Luteinizing hormone-releasing hormone (LHRH) is a hypothalamic neuropeptide which acts on the pituitary to stimulate the release of luteinizing hormone and follicle-stimulating hormone. The effects of LHRH are mediated by high-affinity G protein-coupled LHRH-receptor on pituitary gonadotropes. LHRH may act as a growth modulatory factor in tumors of the reproductive system.