The Gonadotropin Releasing Hormone, secreted by the hypothalamus; GnRH stimulates the release of LH and FSH from the pituitary gland.

A form of treatment which uses a portable, battery-driven pump to replace the missing GnRH by releasing it in pulses at regular intervals, typically every 90 minutes.

A hormone which regulates the function of the gonads; the two main gonadotrophins are LH and FSH, both released from the pituitary gland.

A substance made by the body that functions to regulate cell division and cell survival. Some growth factors are also produced in the laboratory and used in biological therapy.

Growth Hormone Research Society.

A usually harmless female-like enlargement of one or both breasts in males; occurs commonly in teen-aged boys, but may be a characteristic of some hypogonadal males.