A new study published in JAMA Neurology in September 2025 has found a significant association between long-term use of the birth control shot Depo-Provera (depot medroxyprogesterone acetate, or DMPA) and an increased risk of developing meningioma, a type of brain tumor that forms in the membranes surrounding the brain and spinal cord.
Key Findings from the Study
Researchers from Cleveland Clinic and Case Western Reserve University analyzed medical records from more than 10 million women across 68 U.S. health care systems between 2004 and 2024 to assess how different forms of hormonal contraception impact brain tumor risk.
The study revealed:
- Women who used Depo-Provera had a 2.43 times higher relative risk of being diagnosed with meningioma compared to women who did not use hormonal contraceptives.
- The risk was most pronounced among women who used Depo-Provera for more than four years or started after age 31.
- Users of oral medroxyprogesterone acetate experienced a more modest but still elevated risk (1.18 times higher).
- Other contraceptives, including IUDs, combined oral contraceptives, and progestin-only pills, did not show increased risk.
Importantly, the number needed to harm (NNH) for Depo-Provera was calculated at 1,152 – meaning one additional meningioma case per 1,152 users. For oral medroxyprogesterone acetate, the NNH was 3,020.
These findings underscore the importance of informed decision-making and risk communication, particularly for women considering or currently using long-term injectable contraception.
A Growing Body of International Research
This U.S.-based research aligns with earlier global findings. In March 2024, a study from the National Agency for Medicines and Health Products Safety in France published in The BMJ linked several progestogen medications, including medroxyprogesterone acetate, to an increased risk of intracranial meningiomas.
The French study raised international awareness, and the new U.S. study provides corroborating evidence of these neurological risks among American women.
Depo-Provera Lawsuits and Ongoing Litigation
Mounting medical evidence has also prompted lawsuits against Pfizer, the manufacturer of Depo-Provera. Plaintiffs allege that the company failed to adequately warn users about the potential risk of brain tumors linked to long-term use of the drug.
As of September 2025, these cases have been consolidated in a federal multidistrict litigation (MDL), enabling coordinated discovery and pretrial proceedings. National firms such as Levin Papantonio Rafferty are currently leading the charge in representing plaintiffs across the country.
The outcome of this MDL could significantly shape future pharmaceutical risk disclosures and litigation strategies involving hormonal contraceptives.
Implications for the Legal Community
For attorneys, this litigation represents a rapidly evolving mass tort landscape with growing medical and regulatory attention. The strong statistical signal demonstrated in this new JAMA Neurology study may bolster causation arguments, strengthen expert testimony, and influence settlement dynamics as the MDL progresses.
Join the Legal Effort
Blue Sky Legal is actively monitoring developments in the Depo-Provera meningioma litigation and collaborating with legal teams nationwide.
If your firm is handling, or considering joining, Depo-Provera brain tumor cases, contact Blue Sky Legal to explore strategic partnerships, case evaluation support, and coordinated litigation efforts.
Together, we can help shape the future of pharmaceutical accountability and secure justice for those affected.
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