About 20% of all menstrual cycle disorders are due to a hyperprolactinemia. Although changes in the bony area of the sella indicating intrasellar space-requiring processes have been found in only 30% of these women presenting hyperprolactinemic ovarian insufficiency, an adenoma of the pituitary gland is probably also responsible for the hyperprolactinemia observed in the rest of the cases. Treatment is however not strictly necessary, as long as there are no other endocrine dysfunctions, and a pregnancy is not desired. Side-effects of a therapy of dopamine agonists can be diminished by a gradually increasing dosage.