Luteinizing-hormone-releasing hormone (LHRH) (GnRH) is a decapeptide (pyroQHWSYKLRPG-NH2) trophic hormone that regulates the release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) from the anterior pituitary. Various analogues have been developed using D-amino acids to increase resistance to degradation. These analogues are used as potential targeting agents in the development of chemotherapies and as possible agonists and antagonist of the LHRH receptor.