GnRH antagonists work against the LH and FSH hormones in the body. These drugs are used during IVF treatments to prevent the loss of eggs which have ovulated before they can be retrieved.
They are also used during IUI treatments if fertilization must be delayed and are used to reduce the risk of ovarian hyperstimulation syndrome which happens if estrogen is too high.
Lupron, Synarel, Zoladex
Known as GnRH agonists, they cause a surge of LH and FSH and then cause production to cease, preventing ovulation and limiting estrogen. Used in IVF, these drugs allow the doctors to control ovulation.
Pergonal, Humegon, Repronex, Menopur
Human menopausal gonadotropins (hMG), these fertility drugs are a combination of LH and FSH. They are not used frequently, often just in special cases. These too are injectables.
Remember, these are drugs and as with all drugs, there are risks and side effects. High order multiple pregnancy and ovarian hyperstimulation syndrome are potential effects of the use of these drugs.