A new study has suggested that a widely used contraceptive pill could be linked to an increased risk of brain tumors.
The mini-pill, taken daily and often seen as a safer alternative to the combined pill, may increase the risk of developing a meningioma — a non-cancerous but potentially dangerous tumour that can press on the brain.
The pill in question contains a hormone called progesterone, and in particular, the type known as desogestrel has caught scientists’ attention, as reported by the Daily Mail.
While desogestrel is frequently prescribed for those who can't take oestrogen-based contraception, it’s now under scrutiny after researchers noticed a concerning pattern.
A team of French scientists analyzed medical records from over 8,000 women who had undergone surgery for meningioma — and many of them had been taking the desogestrel mini-pill for five years or more.
But before panic sets in, experts want women to know: the overall risk is still very low.
"The magnitude of increase in the risk [of meningioma] is small," said Dr Mangesh Thorat, an expert in population health at Queen Mary University of London.
He reassured patients that: "Short-term use [of the mini-pill] is not associated with increased risk and that the excess risk ceases to exist once the use is stopped for more than a year."
In fact, researchers writing in the British Medical Journal estimated that only one in every 67,000 women on desogestrel would develop a meningioma serious enough to need surgery.
And, crucially, the elevated risk was only found in those using it for five years or more — and disappeared entirely within a year of stopping.
So What Exactly Is a Meningioma?
It’s a tumour that forms in the lining of the brain. Over 90% are benign, meaning they won’t spread to other parts of the body.
But they’re still no joke — they can grow and press against brain tissue, leading to symptoms like headaches, vision issues, seizures, memory loss, and persistent nausea.
Surgery is often needed when they begin to cause increased pressure inside the skull.
“Common symptoms of a meningioma include a persistent headache as well as constant nausea which is often accompanied with drowsiness.”
The findings come hot on the heels of another scare.
Just weeks ago, hundreds of women in the UK began considering legal action after a separate study found that a contraceptive injection with similar hormones raised the same red flags.
Women who received the jab for over a year were found to be five times more likely to develop a meningioma.
With the mini-pill now under the microscope, health experts are calling for more research.
Dr Jyoti Thorat from the Institute of Cancer Research in London noted that the study only looked at one version of the mini-pill — desogestrel — and warned: “The findings could not be applied to all versions of the drug, particularly those not commonly prescribed in France.”
He called for further studies in other countries to better understand the global implications.
In the UK, around 6% of women aged 16 to 49 use the mini-pill. It works by thickening cervical mucus and thinning the womb lining, making it harder for sperm to reach an egg. In some women, it also prevents ovulation.
When taken perfectly, it’s more than 99% effective. But with everyday life (missed doses, illness), about 1 in 10 women could still become pregnant.
Side effects can include nausea, mood swings, breast tenderness, headaches, and in some cases, women report weight gain — although the NHS says there’s no hard evidence the pill actually causes that.
And there's more. A recent study also linked the mini-pill to a higher asthma risk: “Women with asthma who take the mini-pill may be a third more likely to suffer an attack,” according to research published just last month.