What Is a FSH Test?

Medically Reviewed by Minesh Khatri, MD on May 14, 2023
3 min read

This test checks how much of “FSH” (follicle-stimulating hormone) is in your blood or urine. It’s not enough to diagnose a condition, and you’ll probably take other hormone blood tests at the same time, if your doctor thinks you need them.

A hormone is a chemical that your body makes that controls an organ or certain things that your body does. FSH is one of the hormones that is involved in reproduction.

Both men and women make this hormone. It helps women release their eggs and men to make sperm. Not having enough of this hormone can make it harder to get pregnant. Or having too much of it can cause the same problem.

Your pituitary gland, which is located just below your brain, makes FSH and releases it into your bloodstream.

Your doctor may suggest this test for the following reasons:

  • Problems getting pregnant.
  • Irregular periods. For women, your period has stopped or isn’t happening when it should.
  • Menopause. The FSH test can help diagnose when women will naturally stop having their period, which usually happens after the age of 45.
  • Low sperm count. This could also include symptoms like lower sex drive or muscle mass.
  • Early or late puberty. For kids who start puberty earlier or later than normal, the hormone test is one way to tell if there’s a bigger problem involving the hypothalamus (area of the brain that controls the pituitary gland), the pituitary itself, ovaries, testicles, or other parts of your body.
  • Pituitary or hypothalamus disorders. Problems here can affect how much FSH is made in your body. Other symptoms include fatigue, weight loss, and lower appetite.

You don’t need to do anything special to prepare for this test.

There are two ways your doctor can check your FSH level.

Blood test: The most common method used, your doctor, physician assistant, or another health care worker would use a needle to take a small amount of blood from a vein in your arm. This might feel a bit uncomfortable, but it’s a very quick process. You may have some mild bruising in that area, but this should go away in a few days.

Urine test: Your doctor could ask you to give a pee sample or several over a 24-hour period. The 24-hour process gives a more accurate look at your FSH level, which can change throughout the day.

Your doctor should have the results after a day or two of having the test.

The results will be a number that measures FSH in what’s called “milli-international units per milliliter” (mlU/ML). The healthy range varies depending on your gender and age (and for women, where you are in your menstrual cycle or if you’re in menopause).

A high or low FSH level isn’t enough for your doctor to make any diagnosis.

Your doctor may also check your other hormone levels too, including:

Tell your doctor what medicines you take. Certain drugs -- including birth control and hormone treatments -- can lower your FSH levels. Drugs like cimetidine (Tagamet), clomiphene (Clomid, Serophene), digitalis, and levodopa can raise your FSH levels.