What is Luteinising Hormone?
Luteinising hormone is a glycoprotein gonadotrophin secreted by the anterior pituitary under pulsatile GnRH control. In women the mid-cycle LH surge triggers ovulation and supports the corpus luteum; in men LH stimulates testicular Leydig cells to produce testosterone. Because secretion is markedly pulsatile and the half-life short, single LH values fluctuate, and the LH-to-FSH ratio carries additional diagnostic information in some conditions.