women at risk. “With millions of women worldwide relying on Depo-Provera for birth control—and nearly 25% of sexually active women aged 15 to 49 in the U.S. having used it—it’s vital that we take this risk seriously,” Virginia Buchanan, attorney with Levin Papantonio law firm, appointed Co-Chair of the Plaintiffs’ Executive Committee and as member of the Trial Subcommittee in the Depo-Provera multidistrict litigation told PEOPLE back in March. “Women deserve to have all the facts when making decisions about their health, especially when it comes to something as personal as birth control.” While Sokolove Law is helping connect and represent individual plaintiffs, Levin Papantonio is leading the multidistrict litigation in court as part of the official leadership team.^{1 7}

Reported Depo-Provera Injuries Include Stroke, Seizures, Cognitive Decline, and Inoperable Tumors

Chris Paulos, an attorney with the Levin Papantonio law firm who was appointed Plaintiffs’ Liaison Counsel in the Depo-Provera MDL told PEOPLE,

We have seen clients with stroke, seizure disorders, cognitive impairments and other damages. The surgery can be challenging as well, and some tumors are not operable due to their location and size.¹

Pfizer, which ​​was ordered to pay more than $2 million in Depo-Provera settlements for failure to properly warn users about the risk of bone mineral density loss, says the plaintiffs’ claims are “without merit,” adding that the company will “vigorously defend against these allegations.” In its statement, Pfizer also emphasized, “The Company stands behind the safety and efficacy of Depo-Provera, which has been used by millions of women worldwide and remains an important treatment option for women seeking to manage their reproductive health.”^{1 3 7}

Pfizer’s Public Denial Contrasts With Its Reported Attempt to Update FDA Labeling

Moreover, Pfizer claimed in court filings that it had proposed label changes to the FDA last year, but the agency reportedly rejected them. Pfizer’s simultaneous denial of any credible risk associated with its birth control shot and its alleged effort to pursue label changes with the FDA highlights a tension between the company’s public defense of Depo-Provera and its behind-the-scenes regulatory strategy.³

Ellen Relkin, an attorney with decades of experience in pharmaceutical litigation and now involved in the growing number of Depo-Provera lawsuits, argues that Pfizer’s approach was calculated and intentionally vague, calling it a “get-out-of-jail-free” card for the drugmaker. “It’s the new tool book to give a half-hearted, half-baked request to the FDA, hoping that it’s denied because of its inadequacy and then once they got the rejection, that’s their litigation defense.” Relkin added that Pfizer could have updated the label without Food and Drug Administration (FDA) approval. When asked by CBS Austin about Pfizer’s alleged request, the FDA responded: “We do not confirm or deny the existence of a submission. As such, we recommend you contact Pfizer regarding any request they may have made to the FDA.”^{3 7}

Relkin, along with other lawyers for the plaintiffs, said Pfizer had “substantial scientific evidence” since the 1980s that Depo-Provera could cause meningiomas but ignored it. “The law makes clear drug manufacturers like Pfizer are responsible for providing proper warnings to patients and doctors,” they said. Depo-Provera carries a black box warning—the FDA’s strongest safety label—generally issued when clinical trial data or post-marketing reports include deaths or other life-threatening events. In this case, however, the warning pertains specifically to the drug’s documented risk of bone mineral density loss—not to the potential for brain tumors.³

Depo-Provera Excluded from Group 1 Carcinogen Listing Despite Reported Breast Cancer Link

In 2008, the International Agency for Research on Cancer (IARC) classified both combined estrogen–progestogen and progestogen-only hormonal contraceptives as Group 1 carcinogens—the highest category, indicating there is “convincing evidence that [they] cause cancer in humans.” The report concluded there was “sufficient evidence” that these drugs can cause breast cancer, in-situ and invasive cancer of the uterine cervix, and liver cancer.⁸

Depo-Provera (depot medroxyprogesterone acetate, or DMPA) falls under the progestogen-only category, though the IARC evaluation focused mainly on combined estrogen–progestogen products. Still, existing research raises concerns that DMPA itself—beyond its association with meningioma—may also elevate cancer risk. A 2012 peer-reviewed analysis published in Contraception found that “recent DMPA use for 12 months or longer was associated with a 2.2-fold increased risk of invasive breast cancer” among women aged 20–44.^{8 9}

Because the 2007 IARC evaluation focused primarily on combined formulations, Depo-Provera was not included in the Group 1 classification despite evidence suggesting the injectable progestogen, like its oral counterparts, may also carry carcinogenic risks.⁸

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