This is a sugar-bearing protein manufactured by the anterior pituitary. Like a lot of the pituitary hormones, it surges on and off, since constant secretion would overload and deaden receptors. In women, it builds up after menses, stimulating the release of estrogen from the ovaries. Estrogen in turn stimulates the hypothalamus to increase its stimulation of LH from the pituitary, until, a day or two before ovulation, they produce a guitar-amp feedback, and the cells that produce LH start to surge follicle-stimulating hormone (FSH). The egg pops, being replaced by the corpus luteum, which produces progesterone for the next eleven to twelve days. Progesterone inhibits and lowers LH levels, as well as inhibiting levels of estrogen already being produced by the young follicles that will produce next month's egg. In men, LH is responsible for stimulation of testosterone, although FSH and the testes hormone inhibin are responsible for both the production of sperm and controlling testosterone.