About leuprolidegnrh analog, lh-rh agonist, antineoplastic.mechanism of action of leuprolidethis gnrh analogue is a potent inhibitor of gonadotropin secretion. by continuous administration of this drug cause down regulation of lhrh receptors and an uncoupling of lhrh signal transduction mechanism. this results a desensitization of gonadotropins and marked reduction in the secretion of bioactive lh &fsh. this reduction in circulating lh&fsh together with down regulation of gnrh receptors produces a complete inhibition of testicular and ovarian function and a fall in sex steroid level. this drug also have direct inhibitory effect on lhrh receptors present in extra pituitary tissues like tumors .reducing level of estrogen in women reduce the size of the endometrial implants and decrease dysmenorrhea and pelvic pain associated with endometriasis.