NEW STUDY: Pfizer’s Birth Control Shot Used by 25% of U.S Women Linked to Disabling Brain Tumors

A massive study of 61 million women finds Depo-Provera increases risk of meningioma by 240% as criminal enterprise Pfizer faces a tsunami of lawsuits.

by Nicolas Hulscher, MPH

For decades, Pfizer has marketed its injectable birth control Depo-Provera as a convenient, long-acting option for women. What few were told — and what new research now confirms — is that this hormone shot doubles the risk of developing brain tumors.

The latest study, published in JAMA Neurology by researchers from the Cleveland Clinic and Case Western Reserve University, examined over 61 million U.S. medical records spanning two decades. Among these, women who used Depo-Provera — formally known as depot medroxyprogesterone acetate (DMPA) — were found to have a 2.4-fold higher risk of developing meningioma, a slow-growing but potentially disabling brain tumor.

Depo-Provera has been used by roughly 1 in 4 sexually active women in the United States — a staggering figure given the now-documented neurological danger. The study found the highest tumor risk in women who started injections after age 31 or continued for more than four years.

Though meningiomas are often labeled “benign,” their growth can compress vital brain structures, leading to vision loss, cognitive decline, seizures, and paralysis.

The Lawsuits and the Timeline of Deception

More than 1,000 women across the country have already filed suit against Pfizer, alleging that the company knew for decades about the potential for tumor formation yet failed to adequately warn users.

Evidence cited in the legal filings traces concerns back to 1980s studies linking synthetic progestins to brain tumor proliferation — long before the FDA finally approved Depo-Provera for contraception in 1992.

Notably, the FDA had initially rejected Pfizer’s application for contraceptive approval for nearly 40 years, citing cancer risks. When the product was finally approved, a “black box” warning was added years later — but only for bone-density loss, not for brain tumors.

In 2023, Pfizer quietly acknowledged to regulators that data showed a possible link between Depo-Provera and meningioma, yet claimed the evidence was “inconclusive.” The company’s motion to dismiss ongoing litigation argues that it had asked the FDA to update the label — an apparent attempt to shift responsibility to the agency itself. However, the corrupted FDA denied the labeling change because they claimed the available studies didn’t support the warning.

What This Means

The number needed to harm in the JAMA analysis was 1,152 — meaning that for every 1,152 women given Depo-Provera, one is expected to develop a meningioma attributable to the drug. Multiplied across millions of exposed users, the potential burden is enormous.

Once again, criminal enterprise Pfizer shows it’s true colors. From hormone injections to mRNA products, the same playbook repeats — profits first, patients last.

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Nicolas Hulscher, MPH

Epidemiologist and Foundation Administrator, McCullough Foundation

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