A hormone released by the anterior lobe of the pituitary gland. It is one of the gonadotrophins, the other being follicle stimulating hormone (FSH)
In both males and females, LH stimulates the production of sex steroids from the gonads. Leydig cells in male testes respond to LH by producing testosterone, while theca cells in the female ovary respond to LH by producing estrogen.
In females, a LH surge about halfway through the menstrual cycle triggers the onset of ovulation. LH also induces the ovulated follicle to become a corpus luteum, which then secretes progesterone.