I. GnRH analogues are never effective in treating secondary hypogonadism. II. Amenorrhea can be due to hypogonadism.
Extra info: Secondary hypogonadism is caused by insufficient secretion of gonadotropic hormones. By administering GnRH analogues, the release of gonadotropic hormones from the pituitary can be stimulated. Decreased LH/FSH levels can result in the absence of follicle maturation and, consequently, also in decreased estrogen and progestagen levels. All these events result in amenorrhea.