What is a Progesterone Test?

A progesterone test is a blood test. It can help your doctor check on ovulation or possible fertility problems.

Your doctor may call it a “serum progesterone” test. By itself, it’s not enough to diagnose any particular problem. But it could help, along with other tests.

There are also home urine tests used to monitor ovulation. These are used to look for a possible surge of the LH hormone that triggers ovulation. Some tests check for the actual progesterone metabolite.

What Is Progesterone?

Progesterone is a hormone, which is something your body makes to help it work. Hormones help manage many things your body does, including getting pregnant.

Progesterone helps control your period and prepares your body to get pregnant, after you ovulate.

If you do get pregnant, additional amounts of progesterone are created, which, among other effects, helps prepare your breasts to eventually make milk.

If you don’t get pregnant, the level of progesterone in your body drops. This, then, helps trigger the beginning of your period.

What Happens in the Test?

The test is designed to tell you what your level of progesterone is at the time of your test. You don’t need to do anything to prepare. But it will help if you take note of when your last menstrual period started.

The test itself is simple. Your doctor, physician’s assistant, or another health care professional will insert a needle in a vein in one of your arms and take a bit of blood for testing in a lab.

Test Results

Your results may be one of these:

Progesterone levels don’t fluctuate regularly. This would be determined through multiple tests. If the tests shows that your progesterone levels don’t rise and fall on a monthly basis as they should, then you may not be ovulating or having regular periods. This could make it harder to get pregnant.

Low levels of progesterone: This could depend on when during your cycle the test was done. If the test shows a lower than normal level of progesterone, it could be due to:

  • Ovaries not working normally//Ovulation didn’t take place
  • Possible abnormal pregnancy

Progesterone within normal levels: Progesterone levels in a certain range can signal that you ovulated. The test should be conducted wither 18-24 days after the first day of your period or 7 days before your next expected period. There is a range of progesterone levels from the lab work that can indicate that you did ovulate, meaning that you likely released an egg that cycle.


Other tests

If your doctor has you take a progesterone test, it’s possible that you might also get:

  • Other blood tests to check on your ability to get pregnant
  • Home urine tests that look at progesterone byproducts as an indicator of ovulation
  • An ultrasound to measure the thickness of the lining of your uterus
  • A specific blood test, if you’re already pregnant, to figure out if there are problems with the pregnancy.
WebMD Medical Reference Reviewed by Traci C. Johnson, MD on April 24, 2020



University of Rochester Medical Center, Health Encyclopedia: “Progesterone.”

Lab Tests Online – American Association for Clinical Chemistry: “Progesterone.”

Hormone Health Network – The Endocrine Society: “What Does Progesterone Do?”

American Pregnancy Association – Promoting Pregnancy Wellness: “Understanding Ovulation.”

University of Michigan Comprehensive Cancer Center, Michigan Medicine: “Normal Ovarian Function.”

© 2020 WebMD, LLC. All rights reserved.