 MK-0677 is an orally administered growth hormone secretagogue manufactured by Merck Co., Inc. that acts on the growth hormone secretagogue receptor in the anterior pituitary to stimulate the release of growth hormone. This pathway represents an additional regulation of growth hormone release from pituitary somatotrophs to that mediated by growth hormone releasing hormone stimulating and somatostatin inhibitory. Both stimulatory pathways lead to a pulsatile release of growth hormone, with approximately 4 hour intervals between peak levels. This growth hormone secretion leads to a rapid and robust up regulation of IGF-1 levels by about 50 to 100 that can be maintained with chronic therapy at a dose of 25 mgday. 