Hormone Drugs Tied to Higher Risk of Brain Tumor, French Study Shows

A large French study has found that long-term use of certain hormone drugs known as progestogens may increase the risk of developing a type of brain tumor called an intracranial meningioma. The findings were published in The British Medical Journal (BMJ).

Researchers reviewed health records for more than 18,000 French women who underwent surgery for meningioma between 2009 and 2018, comparing them with about 90,000 women of similar age and region who did not have the tumor. The study focused on synthetic forms of the hormone progesterone, which are used in contraceptives, hormone replacement therapy, and certain gynecological treatments.

Prolonged use (defined as one year or more) of several drugs showed a significant rise in risk:

• Medrogestone (Colprone, others): 3.5 times higher odds of meningioma (odds ratio 3.49; 95% CI 2.38–5.10).
• Injectable medroxyprogesterone acetate (Depo-Provera, others): odds ratio 5.55 (95% CI 2.27–13.56).
• Oral promegestone (Surgestone): odds ratio 2.39 (95% CI 1.85–3.09).

No elevated risk was seen with natural progesterone, dydrogesterone, or the levonorgestrel intrauterine system (commonly used in hormonal IUDs).

Dr. Mangesh Thorat of the Wolfson Institute of Population Health said, “This large study using French national database confirms association (sic) between certain progestogens and meningioma risk. These results however do not give any reasons for women using progestogens to panic.”

Researchers emphasized that the study shows correlation, not causation, and that data limitations—such as lack of information on medical history, reasons for prescriptions, or radiation exposure—mean more research is needed before drawing firm conclusions.

This study adds to a growing body of research urging closer review of hormonal birth control safety. Other studies have linked certain oral contraceptives and hormonal IUDs to higher risks of blood clots, stroke, and breast cancer, particularly among women who smoke, have high blood pressure, or use high-dose estrogen combinations.

Hormonal birth control has also been linked to depression, anxiety, mood swings, crying easily or crying spells, irritability, being prescribed anti-depressants, an increased risk of suicide and chronic inflammation. A recent study also found that women on oral contraceptives had a markedly different inflammatory response to stress—what researchers called a more “male-typical” response—than normally-cycling women.

Despite this, experts say that for most healthy women, the benefits—effective pregnancy prevention, reduced menstrual pain, and lower risk of ovarian and endometrial cancers—still outweigh the risks. Ongoing monitoring and informed discussions with healthcare providers remain key to safe, individualized use.

Meningiomas are usually slow-growing tumors that form in the membranes surrounding the brain and spinal cord. While most are benign, they can still cause serious complications if they press on nearby tissue. Because millions of women worldwide use hormonal treatments, even small increases in risk could affect a large population. The authors of the study recommend continued research to better understand how dose, duration, and specific drug type influence outcomes.

Women taking progestogen-based drugs are advised not to stop treatment without medical supervision. Instead, patients should talk with their doctors about their medication history, review available alternatives, and balance the potential risks with their individual health needs.

Long-term use of certain progestogen hormone drugs appears linked to an increased risk of brain tumors, though the absolute risk remains small. The findings call for informed discussion between women and their healthcare providers—but not alarm, according to experts. However, these findings add another degree of caution to the casual use of these “safe and effective” medications.