The abbreviation FSH stands for follicle stimulating hormone. This hormone belongs to the sex hormones and is responsible for the maturation of the germ cells in women and men. The FSH level in women falls and rises in the course of the female cycle. It is also important for the development of the genital organs during puberty. The FSH is supported by the Pituitary gland released, a small hormonal gland in the brain also called the pituitary gland.


As a sex hormone, FSH, in combination with other hormones, leads to the maturation of the germ cells in men and women. In women, FSH acts on cells that have Egg cell surround, estrogen produce and promote the maturation of the egg cell. The egg cell with these cells is called follicle designated.However, to ensure that only one follicle matures in women each month and that the lining of the uterus can also prepare for a possible pregnancy, precise coordination of FSH and the other sex hormones is important.

The concentrations of the various hormones are different in the course of a cycle and influence each other. FSH promotes estrogen synthesis, but at the same time the FSH release is caused by high estrogen levels inhibited. The FSH level initially rises immediately after menstruation and ensures that a follicle matures. Shortly before the ovulation, after about 14 days, the FSH initially falls and briefly increases sharply at the time of ovulation. In men, the FSH concentration is more constant. Here the destination of the FSH are certain cells in the Testicles (Sertoli cells or nurse cells), which, under its influence, control sperm maturation with the help of testosterone. At the beginning of puberty, too, the FSH level rises, along with other sex hormones, which leads to the development of the genital organs.

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What does the value say?

In the course of life and monthly cycle the FSH values ​​change. After Menstruation and after ovulation the values ​​are between 2-10 U / l. The values ​​are higher near ovulation. Here are values ​​up to 30 U / l still normal. -after the Menopause the FSH level rises even more. Values ​​over 20 U / l are the norm. You can also over 100 U / l climb.

In contrast to this, in the pregnancy very low values ​​below 1.5 U / l. In men, the FSH values ​​are between 2-10 U / l. In women and men, FSH is released intermittently and irregularly, so that a certain margin in the values ​​has no disease value. The normal values ​​for children are different in the various age groups.

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What can trigger elevated values?

Elevated levels are normal during menopause. Because the FSH release is inhibited by high estrogen levels. The Estrogen production however, it decreases steadily during the menopause, as the function of the ovaries slowly ceases and so no more estrogen can be produced. This leads to menstrual cycles without ovulation and high FSH levels.

Even with other causes for one Underactive ovaries the FSH levels are increased, e.g. after removing an ovary. Because even in these cases there is no feedback or inhibition of the FSH release by estrogen. Elevated FSH levels shortly before ovulation are completely normal. A high FSH concentration is necessary here for the development of the egg cell and thus for fertility. Men can also have elevated FSH levels. Here, too, is the cause of one thing Underactive gonadswhich can be hereditary, for example.

What can trigger lowered values?

A harmless cause of low FSH levels is stress. Also at anorexia There is no menstrual period because, among other things, the FSH values ​​are too low. This also makes sense because in this situation the body does not have enough resources to sustain a pregnancy. This can also be a rarer cause polycystic ovarian syndrome which is a metabolic disease with many cysts in the ovaries.

Another cause can be underactive in both women and men Anterior pituitary gland (Anterior pituitary insufficiency) lie. Not enough FSH is produced here and the FSH concentration in the body drops. Reasons for anterior pituitary insufficiency can be Tumors, trauma, hemorrhage or Inflammation be. Autoimmune processes, i.e. processes in which the body turns against itself, are also possible as a cause. But even with disorders in the hypothalamus, reduced FSH concentrations can occur, because there the Gonatropin-releasing hormone which stimulates FSH release.

Test for the FSH value

An FSH test is among other things at unfulfilled desire to have children or lack of puberty examined. The FSH concentration in the serum is determined. For this purpose, the doctor Blood drawn. Since the test is a snapshot, it is important to note the day of the cycle on which the blood is drawn. To obtain a meaningful value, the FSH test should be between the 3rd and 5th day of the cycle will be removed, i.e. during the menstrual period. Furthermore, it must be noted that hormone preparations such as the pillthat falsify values. Therefore, they should not be taken at least 4-6 weeks before the blood sample is taken.