The melanocyte-stimulating hormone (MSH)-release inhibiting hormone, prolyl-leucyl-glycinamide (MRIH-I), is a hypothalamic hormone active in animal systems used as models of depression.
In a double-blind, clinical trial, four of five patients with mental depression, who received 60 mg of MRIH-I for each of six consecutive days, experienced marked improvement for their symptoms within. two to three days.
The preliminary nature of these findings, however, is emphasized by the improvement in two of four patients receiving a placebo and only two of five patients receiving 150 mg of MRIH-I.
Ehrensing RH, Kastin AJ. Melanocyte-Stimulating Hormone-Release Inhibiting Hormone as an AntidepressantA Pilot Study. Arch Gen Psychiatry. 1974;30(1):63-65. doi:10.1001/archpsyc.1974.01760070047007