Follicle-Stimulating Hormone

This is a test to evaluate your pituitary function, especially in terms of fertility issues.

Follicle-stimulating hormone (FSH) is made by the pituitary gland in the brain. Control of FSH production is a complex system involving hormones produced by the gonads (ovaries or testes), the pituitary, and the hypothalamus, such as gonadotropin-releasing hormone.

In women, FSH stimulates the growth and maturation of ovarian follicles (eggs) during the follicular phase of the menstrual cycle. This cycle is divided into two phases, the follicular and the luteal, by a mid-cycle surge of FSH and luteinizing hormone (LH). Ovulation occurs shortly after this mid-cycle surge of hormones. During the follicular phase, FSH initiates the production of estradiol by the follicle, and the two hormones work together in the further development of the egg follicle. During the luteal phase, FSH stimulates the production of progesterone. Both estradiol and progesterone help the pituitary control the amount of FSH produced. FSH also facilitates the ability of the ovary to respond to LH. At the time of menopause, the ovaries stop functioning and FSH levels rise.

In men, FSH stimulates the testes to produce mature sperm and also promotes the production of androgen binding proteins. FSH levels are relatively constant in men after puberty.

In infants and children, FSH levels rise shortly after birth and then fall to very low levels (by 6 months in boys and 1-2 years in girls). At about 6-8 years, levels again rise with the beginning of puberty and the development of secondary sexual characteristics.

PREPARATION FOR TEST

No preparation is needed. A blood sample is drawn by needle from a vein in the arm.

NORMAL FINDINGS

Values may vary depending on assay method.

Adult Male

  • Luteinizing Hormone (international units/L): 1.24-7.8

  • Follicle-Stimulating Hormone (international units/L): 1.42-15.4

Adult Female

  • Follicular phase

  • Luteinizing Hormone (international units/L): 1.68-15

  • Follicle-Stimulating Hormone (international units/L): 1.37-9.9

  • Ovulatory peak

  • Luteinizing Hormone (international units/L): 21.9-56.6

  • Follicle-Stimulating Hormone (international units/L): 6.17-17.2

  • Luteal phase

  • Luteinizing Hormone (international units/L): 0.61-16.3

  • Follicle-Stimulating Hormone (international units/L): 1.09-9.2

  • Postmenopause

  • Luteinizing Hormone (international units/L): 14.2-52.3

  • Follicle-Stimulating Hormone (international units/L): 19.3-100.6

Child Male (1-10 years)

  • Luteinizing Hormone (international units/L): 0.04-3.6

  • Follicle-Stimulating Hormone (international units/L): 0.3-4.6

Child Female (1-10 years)

  • Luteinizing Hormone (international units/L): 0.03-3.9

  • Follicle-Stimulating Hormone (international units/L): 0.68-6.7

Ranges for normal findings may vary among different laboratories and hospitals. You should always check with your doctor after having lab work or other tests done to discuss the meaning of your test results and whether your values are considered within normal limits.

MEANING OF TEST

Your caregiver will go over the test results with you and discuss the importance and meaning of your results, as well as treatment options and the need for additional tests if necessary.

OBTAINING THE TEST RESULTS

It is your responsibility to obtain your test results. Ask the lab or department performing the test when and how you will get your results.