Lifespan's A - Z Health Information Library

An FSH test measures the amount of FSH (a hormone of the reproductive system) in the blood.

Blood is drawn from a vein, usually from the inside of the elbow or the back of the hand. The puncture site is cleaned with antiseptic, and an elastic band) is placed around the upper arm to apply pressure and restrict blood flow through the vein. This causes veins below the band to fill with blood.

A needle is inserted into the vein, and the blood is collected in an air-tight vial or a syringe. During the procedure, the band is removed to restore circulation. Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.

For an infant or young child:

The area is cleansed with antiseptic and punctured with a sharp needle or a lancet. The blood may be collected in a pipette (small glass tube), on a slide, onto a test strip, or into a small container. A bandage may be applied to the puncture site if there is any continued bleeding.

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.

This test may be performed when certain reproductive or pituitary disorders are suspected.

FSH is a hormone secreted from the anterior pituitary gland. In women, FSH stimulates production of ovarian follicles (eggs) and estradiol (another reproductive hormone) during the first half of the menstrual cycle. In men, FSH stimulates production of sperm in the testicular tubules.

• Male
  • prepubertal: 0-5.0 IU/L
  • pubertal: 0.3-10.0 IU/L
  • adult: 1.5-12.4 IU/L
• Female:
  • prepubertal: 0-5.0 IU/L
  • pubertal: 0.3-10.0 IU/L
  • follicular: 3.5-12.5 IU/L
  • mid-cycle: 4.7-21.5 IU/L
  • luteal: 1.7-7.7 IU/L
  • postmenopausal: 25.8-134.8 IU/L

Note: IU/L = international units per liter.

Disorders that may be associated with abnormal FSH results include:

• Hypopituitarism
• Klinefelter's syndrome
• Polycystic ovary disease
• Turner's syndrome
• Ovarian failure (ovarian hypofunction)

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

• Excessive bleeding
• Fainting or feeling lightheaded
• Hematoma (blood accumulating under the skin)
• Infection (a slight risk any time the skin is broken)
• Multiple punctures to locate veins

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.