ulimorelin ulimorelin ulimorelin (inn, usan) (developmental code name tzp-101) is a drug with a modified cyclic peptide structure which acts as a selective agonist of the ghrelin/growth hormone secretagogue receptor (ghsr-1a).. unlike many related drugs, ulimorelin has little or no effect on growth hormone (gh) release in rats. however, like ghrelin and other ghrelin agonists, ulimorelin does stimulate gh release with concomitant increases in insulin-like growth factor 1 (igf-1) in humans. it has been researched for enhancing gastrointestinal motility, especially in gastroparesis and in aiding recovery of bowel function following gastrointestinal surgery, where opioid analgesic drugs used for post-operative pain relief may worsen existing constipation. while ulimorelin has been shown to increase both upper and lower gastrointestinal motility in rats, and showed promising results initially in humans, it failed in pivotal clinical trials in post operative ileus. ulimorelinclinical dataatc codenoneidentifiers iupac name (7r,10r,13s,16r)-13-cyclopropyl-7-(4-fluorobenzyl)-10,11,16-trimethyl-17-oxa-5,8,11,14-tetrazabicyclodocosa-1(22),18,20-triene-6,9,12-trione cas number842131-33-3pubchem cid11526696chemspider9701482uniilgi67mcw2skeggd09981comptox dashboard (epa)dtxsid00233139 chemical and physical dataformulac30h39fn4o4molar mass538.664 g·mol−13d model (jsmol)interactive image smiles c1cn(c(=o)n((c(=o)n(c(=o)ncccc2=cc=cc=c2o1)cc3=cc=c(c=c3)f)c)c)c4cc4 inchi inchi=1s/c30h39fn4o4/c1-19-18-33-27(23-12-13-23)30(38)35(3)20(2)28(36)34-25(17-21-10-14-24(31)15-11-21)29(37)32-16-6-8-22-7-4-5-9-26(22)39-19/h4-5,7,9-11,14-15,19-20,23,25,27,33h,6,8,12-13,16-18h2,1-3h3,(h,32,37)(h,34,36)/t19-,20-,25-,27+/m1/s1key:wgypajvjmxqxtr-abnzckjzsa-n a common side effect of ghrelin is reduced blood pressure. ulimorelin has been shown to inhibit vasoconstriction of rat arteries in vitro elicited by the α1-adrenoceptors agonists phenylephrine and methoxamine, and to increase artery tension at high concentrations. effects on blood pressure, however, were not observed in human clinical trials.