Page last updated April 2020

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FSH (Follicle Stimulating Hormone) is a hormone, released from the anterior pituitary gland. It is a gonadotropin, stimulating the ovary to produce hormones and ovulate. 

FSH causes an ovarian follicle to develop and drives the pre-ovulatory rise in estrogen.

There is spike of FSH coincidental with the LH surge. These lead to ovulation within a few hours.

Elevations found in:

  • Ovulation
  • Ovarian failure
  • Testicular Feminization Syndrome

Decreases found in:

  • Polycystic Ovary Syndrome (PCO, Stein-Levinthal Syndrome)
  • Amenorrhea-Galactorrhea Syndrome
  • Pituitary failure

Normal Values*

Men 4-25 mIU/ml 4-25 IU/L


4-30 mIU/ml 4-30 IU/L
2 x baseline  
40-250 mIU/ml 40-250 IU/L

*These are general values taken from a variety of sources. The actual normal values may vary from lab to lab and from one type of testing protocol to another.

FSH levels in one cycle