Pfizer Faces 400 Lawsuits Over Depo-Provera Brain Tumor Risk

Pfizer is facing a class-action lawsuit from nearly 400 women who allege that the widely used contraceptive injection Depo-Provera caused them to develop meningiomas (brain tumors). The plaintiffs claim Pfizer failed to adequately warn American users about the risks, despite evidence linking long-term use of the drug to a 5.6-fold increase in brain tumor risk.

A 2024 study published in the British Medical Journal (BMJ) revealed that using Depo-Provera—a progestogen-based contraceptive—for over a year significantly increases the risk of meningiomas. The research, led by EPI-PHARE, analyzed data from 108,366 French women between 2009 and 2018, with 18,061 having undergone brain tumor surgery. The findings clearly established a causal link between long-term use of DMPA (medroxyprogesterone acetate) in Depo-Provera and a heightened risk of intracranial tumors.

While Pfizer implemented meningioma warnings on Depo-Provera labels in Canada, Europe, South Africa, and the UK as early as 2015, the company has been accused of ignoring similar label updates in the US market. Plaintiffs argue this violates the principle of global drug safety consistency.

Originally developed by Upjohn in the 1950s as an anti-cancer drug, Depo-Provera was repurposed as a contraceptive in the 1960s and is now sold in over 70 countries. However, the drug’s active ingredient, DMPA, showed carcinogenic potential in animal studies, and early clinical trials in the US—conducted on 11,000 predominantly poor, African American women in Atlanta from 1967 to 1978—were later exposed for ethical violations. The FDA denied Depo-Provera’s approval three times before finally approving it in 1992.

Lawyers for the plaintiffs assert that Pfizer knowingly withheld critical safety information from American users, prioritizing profits over patient safety. This lawsuit could not only damage Pfizer’s reputation but also reignite scrutiny over the ethical practices in historical contraceptive research.