An estradiol test measures the amount of a hormone called estradiol in the blood.
How the test is performed
A blood sample is needed.
How to prepare for the test
Your health care provider may tell you to temporarily stop taking certain medicines that may affect test results. Be sure to tell your provider about all the medicines you take. These include:
Birth control pills
Antibiotics such as ampicillin or tetracycline
DHEA (a supplement)
Medicine to manage mental disorders (such as phenothiazine)
Do not stop taking any medicine before talking to your doctor.
How the test will feel
When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging sensation. Afterward, there may be some throbbing or a slight bruise. These soon go away.
Why the test is performed
In women, most estradiol is released from the ovaries and adrenal glands. It is also released by the placenta during pregnancy. Estradiol plays a role in:
Growth of the womb (uterus), fallopian tubes, and vagina
Changes of the outer genitals
Distribution of body fat
In men, a small amount of estradiol is mainly released by the testes. Estradiol helps prevent sperm from dying too early.
This test may be ordered to check:
How well your ovaries, placenta, or adrenal glands work
If you have signs of an ovarian tumor
If male or female body characteristics are not developing normally
If your periods have stopped (levels of estradiol vary, depending on the time of month)
Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.
Other risks associated with having blood drawn are slight but may include:
Fainting or feeling light-headed
Hematoma (blood accumulating under the skin)
Infection (a slight risk any time the skin is broken)
Borawski D, Bluth MH. Reproductive function and pregnancy. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 22nd ed. Philadelphia, Pa: Elsevier Saunders; 2011:chap 25.
Gruber HA, Farag AF. Evaluation of endocrine function. In: McPherson RA, Pincus MR, eds. Henry’s Clinical Diagnosis and Management by Laboratory Methods. 22nd ed. Philadelphia, Pa: Elsevier Saunders; 2011:chap 24.
Susan Storck, MD, FACOG, Chief, Eastside Department of Obstetrics and Gynecology, Group Health Cooperative of Puget Sound, Bellevue, Washington; Clinical Teaching Faculty, Department of Obstetrics and Gynecology, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Bethanne Black, and the A.D.A.M. Editorial team.