FSH (Follicle Stimulating Hormone), Serum
Fasting Required: No

Specimen: Blood

Results: 2 Business days

Description: 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 hypothalamus and the pituitary. FSH stimulates the growth and maturation of ovarian follicles (eggs) during the follicular phase of the menstrual cycle in women, which is divided into two phases, the follicular and the luteal, by a mid-cycle surge of FSH and luteinizing hormone (LH). Ovulation will occur shortly after the mid-cycle surge of hormones. During the follicular phase, FSH will initiate the production of estradiol by the follicle, and the two hormones work together in further development of the egg follicle. During the luteal phase, FSH will stimulate the production of progesterone. Both progesterone and estradiol will help the pituitary control the amount of FSH produced. FSH facilitates the ability of the ovary to respond to LH as well. At the time of menopause, the ovaries will stop functioning and FSH levels will rise. In men, FSH will stimulate the testes to produce mature sperm and will promote the production of androgen binding proteins as well. After puberty, FSH levels are relatively constant in males.

Immunoassay (IA)

Only third generation FSH testing is appropriate to assess gonadal dysfunction in non-adults (<18 years). Combined with luteinizing hormone (LH), FSH is useful in the diagnosis and management of infertility and in monitoring FSH suppressive therapy.

Clinical Significance
This test is useful in the differential diagnosis of pituitary and gonadal insufficiency and in children with precocious puberty.

Alternative Name(s)
Follicular Stimulating Hormone, Follicle Stimulating Hormone

Note: Result turn around times are an estimate and are not guaranteed. Our reference lab may need additional time due to weather, holidays, confirmation/repeat testing, or equipment maintenance.