Follicle-stimulating hormone (FSH)

Follicle-stimulating hormone (FSH) is a gonadotropin, a hormone that acts on the gonads (the ovaries or testes). This hormone performs essential functions related to reproduction and pubertal development. FSH stimulates growth of the ovarian follicles and stimulates sperm production.

What is follicle-stimulating hormone?

Follicle-stimulating hormone (FSH) is a hormone involved in reproduction and the development of eggs and sperm. FSH is produced by the pituitary gland, a small pea-sized gland situated at the base of the brain. To produce FSH, the pituitary gland must receive messages from the hypothalamus part of the brain. FSH then stimulates the ovaries or the testes to produce and mature eggs or sperm.

When evaluating fertility issues, doctors may test blood for FSH levels. Certain conditions that affect the hypothalamus, pituitary gland, or reproductive organs can cause the production of too little or too much FSH, which may result in infertility. High FSH can also indicate menopause or testicular damage or failure.

FSH and male fertility

FSH stimulates the testicles to produce sperm and also facilitates the production of androgen-binding proteins necessary for sperm production. FSH levels between 1.5 and 12.4 mIU/mL in male adults is considered normal. FSH levels can be checked with a blood test.

High FSH levels in people with testes may mean that the testicles are not functioning correctly due to advanced age, testicular trauma, genetic problems, hormone treatment, or certain tumors. Low FSH levels in men may indicate that the pituitary gland is not producing hormones properly, perhaps due to injury or tumor.

FSH as a fertility medication

If there are issues with ovulation or sperm production, FSH may be used as a fertility medication. FSH can be given as an injection to stimulate the ovaries to produce follicles that contain eggs. It is used in fertility treatments like IVF to help the body produce as many viable eggs as possible.

FSH therapy is also used to stimulate sperm production. It is often combined with luteinizing hormone (LH) and human chorionic gonadotropin (hCG).
Common brand names for FSH injections include Follistim and Gonal-F.

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