S'ermorelin, a 29 amino acid analogue of g-h, is the shortest synthetic peptide with full biological activity of GH-RH. Intravenous and subcutaneous s'ermorelin specifically stimulate g-h secretion from the anterior pituitary. Hormone responses to intravenous s'ermorelin 1μg/kg bodyweight appear to be a rapid and relatively specific test for the diagnosis of g-h deficiency. False positive g-h responses are observed in fewer children without g-h deficiency after s'ermorelin than after other provocative tests. Adult data indicate that the combination of intravenous s'ermorelin and arginine is a more specific test and this merits evaluation in children with g-h deficiency. However, normal g-h responses to intravenous s'ermorelin cannot exclude g-h deficiency due to a hypothalamic deficit: subnormal g-h response to other provocative tests is needed to confirm the presence of disease in these patients.