New Study Adds to Evidence Depo-Provera Injections Cause Meningioma Brain Tumor Risks

Findings come as parties have reached a Depo-Provera lawsuit settlement to resolve thousands of brain tumor injury claims.

A new study adds to the evidence linking Depo-Provera to brain tumor growth, while raising concerns that similar risks may be associated with other hormonal birth control methods, including the Mirena IUD.

Researchers from Denmark published a study in JAMA Network Open on July 2, indicating they found evidence of increased risk of intracranial meningiomas associated with numerous kinds of birth control methods, including oral contraceptives, intrauterine devices (IUDs) and Depo-Provera shots. They also found similar risks with some hormone therapy products.

The common thread between all of the products was the hormone progesterone, which increased the risk of intracranial meningioma by 60% across the board.

Depo-Provera Brain Tumor Risks

Depo-Provera is a birth control injection that contains medroxyprogesterone acetate, which is a synthetic form of progesterone. It was approved by the U.S. Food and Drug Administration (FDA) in 1992, and is marketed as a long-term and safe birth control method that only requires an injection every three months. It has been used by tens of millions of women worldwide.

Findings from the latest study appear to support allegations raised in a growing number of Depo-Provera lawsuits filed by women who developed meningioma brain tumors. The complaints maintain that meningioma cells are particularly sensitive to progesterone because they contain numerous hormone receptors that may promote tumor growth.

The first wave of claims followed a 2024 study published in The BMJ, which found that prolonged Depo-Provera use was associated with a more than five-fold increased risk of intracranial meningioma. Those lawsuits, along with the thousands filed since, allege the tumors may require complex brain surgery and lifelong medical monitoring because they can recur after removal or continue growing when they cannot be safely removed.

Birth Control Brain Tumor Study

In the new study, researchers with the Danish Medicines Agency conducted a 25-year nationwide case-control study across the country of Denmark from January 1, 2000, to December 31, 2024, using data from the national registry. The researchers identified cases of meningioma and matched them with control cases with a similar age, birthplace and marital status, looking to see who used progesterone products and who did not.

The researchers found a total of 1,473 incidents of women diagnosed with intracranial meningioma, and matched them against 14,717 controls. According to their findings, the odds of a brain tumor increased 61% when the woman used any progesterone.

The data indicated that Depo-Provera injections increased the risk of brain tumors by four and a half times, which was easily the highest odds ratio found. However, smaller increases were seen with birth control pills containing drospirenone, like Yaz and Yasmin, progesterone-only pills like Slynd, and the Mirena IUD, the latter of which was linked to a 58% increased brain tumor risk.

“Medroxyprogesterone showed the highest risk with relatively low numbers needed to harm, whereas all combined oral contraceptives, oral progestogen-only contraceptives, and IUDs had relatively high numbers needed to harm, especially among the youngest women. However, the present study suggests an increased risk of meningioma for several progestogens not previously associated with meningioma.”

– Dr. Charlotte Wessel Skovlund, Data Analytics, Danish Medicines Agency

In addition, the researchers also found a 66% increased risk with cyproterone, which is a hormone therapy drug and not a contraceptive. They noted that there has been very little data collected on hormone therapy drugs and brain tumor risks.

According to the data, those risks generally disappeared after five years of discontinuation across progesterone products.

Depo-Provera Lawsuit Settlement

The findings emerged just after Pfizer Inc., Pharmacia LLC, Pharmacia & Upjohn Co. LLC and representatives of about 5,500 women announced they had reached a global Depo-Provera lawsuit settlement agreement last month.

The terms of the settlement have not yet been released, and the parties indicate not all of those details have yet been finalized. However, U.S. District Judge M. Casey Rodgers, who is overseeing the consolidated Depo-Provera Lawsuit multidistrict litigation (MDL) in the Northern District of Florida, has vacated all trial and pretrial deadlines for the first of five representative cases that were being prepared for bellwether trials.

Those trials, which were meant to give the parties an opportunity to see how juries responded to evidence and testimony common throughout the litigation, do not appear to be necessary at this point.

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