A widely prescribed contraceptive injection, Depo-Provera, has been linked to a significantly increased risk of meningioma, a common type of brain tumor, according to a growing body of international research. The findings, now backed by three major studies in just over a year, are intensifying calls for transparency, better patient information, and legal accountability from pharmaceutical manufacturers.
What Is Depo-Provera?
Depo-Provera (medroxyprogesterone acetate) is a hormonal contraceptive injection administered every 12 weeks to prevent ovulation. It has been approved for use on the NHS for more than 40 years and is issued roughly 10,000 times per month in England.
Despite its convenience and effectiveness, new research highlights a serious safety concern for long-term users.
What the New Study Found
In the most recent study published in Expert Opinion on Drug Safety, researchers from the University of British Columbia analyzed medical records of:
- 72,181 women using Depo-Provera
- 247,000 women on oral contraceptives
Key Findings:
- Women on Depo-Provera were 3.5 times more likely to develop meningioma than those on the Pill.
- The elevated risk did not increase with longer duration beyond 12 months.
- The findings align with two previous studies:
- A 2024 BMJ study from France found up to 5x higher risk
- A 2023 study from the University of Alabama echoed the same concerns
Understanding Meningioma
A meningioma is a typically non-cancerous tumor that arises from the membranes surrounding the brain and spinal cord. While often slow-growing, they can become dangerous by compressing nerves or brain tissue, leading to:
- Headaches
- Blurred vision
- Hearing loss
- Difficulty swallowing
- Poor sense of smell
Roughly 2,000 to 3,000 cases are diagnosed annually in the UK, with women disproportionately affected.
The Suspected Link: Progestogen
Depo-Provera contains synthetic progestogen, which researchers believe may stimulate growth of meningioma cells by binding to progesterone receptors found in these tumors. While oral contraceptives containing progestogen have also been linked to increased risk, the association appears weaker and mostly in women who use them for five years or more.
Legal Action Brewing
In the UK:
- Hundreds of women are reportedly exploring legal action against Pfizer, alleging the company failed to warn users about the risks.
In the US:
- A class-action lawsuit is underway involving over 500 women, targeting Pfizer and other generic manufacturers.
- Plaintiffs claim the companies knew about the risks and failed to properly inform users or offer safer alternatives.
Regulatory Response
In response to accumulating evidence:
- The MHRA (UK’s drug safety watchdog) in October 2024 requested that Pfizer add a warning to patient leaflets.
- Pfizer has also written to NHS doctors advising that women diagnosed with meningioma stop using Depo-Provera immediately.
What Experts Say
“I do believe the evidence is now robust, with three large studies showing pretty much the same thing,”
said Dr. Mahyar Etminan, lead researcher on the Canadian study.
He added,
“Women concerned about this risk may want to consider opting for alternative contraceptives.”
Meanwhile, Virginia Buchanan, the attorney leading the US legal case, stated:
“This new study reinforces the need for legal action against Pfizer… to bring justice for women who have never been warned.”
FAQs
Is meningioma cancerous?
Most meningiomas are benign, but they can be life-threatening if they grow large or are located near vital brain structures.
Should I stop using Depo-Provera?
If you’re concerned or have a history of brain tumors, speak with your GP immediately. Do not stop any medication without medical advice.
Are other contraceptives safer?
Some forms of hormonal contraception, especially those with lower doses or different hormone profiles, may pose lower risks, but individual risk factors vary.
