Pfizer Faces Lawsuits Over Alleged Link Between Depo-Provera and Brain Tumors

Pfizer Inc. is facing federal lawsuits from women who claim its birth control injection Depo-Provera caused them to develop brain tumors known as intracranial meningiomas. The cases have been consolidated before Judge M. Casey Rodgers in the Northern District of Florida as part of a new multidistrict litigation involving Depo-Provera and related products.

The suits were filed by women from Ohio and California who say they used Depo-Provera for years as prescribed, later developing tumors that required surgery or radiation. They argue that Pfizer and its affiliates failed to warn doctors and patients in the United States about the potential risk of tumor growth associated with long-term use of the hormone-based contraceptive.

Depo-Provera contains medroxyprogesterone acetate, a synthetic form of the hormone progesterone. The drug is injected every three months and has been used by millions of women for birth control and for treating endometriosis. Research has long shown that progesterone can affect tumor growth in the membranes surrounding the brain, but the women involved in the lawsuits say that Pfizer never updated its U.S. labeling to reflect this risk.

The complaints cite years of studies linking Depo-Provera to meningiomas, including a 2024 paper in the British Medical Journal that found women using the injection were more than five times as likely to develop the tumor as non-users. Regulators in Canada, the European Union, and the United Kingdom now list meningioma as a potential adverse reaction on product labels, and Pfizer issued similar safety communications to doctors in South Africa earlier this year. No such warning appears on the American label.

Under U.S. product liability law, a manufacturer must warn about known or reasonably knowable risks. The lawsuits claim Pfizer could have added a warning without prior approval from the Food and Drug Administration, using a process that allows immediate label changes when new safety information arises.

Pfizer also sells a lower-dose version of the same drug, Depo-SubQ Provera 104, which those bringing the suits say is safer and equally effective. They argue that the company should have promoted the lower-dose option more widely instead of continuing to sell the higher-dose injection without adequate warning.

Meningiomas are tumors that form in the tissue covering the brain and spinal cord. They are often benign but can cause serious complications when they press against brain structures, sometimes requiring surgery or radiation, and long-term monitoring.

The Depo-Provera litigation is still in its early stages. Once pre-trial proceedings are complete, individual cases will return to their home districts for trial unless settled or dismissed.

Pfizer has not yet filed a response in the new cases but has previously denied wrongdoing related to its contraceptive products.