Wikipedia
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). Unlike many related drugs, ulimorelin is peripherally selective and has little or no effect on growth hormone (GH) release, instead having a specific laxative effect. 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. Human trial results have been promising, however a common side effect of reduced blood pressure led to the discovery that ulimorelin also acts as an antagonist of α-adrenoceptors in addition to its intended mechanism of ghrelin receptor agonism.