MZ-4-71

**MZ-4-71** is a synthetic antagonist of *growth hormone-releasing hormone* (GH-RH), designed to suppress the secretion of GH-RH and thereby reduce levels of growth hormone (GH) and insulin-like growth factor 1 (IGF-1). In preclinical animal studies, MZ-4-71 shows robust **antitumor activity**, significantly inhibiting the growth of xenografted human renal cell carcinoma (Caki-I), osteosarcoma, and lung carcinoma. It achieves antitumor effects principally by reducing GH release from the pituitary and suppressing IGF-I/II production both systemically and within tumors. MZ-4-71 also displays *antidepressant-like*, *anxiolytic*, and *memory-improving* effects in mice, mediated in part by interaction with α1-adrenergic, 5-HT1/5-HT2 serotonergic, muscarinic acetylcholine, and GABA-A receptors. The molecule is used primarily in research and has not reached clinical development for any indication[1][2][3][4][5].