New growth hormone secretagogue (GHS) analogues were synthesized and evaluated for growth hormone releasing activity. This series derived from EP-51389 is based on a gem-diamino structure. Compounds that exhibited higher in vivo GH-releasing potency than hexarelin in rat (subcutaneous administration) were then tested per os in beagle dogs and for their binding affinity to human pituitary GHS receptors and to hGHS-R 1a. Compound 7 (JMV 1843, H-Aib-(D)-Trp-(D)-gTrp-formyl) showed high potency in these tests and was selected for clinical studies.(1)