The biochemistry, physiology and pharmacology of gonadotropic releasing hormone (GnRH) and GnRH analogs. GnRH agonists - patient selection, drug information, monitoring and side effects; GnRH agonist therapy for uterine leiomyomata; treatment of endometriosis with the GnRH agonists; GnRH agonists and oestrogen-progestogen replacement therapy; the oestrogen threshold hypothesis; use of GnRH agonists in programs of ovulation induction and controlled ovarian hyperstimulation; use of GnRH agonists in endoscopic and reproductive surgery; abnormal uterine bleeding - treatment with GnRG agonists; hyperandrogenism - treatment with GnRH agonists; treatment of the premenstral syndrome with GnRH agonists.