Factors such as older age, female sex, and exposure to three high-dose progestogens (nomegestrol, chlormadinone, and cyproterone acetate) are already known to increase the risk of meningioma.

This risk is much lower than that associated with other progestins, such as cyproterone acetate, chlormadinone acetate, and norgestrel.

Three associations of EE with a nontestosterone-derived progestin (CPA, chlormadinone acetate and drospirenone) are currently available and will be discussed in the 'Five-year view' section.