Lergotrile (Compound 83636), a specific inhibitor of prolactin release, was administered to 5 women with galactorrhea. Only 1 of the 5 had an elevated serum prolactin (hPRL) value, but Compound 83636 induced a decrease in serum hPRL in all cases. All patients had cessation of breast secretion within 72 days after initiation of lergotrile. LRH administration (100 µg) evoked a variable gonadotropin response before and during treatment with the ergot alkaloid. By contrast, serum prolactin values remained essentially unaltered after injection of LRH under the same conditions. (J Clin Endocrinol Metab40: 830, 1975)