There are several types of drugs used during IVF treatment cycles.  These are Gonadotrophin-releasing hormone (GnRH) analogues ( Buserelin) are used to block the release of your hormones; Gonadotropins (Fostimon) to stimulate egg production; (GnRH) antagonists (Cetrotide) which block ovulation and progesterone (cyclogest) to help the endometrium and maintain pregnancy.