The influence of the prolactin inhibitor bromocriptin (CB 154) on human luteal function in vivo.

Five volunteers with normal ovarian cycles received oral doses of 2×2.5 mg or 3×2.5 mg bromocriptin (CB 154)/day respectively. The treatment started at the onset of menstruation and lasted one complete cycle. In addition to the decrease of prolactin secretion, a reduction of plasma progesterone concentrations during the corpus luteum phase was demonstrated. This fall of progesterone seemed to be preferentially due to bromocriptin-induced hypoprolactinaemia and not to direct ovarian effects of the drug.