Follicle-Stimulating Hormone (FSH): About This Test

What is it?

This test measures the amount of follicle-stimulating hormone (FSH) in a blood sample. This hormone is made by the pituitary gland.

• In women, FSH helps control the menstrual cycle and the production of eggs by the ovaries.
• In men, FSH helps control the production of sperm.

Why is this test done?

The amounts of FSH and other hormones are measured to:

• Find out why a couple can't become pregnant.
• Help diagnose menstrual problems or find out whether a woman has gone through menopause.
• See why a child is going through early or delayed puberty.
• Help diagnose certain pituitary gland problems, such as a tumor.

How do you prepare for the test?

Up to 4 weeks before the test, you may be asked to stop taking birth control pills or other medicines that contain estrogen or progesterone.

What happens during the test?

A health professional uses a needle to take a blood sample, usually from an arm.

For a woman who is having problems with her menstrual cycle or who cannot become pregnant, more than one blood sample may be needed to help identify a follicle-stimulating hormone (FSH) problem. A sample may be taken each day for several days in a row.

How long does the test take?

The test will take a few minutes.

What happens after the test?

• You will probably be able to go home right away, depending on the reason for the test.
• You can go back to your usual activities right away.