estetrol

Estetrol is a synthetic estrogen and a naturally occurring steroid hormone produced only during pregnancy by the fetal liver. It is used primarily in combination with drospirenone as an oral contraceptive to prevent pregnancy. Estetrol acts as an agonist of estrogen receptors (ERα and ERβ), with moderate affinity and selectivity for ERα over ERβ. Its mechanism involves suppression of ovulation through modulation of the hypothalamic-pituitary-gonadal axis. Compared to other estrogens like ethinylestradiol or estradiol, estetrol has lower receptor affinity but higher metabolic stability and favorable pharmacokinetics. It demonstrates high selectivity for estrogen receptors with minimal off-target activity on other steroid hormone receptors or cytochrome P450 enzymes[1][4]. The drug was developed by Mithra Pharmaceuticals and approved in combination products such as Nextstellis (with drospirenone) for contraception[1][3].

Brand names

DrovelisLydisilkaNextstellis

Other names

15α-hydroxyestriolEstétrolEstetrolumOestetrol