France's National Agency for the Safety of Medicines (ANSM) will begin sending letters on Monday, September 14, to 1.6 million women across the country who have used contraceptive pills containing desogestrel, warning them of a low but real risk of brain tumor.
The letter, revealed by the newspaper Le Parisien, opens by telling recipients that their doctor or midwife prescribed them a contraceptive containing 75 micrograms of desogestrel. It will reach women who have used pills containing this hormone within the past twelve months. The women were identified using reimbursement data from France's national health insurance system, Assurance Maladie.
Why the warning now
The information campaign follows a 2024 study by the Epi-Phare research group, which examined the risk of meningioma, a tumor that develops in the meninges, the membranes that surround the brain, in connection with contraceptives containing desogestrel or etonogestrel. The study found the risk was higher among women taking the 75 microgram dose of desogestrel.
Desogestrel and etonogestrel are progestins, active substances used in hormonal contraceptives. Desogestrel is found mainly in contraceptive pills, while etonogestrel is used in contraceptive implants and vaginal rings.
Which products are affected
Pharmacies sell desogestrel-based pills under the brand names Cerazette, Optimizette, Elfasette and Antigone, as well as generic versions made by the laboratories Biogaran, Cristers and Sandoz. Etonogestrel is found in the pills Desobel, Mercilon, Varnoline and Varnoline Continu, along with generics from Biogaran, EG Labo and Viatris.
The risk may also apply to the subcutaneous contraceptive implant Nexplanon and to vaginal rings combining desogestrel and ethinylestradiol, sold under the brand names Nuvaring and Etoring and as a generic version made by Viatris.
How the risk changes over time
According to the ANSM, the longer a woman takes the medication, the greater the likelihood that a meningioma will develop. The agency says the risk becomes significant after five years of use and doubles after seven years. However, the elevated risk disappears one year after a woman stops taking desogestrel.
The health agency sought to reassure patients, noting that the large majority of meningiomas are not cancerous. Even so, it said they can cause serious complications that may require major, high-risk brain surgery. Roughly nine to ten new cases of meningioma are recorded each year for every 100,000 patients, the agency said.
Warning signs to watch for
The ANSM listed the early warning signs as headaches, visual disturbances, tinnitus, loss of smell, memory loss and weakness in the arms or legs. Women who experience these symptoms are advised to have a brain MRI.
Should women stop taking the pill?
The ANSM was clear that women should not stop their contraception abruptly. The agency warned that suddenly stopping contraception exposes a woman to the risk of an unplanned pregnancy. Any woman who wants to stop or change her contraceptive method should first speak with her doctor or midwife.
What doctors were told
Doctors and midwives were first informed of the meningioma risk linked to desogestrel-based contraception by email in June 2025, and then by letter in August 2026. They received a further letter in September 2026 containing the names of their own patients who are affected.
