FSH stands for follicle-stimulating hormone (FSH). This hormone is released by the anterior pituitary gland.

In women, FSH stimulates production of eggs and a hormone called estradiol during the first half of the menstrual cycle.

In men, FSH stimulates production of sperm.

This article discusses the test to check the level of FSH in the blood.

Follicle stimulating hormone

A blood sample is needed. For information on how this is done, see: Venipuncture

If you are a woman of childbearing age, your health care provider may want you to obtain the blood test on certain days of your menstrual cycle.

When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.

Your doctor may order this test if you have signs of certain reproductive or pituitary disorders. In some situations, it may also be done to confirm menopause.

The FSH test is usually done to help diagnose problems with sexual development, menstruation, and fertility. The test is used to help diagnose or evaluate:

• Menopause
• Women who have polycystic ovary syndrome, ovarian cysts, irregular vaginal bleeding, or infertility
• Children who start sexual development at a very young age
• Men who have infertility
• Men who do not have testicles or whose testicles are underdeveloped

Normal FSH levels will differ depending on a person's age and gender.

• Male
  • Before puberty: 0 - 5.0 mIU/ml*
  • During puberty: 0.3 - 10.0 mIU/ml
  • Adult: 1.5 - 12.4 mIU/ml
• Female:
  • Before puberty: 0 - 4.0 mIU/ml
  • During puberty: 0.3 - 10.0 mIU/ml
  • Women who are menstruating: 4.7 - 21.5 mIU/ml
  • Postmenopausal: 25.8 - 134.8 mIU/ml

The examples above are common measurements for results of these tests. Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your doctor about the meaning of your specific test results.

* mIU/ml = milli international units per milliliter

Disorders that may be associated with abnormal FSH results include:

• Hypopituitarism
• Klinefelter syndrome
• Polycystic ovary disease
• Turner syndrome
• Ovarian failure (ovarian hypofunction)
• Ovarian or adrenal cancers
• Precocious puberty in girls and boys
• Anorexia

The test may also be performed for:

• Anovulatory bleeding
• Multiple endocrine neoplasia (MEN) I
• Ovarian cysts

Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.

Other risks associated with having blood drawn are slight but may include:

• Excessive bleeding
• Fainting or feeling light-headed
• Hematoma (blood accumulating under the skin)
• Infection (a slight risk any time the skin is broken)

Lobo RA. Menopause: Endocrinology, consequences of estrogen deficiency, effects of hormone replacement therapy, treatment regimens. In: Katz VL, Lentz GM, Lobo RA, Gershenson DM, eds. Comprehensive Gynecology. 5th ed. Philadelphia, Pa:Mosby Elsevier;2007:chap 42.

Lobo RA. Primary and secondary amenorrhea and precocious puberty: etiology, diagnostic evaluation, management. In: Katz VL, Lentz GM, Lobo RA, Gershenson DM, eds. Comprehensive Gynecology. 5th ed. Philadelphia, Pa:Mosby Elsevier;2007:chap 38.

Melmed S, Kleinberg D, Ho K. Pituitary physiology and diagnostic evaluation. In: Kronenberg HM, Melmed S, Polonsky KS, Larsen PR, eds. Williams Textbook of Endocrinology. 12th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 8.