PIH

PIH or prolactostatin inhibits the release of prolactin from the anterior pituitary lobe. If this inhibition disappears, women can develop milk flow from the mammary glands even without pregnancy. PIH is exceptionally not a peptide, but the amino acid derivative dopamine. Patients who are treated with dopamine inhibitors as part of a psychiatric illness therefore suffer an excessive release of prolactin. So they have milk flow in the mammary gland, similar to breastfeeding mothers.