Two European research studies are ‘saying the quiet part out loud’ about progestin-only birth control’s ability to cause benign brain tumors.

Thousands of American women have joined a class-action lawsuit against the manufacturers of birth control shot Depo Provera, following 2024 research linking its use to a more than fivefold increased risk of developing a meningioma, a tumor in the meninges (the protective membranes covering the spinal cord and brain).

But while risk may be highest with Depo Provera use, research is increasingly linking multiple forms of progestin-only birth control – not just the birth control shot – with meningiomas. 

Key Takeaways:

• While meningiomas are largely not cancerous, they can still cause significant health issues.

• Progestin exposure can feed meningioma growth. However, though meningioma risk is increased, even significantly, with progestin use, the overall risk of an individual woman developing meningioma is still very low.

• Risk appears to be highest with use of Depo Provera. A 2025 French study showed that use of the main ingredient in the Depo shot for one year or longer had a fivefold-increased risk compared to women who did not get the shot. 

The Details:

If meningiomas aren’t cancerous, what’s the problem?

The majority of the time, meningiomas are slow-growing and not cancerous, so why the concern over their link with Depo Provera and other progestin-only birth control? The reason is because even though they are benign about 90% of the time, these tumors are growing inside a fixed space. 

As they grow, they can cause pressure on the brain tissue and spinal cord, which may in turn cause symptoms severe enough to impact daily living and potentially require brain surgery or radiation. 

Symptoms may include seizures, trouble seeing, hearing, speaking, and/or remembering things, along with numbness and weakness. What’s more, meningiomas can come back. 

Context on the connection between meningiomas and progestin-containing birth control

Four things are worth noting for context:

• Progestin exposure can feed meningioma growth (so can progesterone exposure during pregnancy). Conversely, reducing progestin or progesterone exposure (like stopping progestin-containing birth control or giving birth) can stop growth or even reduce tumor size. 

• A progestin-only birth control pill, known by the brand name Opill, is available over the counter here in the United States. The public generally expects medicines available without a prescription to be safer than those medicines that do require a doctor’s office visit and follow-up or ongoing monitoring. But progestin-only Opill is not without risks, including increased risk of heart attacks, strokes, and breast cancer compared to women not taking hormonal contraception.  

• We may think progestin-only birth control refers to one kind of drug, especially because progestin-only oral contraception is often referred to as ‘the mini-pill.’ But there are multiple generations of synthetic progesterone, known as progestin. For this reason, when we talk about progestin-only birth control, we’re potentially talking about multiple different kinds of progestin. The types of progestin sold here in the U.S. are not necessarily the same kinds that are used in European birth control. 

• When we talk about meningioma risk being increased, even significantly increased with exposure to certain progestins, we’re still talking about very low overall risk of an individual woman developing meningioma. According to ACOG, one in 2,000 women using the Depo Provera shot may experience meningioma, compared to one in 10,000 women not using Depo. 

What new research tells us about progestin-only birth control and meningioma risk

The 2025 French study

A 2025 French study of over 18,000 women who had meningioma surgery found that those who used medroxyprogesterone, the main ingredient in the Depo shot, for one year or longer had a fivefold-increased risk compared to women who did not get the shot. 

Desogestrel – a progestin found together with estrogen in American birth control pills Azurette, Bekyree, Kariva, Pimtrea, Simliya, Viorele, and Volnea – was also linked with meningioma.

• After five years of taking desogestrel, women were 70% more likely to develop a meningioma than women not taking desogestrel.

• When women used desogestrel for seven years or more, risk was 150% higher compared to women who didn’t take desogestrel. 

The study further linked two kinds of high-dose oral progestins that are not used here in the U.S. with meningioma risk. Of note, use of the Levonorgestrel IUD (aka the progestin-only IUD), which is popular in the U.S., did not lead to increased risk.

Importantly, within one year of stopping any of these meningioma-linked progestins, risk of meningiomas returned to baseline. 

The 2026 Denmark study

Most recently, a 2026 study from Denmark spanned 25 years of health records and followed 1,473 women with meningiomas.

• Consistent with previous research, Depo Provera was the riskiest progestin. 

• Combination estrogen and desogestrel pills (mentioned above) were associated with slightly increased risk when used in the past year, as were combination estrogen and drospirenone pills, sold in the U.S. as Gianvi, Jasmiel, Lo-Zumandimine, Loryna, Nikki, Ocella, Syeda, Vestura, YAZ, Yasmin, Zarah, and Zumandimine. 

• While the French study of high-dose (52 mg) IUDs found no increased risk, the Denmark study did identify slightly increased risk with use of one year or longer. 

The Bottom Line:

While the connection between progestin-only hormonal contraception and benign brain tumor risk doesn’t mean that the average woman is at high risk, women still deserve to be informed about even small risks.

Even more, they deserve education about family planning options that don’t jeopardize their health and reproductive issue treatments that restore health rather than Band-Aiding symptoms or bypassing the woman’s reproductive system altogether.