Thyrotropin-releasing hormone (TRH), also called thyrotropin-releasing factor (TRF), thyroliberin or protirelin, is a tropic, tripeptidal hormone that stimulates the release of TSH (thyroid-stimulating hormone) and prolactin from the anterior pituitary. TRH has been used clinically for the treatment of spinocerebellar degeneration and disturbance of consciousness in humans. TRH is produced by the hypothalamus in medial neurons of the paraventricular nucleus. At the beginning, it is synthesized as a 242aa precursor polypeptide that contains 6 copies of the sequence -Glu-His-Pro-Gly-, flanked by di-basic peptides that are later processed through proteolysis to give the mature TRH molecule. TRH travels across the median eminence to the anterior pituitary gland via the hypophyseal portal system where it stimulates the release of thyroid-stimulating hormone from cells called thyrotropes and excess levels inhibit dopamine which will then stimulate the release of prolactin which in turn decreases GnRH. TRH can also be detected in other areas of the body including the gastrointestinal system and pancreatic islets, as well as in the brain.