Follicle-stimulating hormone in the blood

Follicle-stimulating hormone is a peptide hormone secreted by the anterior pituitary gland. In women, follicle-stimulating hormone controls the growth of follicles until they mature and are ready for ovulation. The synergistic interaction of follicle-stimulating hormone and LH stimulates the synthesisof estradiol by granulosa cells. In men, follicle-stimulating hormone controls the growth and function of the seminiferous tubules, especially spermatogenesis.

At the beginning of the cycle, the level of follicle-stimulating hormone is higher than in the final stages of the menstrual cycle. The peak concentration of the hormone is observed in the middle of the cycle, simultaneously with the ovulatory peak of LH.

After ovulation, the level of follicle-stimulating hormone drops and again reaches the values observed in the early stages of the follicular phase by the end of the cycle.

Reference values (norm) of follicle-stimulating hormone concentration in blood serum

Age	FSH, IU/L
Children under 11 years old	0.3-6.7
Women:
Follicular phase	1.37-10
Ovulation phase	6.17-17.2
Luteal phase	1.09-9.2
Menopause period	19.3-100.6
Men	1.42-15.4

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Causes of increase and decrease of follicle-stimulating hormone

Diseases and conditions in which the concentration of follicle-stimulating hormone in the blood serum changes

Follicle stimulating hormone is elevated	Follicle stimulating hormone is decreased
Seminoma Menopause caused by ovarian dysfunction Primary gonadal hypofunction Klinefelter syndrome Shereshevsky-Turner syndrome Castration Ectopic tumors Early phase of pituitary hyperfunction Use of clomiphene, levodopa	Primary pituitary hypofunction Use of estrogens, progesterone, phenothiazine