What is an estrogen test?

An estrogen test measures the level of estrogens usually in a sample of your blood, but sometimes in urine (pee).

Estrogens are a group of hormones that play a key role in female reproductive health, including puberty, menstruation, pregnancy, and menopause. Estrogens are also important for heart, bone, and brain health in males and females. But males need estrogen in much smaller amounts.

There are many types of estrogen, but only three types are commonly tested:

• Estrone, also called E1, is the only estrogen that females continue to make after menopause. Menopause is the time after menstrual periods have stopped for a year. Males and females make estrone in the adrenal glands (glands that sit on top of each kidney), and in body fat. In females, the ovaries (the glands that contain eggs) also make estrone.
• Estradiol, also called E2, is the main estrogen in nonpregnant females of childbearing age. It's mostly made in the ovaries and is important for fertility (the ability to get pregnant). It also helps support brain and bone health. Males make small amounts of this estrogen in the testicles (the glands that make sperm).
• Estriol, also called E3, is an estrogen that increases during pregnancy. The placenta (the organ that grows in the uterus to provide nutrients and oxygen to the unborn baby) makes estriol. Measuring estriol levels can help monitor the health of a pregnancy and the unborn baby. Males and nonpregnant females have very low levels of this estrogen.

Estrogen levels in females normally change a lot throughout life. In males, estrogen levels change much less. But levels that stay too high or too low may be a sign of a health problem.

Other names: estradiol test, estrone (E1), estradiol (E2), estriol (E3), estrogenic hormone test

What is it used for?

In females, estradiol and/or estrone testing may be used:

• To help diagnose conditions that may be caused by estrogen levels that are too high or too low, such as:
  • Early or late puberty
  • Menstrual problems or abnormal vaginal bleeding
  • Infertility (problems getting pregnant)
• To help monitor:
  • Infertility treatments
  • Hormone replacement therapy for menopause
  • Hormone treatment for certain cancers, such as breast cancer

• During pregnancy, an estriol hormone test may be used to:
  • Help diagnose certain birth defects
  • Monitor a high-risk pregnancy

• In males, estradiol and/or estrone tests may be used to see whether too much estrogen is causing conditions, such as:
  • Late puberty
  • Breast growth (gynecomastia)
  • Infertility
  • Erectile dysfunction (ED), problems having an erection

Why do I need an estrogen test?

If you are female, you may need estrogen testing if you:

• Have early or delayed puberty
• Are childbearing age and have abnormal periods or no periods at all
• Are having trouble getting pregnant
• Have a high-risk pregnancy
• Have symptoms of menopause, including hot flashes and/or night sweats
• Use hormone replacement therapy after menopause
• Have vaginal bleeding after menopause
• Have a tumor that may be making estrogen

If you're pregnant, you may have an estriol test between weeks 15 and 20 of your pregnancy. The test may be part of a group of prenatal tests called a triple screen test or a quad screening test. The test can check whether your baby has a high risk for a genetic birth defect such as Down syndrome. You may be more likely to have a baby with a birth defect if you:

• Have a family history of birth defects
• Are age 35 or older
• Have diabetes
• Have had a viral infection during pregnancy

If you are male, you may need estrogen testing if you have:

• Delayed puberty
• Enlarged breasts or other symptoms of too much estrogen
• Have a tumor that may be making estrogen

What happens during an estrogen test?

If you are tested at your provider's office or a lab, you will provide a blood or urine sample. If you use an at-home test, the sample is usually saliva (spit).

For a blood test: A health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.

For a urine test: You'll need to collect all your urine during a 24-hour period. This is called a 24-hour urine sample test. You will be given a special container to collect your urine and instructions on how to collect and store your samples. Your provider will tell you what time to start. The test generally includes the following steps:

• To begin, urinate in the toilet as usual. Do not collect this urine. Write down the time you urinated.
• For the next 24 hours, collect all your urine in the container.
• During the collection period, store the urine container in a refrigerator or in a cooler with ice.
• 24 hours after starting the test, try to urinate if you can. This is the last urine collection for the test.
• Return the container with your urine to your provider's office or the laboratory as instructed.

For an at-home saliva test: You'll collect a sample of saliva and send it to a lab for testing. Ask your provider which test is best to use. Be sure to follow all the instructions that come with your kit and discuss your results with your provider.

Will I need to do anything to prepare for the test?

You don't need any special preparations for an estrogen test.

Are there any risks to the test?

There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.

There is no known risk to a urine or saliva test.

What do the results mean?

Your test results will mean different things depending on:

• Your age
• Your sex
• The reasons for having the test
• The type of estrogen that was measured
• The results of other tests you may have had

Talk with your provider to find out what your results mean for your health. Because estrogen levels often change, you may need to be tested more than once to look for a trend in your estrogen levels over time.

Learn more about laboratory tests, reference ranges, and understanding results.