About Ethinyl estradiol Synthetic Estrogen(a derivative of estradiol), In Combined oral contraceptive,Anti neoplastic. Mechanism of Action of Ethinyl estradiol The drug exerts it`s pharmacological action by binding to specific nuclear estrogen receptors present in target cells and regulating protein synthesis and thus producing desired therapeutic effects. Estrogen receptors are found in female sex organs, breast, pituitary, liver, bone, blood vessels, heart, CNS, hormone sensitive breast carcinoma cells, hormone responsive prostate carcinoma cells. Agonist binding to ligand binding domain of these receptors results in receptor dimerization and interaction with "estrogen response elements" of target genes and thus promotes gene transcription- through certain coactivator proteins which ultimately leads to modification of protein synthesis. It causes growth and development of female sex organs, maintains proper female sexual functioning. It exerts week anabolic action,