What Is a Follicle-Stimulating Hormone Test?

FSH levels obtained from a blood or urine test help doctors find causes of fertility problems.

If you have trouble getting pregnant or have problems with your ovaries or testicles, your doctor may want you to have a follicle-stimulating hormone (FSH) test.

FSH is a hormone made by your pituitary gland, a grape-sized organ that sits at the base of your brain. It helps women maintain healthy eggs and get pregnant. The hormone keeps men’s sperm healthy.

Your doctor may order an FSH test to learn if your body is making too much or too little of the hormone. This can help the doctor see whether your fertility problem is due to an issue with your pituitary gland, your ovaries, or your testicles.

Here is information you can use to better understand what an FSH test is, why it’s important, and what you can expect.

If you’re a woman, you might get an FSH test if you:

• Are having trouble getting pregnant
• Have irregular periods
• Stopped having periods

If you’re a man, you might get an FSH test if:

• Your partner can’t get pregnant
• You have a low sperm count, low muscle mass, or low desire for sex

Children might get an FSH test if puberty starts too late or too early.

For women, the result of your FSH test will vary based on where you are in your menstrual cycle. Because of that, your doctor will ask about your period and suggest that you take the FSH test at a certain time of the month.

Tell your doctor if you’re pregnant since that also will change your test outcome.

Your doctor will want to know all the drugs you currently take. Some prescribed medicines, such as birth control pills, can skew your results.

A health professional will draw blood from a vein in your arm and send it to a lab. In some cases, you might provide a urine (pee) sample instead. Because FSH levels go up and down so much, you may need to collect all of your pee over the course of 24 hours.

The Food and Drug Administration (FDA) has approved an at-home FSH urine test for women. But you still need to follow up with your doctor afterward for complete results. The test may signal that you’re in or close to menopause (the end of your periods). But the at-home test can’t give you information about your fertility.

Does the FSH Test Pose Any Health Risks?

The FSH blood test is safe. But like any time you have blood work done, you may:

• Feel faint or lightheaded
• Have a bruise, lump, or soreness where the needle went into your skin

An FSH test doesn’t come out “positive” or “negative.” Instead, it reveals the amount of FSH you have, measured in international units per millimeter (IU/mL).

For women, results vary based on where you are in your monthly cycle.

Normal results are:

• Before release of an egg: 1.4 to 9.9 IU/mL
• At egg release: 6.2 to 17.2 IU/mL
• After egg release: 1.1 to 9.2 IU/mL
• After menopause: 19 to 100 IU/mL

For men, normal results can range from 1.4 to 15.5 IU/mL

Many things like your age, gender, and health history can affect your FSH test result. Because of that, you’ll need to rely on your doctor to explain what your number means. You may need more tests to check other hormones that are important for fertility. Together, these test results can give you and your doctor a clearer picture of what’s going on with your health.