Drug information of Ethinyl Estradiol

Ethinyl Estradiol

Drug group:

A semisynthetic alkylated estradiol with a 17-alpha-ethinylsubstitution. It has high estrogenic potency when administered orally and is often used as the estrogenic component in oral contraceptives.

Mechanism of effect

Estrogens diffuse into their target cells and interact with a protein receptor. Target cells include the female reproductive tract, the mammary gland, the hypothalamus, and the pituitary. Estrogens increase the hepatic synthesis of sex hormone binding globulin (SHBG), thyroid-binding globulin (TBG), and other serum proteins and suppress follicle-stimulating hormone (FSH) from the anterior pituitary.
This cascade is initiated by initially binding to the estrogen receptors. The combination of an estrogen with a progestin suppresses the hypothalamic-pituitary system, decreasing the secretion of gonadotropin-releasing hormone (GnRH).


Ethinyl estradiol is a synthetic derivative of the natural estrogen estradiol. It is one of two estrogens currently used in oral contraceptive pills.


Absorption Is Rapid and complete follows oral intake of ethinyl estradiol (bioavailability 43%). Protein binding Is 97%. Metabolism is Hepatic.
Quantitatively, the major metabolic pathway for ethinyl estradiol , both in rats and in humans, is aromatic hydroxylation, as it is for the natural estrogens.


Ethinylestradiol Tablets is an estrogen-only preparation of hormone replacement therapy (HRT) for oral administration.
• Post menopausal symptoms due to estrogen deficiency including prevention of postmenopausal osteoporosis : for initiation and continuation of treatment of postmenopausal symptoms, the lowest effective dose for the shortest duration should be used. The usual dose range is 1 to 2miligrams daily, usually on a cyclical basis (e.g., 3 weeks on and 1 week off).
• For women without a uterus, who did not have endometriosis diagnosed, it is not recommended to add a progestogen.
• In women with an intact uterus (or in endometriosis when endometrial foci may be present despite hysterectomy), where a progestogen is necessary, it should be added for at least 12-14 days every month/28 day cycle to reduce the risk to the endometrium.
• Therapy with Ethinyl estradiol Tablets may start at any time in women with established amenorrhoea or who are experiencing long intervals between spontaneous menses. In women who are menstruating, it is advised that therapy starts on the first day of bleeding. As Ethinyl estradiol Tablets are usually taken on a cyclical basis direct switching from other estrogen-only HRT preparations taken cyclically is possible.
• Palliative treatment of prostatic cancer: 15 miligrams to150 mg daily. Larger dose Ethinyl estradiol Tablets are available.
• Hormone replacement therapy for failure of ovarian development e.g. in patients with gonadal dysgenesis: 1 to 2 miligrams daily, usually on a cyclical basis. Initial estrogen therapy should be followed by combined estrogen/progestogen therapy.
• Disorders of menstruation: 1 to 2 miligrams daily from day 5 to day 25 of each cycle. A progestogen is given daily in addition, either throughout the cycle or from days 15 to 25 of the cycle.


Cigarette smoking increases the risk of serious cardiovascular side effects from ethinyl stradyol use . This risk increases with age and with the extent of smoking (in epidemiologic studies, 15 or more cigarettes per day was associated with a significantly increased risk) and is quite marked in women over 35 years of age. Women who use Ethinyl Estradiol should be strongly advised not to smoke.
The use of oral estrogenes is associated with increased risks of several serious conditions including venous and arterial thrombotic and thromboembolic events (such as myocardial infarction, thromboembolism, and stroke), hepatic neoplasia, gallbladder disease, and hypertension, although the risk of serious morbidity or mortality is very small in healthy women without underlying risk factors.
The risk of morbidity and mortality increases significantly in the presence of other underlying risk factors such as certain inherited or acquired thrombophilias, hypertension, hyperlipidemias, obesity, and diabetes.

Points of recommendation

To make sure this medicine is safe for you, tell your doctor if you have:
• If you have an allergy to this medicine or any other part of it.
• If you are allergic to any drugs like this one, any other drugs, foods, or other substances. Tell your doctor about the allergy and what signs you had, like rash; hives; itching; shortness of breath; wheezing; cough; swelling of face, lips, tongue, or throat; or any other signs.
• If you have had any of these health problems: Blood clots, blood clotting problem, breast cancer, diseased arteries in the brain, disease of a heart valve with problems, heart disease, chest pain caused by angina, heart attack, stroke, high blood pressure, high cholesterol, a pancreas problem (pancreatitis) due to high blood triglycerides, liver disease, liver tumor, very bad headache or migraine, diabetes that affects blood flow, or tumor where estrogen makes it grow.
• If you have had any of these health problems: Endometrial cancer, cancer of the cervix or vagina, or vaginal bleeding where the cause is not known.
• If you have surgery and need bedrest.
• If you turned yellow during pregnancy or with estrogen-based or hormone contraceptive use.
• If you are pregnant or may be pregnant. Do not take this medicine if you are pregnant.
• If you are breast-feeding or plan to breast-feed.
• Talk with your doctor if you will need to be still for long periods of time like long trips, bedrest after surgery, or illness. Not moving for long periods may raise your chance of blood clots.
Take with or without food. Take with food if it causes an upset stomach .
Do not use in children who have not had their first menstrual period.
If a dose is forgotten it should be taken as soon as it is remembered. If it is nearly time for the next dose then the patient should wait until then. Two doses should not be taken together. Forgetting a dose may increase the likelihood of break-through bleeding and spotting.

Pregnancy level


Related drugs

Estrogen cojugated

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