In September 2025, researchers from Case Western Reserve University and the Cleveland Clinic published a new study linking the Depo-Provera birth control shot with an increased risk of being diagnosed with a meningioma—a common type of brain tumor.
Featured in the prestigious medical journal JAMA Neurology, this is the third academic study to identify a connection between the Depo-Provera shot and meningiomas. The British Medical Journal was the first to establish this link in March 2024, and researchers published another study supporting the BMJ’s findings later that year in peer-reviewed oncology journal Cancers.
What were the results of the study?
To obtain their findings, researchers analyzed the medical data of over 10 million American women with a history of using contraceptives like the Depo-Provera shot. This data was collected from the TriNetX electronic health record registry, which includes unidentified medical records from 68 health care organizations in the United States.
According to the study, women who’ve received at least 1 injection are more likely to develop a meningioma compared to women who’ve never used Depo-Provera at all. However, women who’ve used the shot consistently for over 4 years—or started using Depo-Provera after turning 31 years old—are the most at-risk. Women in this high-risk category have a 243% increased chance of developing meningiomas compared to women who’ve never used Depo-Provera.
The number needed to harm (NNH) that researchers calculated was 1,152, which means 1 of every 1,152 patients in the study who used Depo-Provera were diagnosed with a meningioma. Women who only used the shot for 1-2 years were very unlikely to be affected, but women who used the shot for at least 4+ years were much more likely to receive a diagnosis.
There was no increased risk of developing a meningioma associated with any other type of contraceptive product, including pills, IUDs, and implants.
Will this study affect the Depo-Provera lawsuit?
Though researchers have already published multiple studies linking Depo-Provera to an increased risk of meningioma diagnosis, this particular study includes a treasure trove of new evidence that lawyers can use against Pfizer, the shot’s manufacturer.
Unlike the previous Depo-Provera studies from 2024, this new publication analyzed real-world data from millions of women, which has provided lawyers with a vast number of examples showing the health risks involved with the Depo-Provera shot. This additional data could likely play a large role in strengthening claims against Pfizer over time, especially as lawyers continue to file new cases for women who’ve been affected.
File a Depo-Provera claim
If you or a family member were diagnosed with a meningioma after getting at least one injection of Depo-Provera, you may be entitled to significant compensation from the lawsuit.
Ready for a free case review? Take our online Depo-Provera eligibility evaluation to see if you may be eligible to file a claim.
