Health Encyclopedia

Follicle-Stimulating Hormone

Does this test have other names?


What is this test?

This test measures the level of follicle-stimulating hormone (FSH). FSH is an important hormone made in your pituitary gland.

Hormones are chemical messengers that travel through your blood. Your pituitary gland is located on the underside of your brain. FSH is made in the front part of your pituitary gland.

If you are a man, FSH travels to your testicles. There, it tells the cells in your testicles to make sperm. If you are a woman, FSH travels to your ovaries. There, it stimulate the growth of eggs during your menstrual cycle. In children, FSH is important for sexual development.

Why do I need this test?

You may need this test to find out if your pituitary gland is making too much or too little FSH. This test can help your healthcare provider tell whether problems you may be having are caused by your pituitary gland or by your ovaries or testicles. Some conditions that may be checked with this test include:

  • Ovarian failure in women

  • Testicular failure in men

  • Early or late puberty in children

  • Fertility problems in men and women

What other tests might I have along with this test?

Your healthcare provider may also order a blood test that measures another pituitary hormone called luteinizing hormone (LH). LH is also important for normal function of your testicles or ovaries. You may also have tests to measure other hormone levels.

What do my test results mean?

Many things may affect your lab test results. These include the method each lab uses to do the test. Even if your test results are different from the normal value, you may not have a problem. To learn what the results mean for you, talk with your healthcare provider.

FSH is measured in international units per milliliter (IU/mL). Normal results of this test for men are:

  • 1.24 to 7.8 IU/mL

If you are a woman, the normal results depend on where you are in your menstrual cycle. Your healthcare provider will help you understand the results. Normal results are:

  • 1.68 to 15 IU/mL (follicular phase)

  • 21.9 to 56.6  IU/mL (ovulatory peak)0.

  • 61 to 16.3 IU/mL (luteal phase)

  • 14.2 to 52.3 IU/mL after menopause

If this test is done for your child, a normal result will depend on how the test was done and what units of measurement were used.

Many conditions can cause your FSH to be too high or too low. Your provider will discuss the results of your blood test, what it means in your case, and whether you need more testing.

How is this test done?

The test requires a blood sample, which is drawn through a needle from a vein in your arm.

Does this test pose any risks?

Taking a blood sample with a needle carries risks that include bleeding, infection, bruising, or feeling dizzy. When the needle pricks your arm, you may feel a slight stinging sensation or pain. Afterward, the site may be slightly sore.

What might affect my test results?

Being pregnant or taking birth control pills may affect the results of this test. Several medicines may also affect the results.

How do I get ready for this test?

You don't need to prepare for this test. But be sure your healthcare provider knows about all medicines, herbs, vitamins, and supplements you are taking. This includes medicines that don't need a prescription and any illicit drugs you may use.


Medical Reviewers:

  • Hanrahan, John, MD
  • Sather, Rita, RN