Depo-Provera, a birth control injection, is the subject of a current lawsuit. Over 1,000 women allege that Pfizer did not adequately warn them about the risk of meningioma, a tumor in the brain lining, linked to the drug.
Medroxyprogesterone acetate (MPA), the active ingredient in Depo-Provera, was first synthesized in 1954. MPA is a synthetic hormone that mimics progesterone. Introduced in 1959, it was used to manage menstrual disorders, fibroids, endometriosis and certain cancers. By suppressing ovulation, it offers a more convenient alternative to traditional birth control, requiring only one injection every three months.
Clinical trials for Depo-Provera began in the 1960s and 1970s, often involving low-income women and those in developing countries. Many participants were not fully informed of potential side effects. Advocacy groups later criticized the lack of informed consent, particularly regarding risks such as menstrual irregularities, bone density loss and possible cancer links.
In 1974, the Food and Drug Administration (FDA) rejected Depo-Provera for contraceptive use due to concerns about long-term safety and potential cancer risks. However, MPA continued to be used for other medical conditions, such as endometriosis, and was approved as a contraceptive in other countries.
The FDA approved Depo-Provera as a contraceptive in 1992 after additional studies. According to Anapol Weiss, the approval included warnings about side effects such as bone mineral density loss, irregular bleeding and mood changes. Despite these warnings, the drug gained popularity due to its convenience.
In March 2024, a BMJ study examined the relationship between progestogen use and intracranial meningiomas. The study analyzed nearly 20,000 women who underwent meningioma surgery from 2009 to 2018. It found that prolonged use of certain progestogens, including MPA, increased the risk of meningiomas, with Depo-Provera users experiencing a 5.6-fold higher risk. Previous studies since 1983 have also indicated a link between progesterone and meningioma.
Following the study, Pfizer stated, “We are aware of this potential risk.” The findings raised widespread concern due to the drug’s use by millions of women over several decades.
In the fall, lawsuits were filed against Pfizer on behalf of women who developed meningioma after prolonged use of Depo-Provera. Given the drug’s widespread use, the litigation is expected to expand into a mass tort, allowing for individualized case details.
Recently, Pfizer requested dismissal of the lawsuit, stating it became aware of the risks in 2023. In February 2024, Pfizer applied to the FDA to add a warning to Depo-Provera’s label and to two pills with lower MPA doses. The FDA initially denied the request, stating, “the findings of the available observational studies alone do not support the addition of a warning on Meningioma risk to medroxyprogesterone acetate (MPA)-containing products.” Pfizer resubmitted its application in June 2025, and the label changes were approved.
Pfizer maintains its position on the safety and efficacy of Depo-Provera. However, countries such as Canada and the European Medicines Agency have added meningioma risk warnings. As of February 2026, over 2,098 claims have been consolidated in multidistrict litigation, which remains ongoing.
Women who received Depo-Provera and later developed meningioma should consider filing a lawsuit promptly, as claims must be filed within two to three years of diagnosis. Many law firms offer free case reviews.
