The invention relates generally to the use of pharmaceutical compositions to increase milk production alone or in combination with certain biological active ingredients. Specifically, the method relates to the use of pharmaceutical compositions that will act on the feedback of the intrinsic regulatory pathway in the mammalian mammary gland. The present invention provides for as a method of increasing bovine milk production as well as a method of correcting certain human lactation abnormalities. Preferably, the compounds used in the methods of the present invention are one or more active agents capable of inhibiting peripheral aromatic amino acid decarboxylase (AADC) enzymes, peripheral tryptophan hydroxylase (TPH) enzymes, peripheral serotonin (5-HT) enzymes, or a combination of enzymes thereof.