(13S,17R)-17-ethynyl-13-methyl-7,8,9,11,12,14,15,16-octahydro-6H-cyclopenta[a]phenanthrene-3,17-diol

DescriptionEthynyl estradiol (EE) is a synthetic form of estrogen that is majorly employed in numerous hormonal contraceptives in combination with progestins. Occasionally, it is also used as a constituent of menopausal hormone therapy with combination with progestins for treating menopausal symptoms. Previously, the drug was used solely for numerous indications such as treatment of prostate cancer and gynecological disorders. Ethynyl estradiol is a semisynthetic alkylated estradiol with a 17-alpha-ethinyl substitution. It is normally administred orally and is marketed mostly as a combination oral contraceptive under various brand names such as Alesse, Tri-cyclen, Yasmin, and Triphasil. A black box warning is normally labelled on the packaging that states that the drug should not be used in smoking women who are over 35 years old as it can lead to increased risk of serious cardiovascular side effects.

HistoryEthynyl estradiol was first developed in 1930 and officially introduced for medical used in 1943. In the 1960s, the drug was widely used in birth control pills. EE is currently found in most combined forms of birth control pills, which makes it one of the most used estrogens.

DescriptionEstrogens direct the development of the female genotype in embryogenesis and at puberty. Estradiol is the major estrogen secreted by the premenopausal ovary. Ethynyl estradiol is a synthetic analog of 17β-estradiol . A USP-approved grade of ethynyl estradiol is often formulated in combination with a progestin such as norgestrel /levonorgestrel or desogestrel and provided for use as an oral contraceptive. Efficacy of oral administration of ethynyl estradiol is facilitated by the ethynyl substitution at the C-17 position, which inhibits first pass hepatic metabolism. Ethynyl estradiol is also rapidly and almost completely absorbed from the gastrointestinal tract.

UsesA synthetic estradiol analog.

UsesA metabolite of 17a-Ethynylestradiol

UsesA synthetic steroid with high oral estrogenic potency

Usesestrogen, plus progestogen as oral contraceptive

General Description17 -Ethinyl estradiol has thegreatest advantage over other estradiol products of beingorally active. It is equal to estradiol in potency by injectionbut is 15 to 20 times more orally active. The primary metabolicpath for ethinyl estradiol is 2-hydroxylation bycytochrome P450 isozyme 3A4 (CYP3A4), followed byconversion to the 2- and 3-methyl ethers by catechol-Omethyltransferase.The 3-methyl ether of ethinyl estradiolis mestranol, USP, used in oral contraceptives. Mestranolis a prodrug that is 3-O-demethylated to the active ethinylestradiol. An oral dose of about 50 μg of mestranol has anestrogenic action approximately equivalent to 35 g oforal ethinyl estradiol. The demethylation is mainly mediatedby CYP2C9.