Test Quick Guide

Follicle-stimulating hormone (FSH) is a hormone associated with reproduction and the development of eggs in women and sperm in men. This test measures FSH in the blood.

FSH is made by the pituitary gland, a small organ located in the center of the head behind the sinus cavity at the base of the brain. Control of FSH production is a complex system involving the hypothalamus in the brain, the pituitary gland, and the hormones produced by the ovaries or testicles.

The hypothalamus releases gonadotropin-releasing hormone (GnRH), which stimulates the pituitary to release FSH and luteinizing hormone (LH), a closely-related hormone involved in reproduction.

Disorders affecting the hypothalamus, pituitary, and/or the ovaries or testicles can cause the production of too much or too little FSH, resulting in various conditions such as infertility, abnormal menstrual cycles, or early (precocious) or delayed puberty.

About the Test

Purpose of the test

The FSH test is used to evaluate fertility issues, the health of your reproductive organs (ovaries or testicles), or pituitary function. In children, it is utilized to evaluate early or delayed puberty.

What does the test measure?

The test for FSH may be used with other hormone tests such as LH, testosterone, estradiol, and/or progesterone to help:

  • Determine the cause of infertility
  • Diagnose conditions associated with dysfunction of the ovaries or testicles
  • Aid in the diagnosis of pituitary or hypothalamus disorders, which can affect FSH production

In women, FSH levels are also useful in:

  • The investigation of menstrual irregularities
  • Predicting when or if a woman is entering menopause

FSH levels help determine the reason for a low sperm count in men.

In children, FSH and LH help diagnose delayed or precocious (early) puberty. Irregular timing of puberty may be an indication of a more serious problem involving the hypothalamus, the pituitary gland, the ovaries or testicles, or other systems.

The measurement of LH and FSH may differentiate between normal patterns of development and true disease. Once it is established that symptoms are a result of true disease, further testing can identify the underlying cause.

When should I get this test?

For a woman, an FSH test may be ordered when she is having difficulty getting pregnant, has irregular or absent menstrual periods, or sometimes when it is suspected that she has entered menopause.

The test may be ordered when a man’s partner cannot get pregnant, when the man has a low sperm count, or when he has low muscle mass or decreased sex drive, for example.

In both women and men, testing may be ordered when a health care practitioner suspects a pituitary disorder is present. This can affect the production of several different hormones, so there may be signs and symptoms in addition to some of those listed above. They can include fatigue, weakness, unexplained weight loss, and decreased appetite, to name a few.

In children, FSH and LH may be ordered when a boy or girl does not appear to be entering puberty at an appropriate age (either too late or too soon). Signs of puberty may include:

  • Breast enlargement in girls
  • Growth of pubic hair
  • Growth of the testicles and penis in boys
  • Beginning of menstruation in girls

Finding a Follicle-stimulating Hormone Test

How can I get a follicle-stimulating hormone test?

FSH testing is usually performed at a doctor’s office or another medical setting like a hospital or lab. The tests are normally ordered by a doctor but may be available without orders from your doctor at a walk-in lab.

Can I take the test at home?

Yes. There is an FDA-approved self-test that measures the level of FSH in a urine sample. It is used as an indicator of menopause and perimenopause, which are associated with a rise in FSH levels. For more information, see this FDA website.

How much does the test cost?

The cost of an FSH test will vary depending on factors such as where the test is done and whether you have health insurance. When ordered by a doctor, insurance typically covers the test, although you may have to pay a copay or deductible. Your doctor’s office, lab, and health plan can provide information about any out-of-pocket costs that may be your responsibility.

Taking a Follicle-stimulating Hormone Test

The FSH test requires a blood sample, which is usually taken from your arm in a doctor’s office, health clinic, hospital, or lab.

Before the test

Usually, no special preparation is required for an FSH test. Your doctor will tell you if you must stop taking any medications or supplements before the test.

During the test

A blood sample is taken from a vein in your arm. The person taking the sample may tie a band around your upper arm and will clean the area where the needle will be inserted into your skin. A small amount of blood is drawn into a tube. You may feel a slight sting when the needle enters your skin.

The process of taking a blood sample usually takes less than three minutes.

After the test

At a doctor’s office or lab, you will be asked to apply gentle pressure to the site with a bandage or a piece of gauze after the needle is withdrawn. This will help stop bleeding and may prevent bruising. Next, the site will be bandaged. You may resume your normal activities following the test.

A blood draw is a very low-risk procedure. You may have slight bruising at the site where the blood sample was taken.

Follicle-stimulating Hormone Test Results

Receiving test results

The doctor who ordered your FSH test may share the results with you, or you may be able to access them through an online patient portal. FSH results are usually available within a few business days.

Interpreting test results

Results of an FSH test are typically considered with results of other hormone tests, such as LH, estrogens, and/or testosterone.

As part of an infertility workup, a high or low FSH is not diagnostic but provides a piece of information on what may be the cause. For example, a hormone imbalance may affect a woman’s menstrual cycle and/or ovulation. A health care practitioner will consider all the information from the workup to establish a diagnosis.

In women

FSH and LH levels can help differentiate between a condition affecting the ovaries themselves (primary) and dysfunction of the ovaries due to disorders of either the pituitary or the hypothalamus (secondary).

High levels of FSH and LH are consistent with conditions affecting the ovaries themselves. Some examples include:

Developmental defects:

  • Failure to develop ovaries (ovarian agenesis)
  • Chromosome disorder, such as Turner syndrome
  • Defects in the steroid production by the ovaries, such as 17 alpha-hydroxylase deficiency

Damage to the ovaries due to:

  • Radiation exposure
  • Chemotherapy
  • Autoimmune disease

Underlying conditions that affect ovary function, such as:

  • Polycystic ovary syndrome (PCOS)
  • Adrenal disease
  • Thyroid disease
  • Ovarian tumor

When a woman enters menopause, and her ovaries stop working, FSH levels will rise.

Low levels of FSH and LH are consistent with a pituitary disorder or problem with the hypothalamus.

And low FSH serum levels have been associated with an increased risk of ovarian cancer.

In men

High FSH levels are due to conditions affecting the testicles themselves. Some examples include:

  • Viral infection (mumps)
  • Trauma, injury
  • Radiation exposure
  • Chemotherapy
  • Autoimmune disease
  • Germ cell tumor
  • Failure to develop normal gonads (gonadal agenesis)
  • Chromosome disorder, such as Klinefelter’s syndrome

Low levels are consistent with pituitary or hypothalamic disorders.

In children

Higher levels of FSH and LH than expected for age, plus the development of secondary sexual characteristics at an unusually young age, indicate early puberty. This is much more common in girls than in boys. Usually, this premature development is due to a problem with the central nervous system and can have a few different underlying causes. Examples include:

  • Central nervous system tumor
  • Brain injury, trauma
  • Inflammation within the central nervous system (e.g., meningitis, encephalitis)

Normal prepubescent levels of LH and FSH in children exhibiting some signs of puberty may indicate a condition called “peripheral precocious puberty.” Elevated levels of the hormones estrogen or testosterone bring on the signs and symptoms. This may be caused by:

  • Tumors that produce and release hormones
  • Adrenal gland tumors
  • Ovarian tumors or cysts
  • Testicular tumors

Normal FSH and LH levels with a few signs of puberty (e.g., development of pubic hair and acne) may signal a previous environmental exposure to agents, such as testosterone cream or gel, or may be a normal variation of puberty.

In delayed puberty, LH and FSH levels can be normal or below what is expected for youth within this age range. Examples of some causes of delayed puberty include:

  • Dysfunction of the ovaries or testicles
  • Hormone deficiency
  • Turner syndrome
  • Klinefelter’s syndrome
  • Chronic infections
  • Cancer
  • Eating disorder (anorexia nervosa)

You may want to ask your doctor the following questions:

  • Can you make a diagnosis based on my FSH test results?
  • Do you recommend treatment or monitoring based on my FSH test results?
  • What follow-up tests will be ordered, and when will they take place?

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