Depo-Provera is all over the news, and not in a good way. On October 1, 2024, the first Depo-Provera lawsuit was filed by Kristina Schmidt in the U.S. District Court, Northern District of California, against Pfizer, Inc. Ms. Schmidt was diagnosed with a brain tumor at the age of 37. She alleges she suffered side effects from years of Depo-Provera use, including intense headaches, dizziness, and vertigo. In 2022, she was diagnosed with Grade 1 and Grade 2 Sylvian fissure meningioma brain tumors.
In the first of what would be many, Ms. Schmidt’s lawsuit against Pfizer asserts that her tumor is a result of continued use of Depo-Provera injections. The suit claims that the active ingredient, medroxyprogesterone acetate (MPA), can encourage abnormal cell growth that leads to brain tumors. The lawsuit also accuses Pfizer of failing to provide proper warnings, defective design, and other allegations of consumer safety oversight.
As of June 1, 2025, 348 active cases are pending against Pfizer. The number climbs month over month, even as the defendant’s lawyers claim Pfizer cannot be sued under the state failure-to-warn laws because the FDA had previously rejected a proposed warning on the Depo-Provera label highlighting the risk of brain tumors. They claim federal law trumps any state claim.
As the courts fight motions and debate consolidation, questions linger about the truth behind meningioma brain tumors and whether Depo-Provera is responsible.
What is Depo-Provera?
Depo-Provera, a Pfizer-manufactured brand name for medroxyprogesterone acetate, is an injectable contraceptive administered every three months. It is often called the birth control shot. A Depo-Provera injection is administered every three months in the arm or buttock, and offers a long-acting, highly effective contraceptive solution. Provided the injections are done consistently, it eliminates the need for daily administration.
Depo-Provera comes in two forms: the standard Depo-Provera, a higher-dose injection administered into the muscle, and Depo-SubQ Provera 104, a lower-dose injection administered under the skin. Despite the different administration methods and dosages, both versions offer comparable benefits and carry similar risks.
It is estimated that between 2015 and 2019, 25.4% of sexually active women used Depo-Provera. The data indicates significantly higher usage rates among certain demographics. Specifically, 27.2% of Hispanic women and 41.2% of Black women used Depo-Provera within the timeframe.
Depo-Provera contains the synthetic hormone, progestin, which prevents pregnancy. Progestin primarily functions by stopping the release of eggs during ovulation and by making cervical mucus thicker, thus hindering sperm from reaching the egg. Additionally, it thickens the cervical mucus lining, further preventing sperm from entering the uterus.
When administered consistently, Depo-Provera has an efficacy rate of 99% in preventing pregnancy. While it was designed and approved as a contraceptive, it is also commonly prescribed for managing other gynecological conditions. It is also widely prescribed to treat various gynecological issues, most notably endometriosis, providing symptom relief.
How Does Depo-Provera Cause Meningioma?
Scientific research has led experts to suspect that Depo-Provera’s link to meningioma stems from its extremely high levels of synthetic progestin, which imitates progesterone’s effects. Meningiomas often possess hormone receptors, particularly for progesterone and estrogen, and exposure to these hormones may promote tumor development.
There is also a link between dose-response and meningiomas. The more doses of Depo-Provera administered, the higher the risk of developing meningiomas. Research released in The British Medical Journal indicated that women who have injected birth control for a year or more may experience a 5.5-fold increase in the risk of developing meningioma brain tumors.
Meningiomas are tumors that develop on the meninges, the membranes that protect the brain and spinal cord. While not brain tumors themselves, as explained by the Mayo Clinic, they exert pressure on adjacent brain tissue, nerves, and blood vessels.
These tumors typically grow slowly, often remaining asymptomatic for years. However, the potential impact on surrounding structures can lead to significant disabilities. Given their gradual development, immediate intervention isn’t always required; in some cases, monitoring will suffice.
Predominantly affecting women, meningiomas can occur at any age, although they are more frequently identified in older individuals.
The Studies Reveal the Truth
The first report on the meningioma risk was published in 1983 in the European Journal of Cancer and Clinical Oncology. The study discovered a significant concentration of progesterone receptors within meningioma cells. It was found that these cells contain a higher number of progesterone receptors than estrogen receptors. Over time, it was discovered that meningiomas, which are typically slow-growing, can be influenced by changes in progesterone levels.
Another study, published in 1991 in the Journal of Neurosurgery, explored the effects of mifepristone, an anti-progesterone agent, on meningiomas. Mifepristone hindered progesterone’s ability to bind to its receptors, preventing it from stimulating tumor growth. The evidence was obvious: progesterone plays a critical role in the development of meningiomas.
These studies sounded an alarm ignored by Pfizer. Research demonstrated that hormone-blocking treatment could serve as an option to treat and manage meningiomas. Thus, if blocking progesterone could drastically reduce tumor growth, why were pharmaceutical companies increasing the use of progesterone and synthetic progestins? The studies from 1983, 1991, and another 1990 study supported the argument that Depo-Provera could cause or exacerbate meningiomas.
Meningioma Brain Tumors: Grades, Symptoms & Risk Factors
Meningiomas, tumors developing in the brain’s protective membranes, are the most prevalent type of brain tumor, accounting for 40% of all reported cases.
Most meningiomas are non-cancerous, but a certain percentage are cancerous. They are categorized into three grades:
- Grade I: A non-cancerous meningioma that grows slowly and accounts for 8 out of 10 cases.
- Grade II: Also non-cancerous but faster growing, which makes treatment more difficult. Grade II tumors are atypical (with subtypes including atypical, clear cell, and chordoid). Each type exhibits cellular changes that pose a risk of recurrence and can require both surgery and radiation for treatment. Grade II meningiomas account for about 15% of all cases.
- Grade III: These meningiomas are malignant and grow fast and aggressively, accounting for about 2% of cases.
Meningiomas are most often detected through MRI scans, and many are discovered incidentally during these scans. Patients who do not exhibit symptoms are typically monitored rather than undergoing surgery. But if and when surgery is required, doctors will remove the whole tumor and part of the surrounding area as a precautionary measure.
Symptoms of meningioma include:
- Vision changes, such as double vision or blurring
- Headaches (worse in the morning)
- Hearing loss
- Ringing in the ears
- Memory loss
- Loss of smell
- Seizures
- Weakness in the arms or legs
- Trouble speaking
Some risk factors for meningioma include:
- Female hormones – some studies have found a link between breast cancer and meningioma risk related to the role of hormones
- Oral birth control and hormone replacement therapy
- Genetics – Neurofibromatosis 2 (a rare inherited nervous system condition) increases the risk of meningiomas and other brain tumors. Other genetic conditions associated with meningiomas include Gorlin syndrome, multiple endocrine neoplasia type 1 (MEN1), Turcot syndrome, Lynch syndrome, Li-Fraumeni syndrome, Cowden syndrome, and Von Hippel-Lindau disease.
- Obesity
- Ionizing radiation exposure – patients who have undergone radiation therapy are at a higher risk.
FDA Warnings About Depo-Provera
In 2004, the FDA mandated a “black box” warning for Depo-Provera. This warning specifically addresses bone mineral density loss, leading the FDA to advise against long-term use (exceeding two years) of Depo-Provera for birth control.
Currently, the FDA has not issued further guidance or warnings about Depo-Provera.
However, Pfizer has implemented label changes and warnings in the EU and UK. The EU label states:
“Meningioma: Meningiomas have been reported following long-term administration of progestogens, including medroxyprogesterone acetate. Depo-Provera should be discontinued if a meningioma is diagnosed. Caution is advised when recommending Depo-Provera to patients with a history of meningioma.”
A more forceful and unambiguous warning from Pfizer is essential for individuals considering or using Depo-Provera. The current weak warning is insufficient and essentially ineffective. It must be strengthened significantly to protect those using the hormone therapy.
Depo-Provera Lawsuits
Pfizer admitted in April 2024 to the connection between Depo-Provera and meningioma tumors via a press release. Despite this acknowledgment, they have not updated drug labels or information sheets. Based on strict liability for failure to warn, Pfizer could be held responsible for not properly advising patients and doctors of severe side effects, even if the drug itself is not flawed.
The first lawsuits were filed in October 2024. The plaintiffs brought suit against Pfizer and Pharmacia & Upjohn, alleging the Depo-Provera shots caused significant and life-altering injuries. One plaintiff started using Depo-Provera in 1995 and continued its use until 2018, completely unaware of the potential risks associated with prolonged use.
Lawsuits argue that Pfizer was aware, or should have been, of the elevated risk, and its resistance to updating the label is a clear failure to warn. Many will argue that Pfizer was prioritizing profits over people, as a warning label would likely have resulted in lower sales. The drug giant put a price on women’s health – a price they would never have to pay.
Who is Eligible to file a Depo-Provera Lawsuit?
Women who have had at least two injections of Depo-Provera birth control and have been diagnosed with meningioma are eligible to file a claim. There is a dose-response relationship, meaning that those who used Depo-Provera for longer periods likely have a stronger claim. However, it is believed that receiving the shot twice is enough to file a viable claim.
What Are Your Next Steps?
If you are experiencing any symptoms, please consult your healthcare provider for further evaluation and testing, especially if you have used or are using Depo-Provera.
Vogelzang Law is here to help. Please contact us with any questions or concerns, or if you need additional information. Our attorneys are on standby.
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