The motilin receptor (MTLR) represents a clinically useful pharmacological target, as agonists binding to the MTLR have gastroprokinetic properties. Motilin is a 22 amino acid peptide that potently stimulates gastrointestinal contractility. The biological effects of motilin are mediated by a Gq-coupled seven transmembrane protein, currently termed motilin receptor (MR) that shares significant sequence similarity with the ghrelin receptor. The motilin receptor is also activated by the antibiotic erythromycin; this interaction appears to mediate some of the gastrointestinal side effects of erythromycin. Although motilides (non-antibiotic derivatives of erythromycin) such as ABT-229 have been investigated for trea™ent of diabetic gastroporesis, the effectiveness has been limited by tachyphylaxis (decreased response to ligand) resulting from receptor downregulation. Agonists of the motilin receptor with reduced densensitization activity remain a potential trea™ent for disorders of gastric motility.