Definition

An estradiol test measures the amount of a hormone called estradiol in the blood. Estradiol is one of the main types of estrogens.

Alternative Names

E2 test

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
• Corticosteroids
• DHEA (a supplement)
• Estrogen
• Medicine to manage mental disorders (such as phenothiazine)
• Testosterone

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. Afterward, there may be some throbbing or a slight bruise. This soon goes 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 is also produced in other body tissues, such as skin, fat, cells bone, brain, and liver. Estradiol plays a role in:

• Growth of the womb (uterus), fallopian tubes, and vagina
• Breast development
• Changes of the outer genitals
• Distribution of body fat
• Menopause

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)

The test may also be ordered to check if:

• Hormone therapy is working for women in menopause
• A woman is responding to fertility treatment

The test may also be used to monitor people with hypopituitarism and women on certain fertility treatments.