Sermorelin is a biological active analog of growth hormone releasing hormone (GHRH) that is produced by the human brain to stimulate production and release of growth hormone by the pituitary gland. During youth, ample amounts of GHRH are produced so that the pituitary is able to provide the body with sufficient growth hormone to sustain health, vitality and otherwise normal aspects of form and function. However, in some patients GHRH declines, causing reduced production and secretion of the pituitary Human Growth Hormone and thereby accelerating the sequelae of growth hormone insufficiency.

Sermorelin increases plasma growth hormone concentrations by direct stimulation of the pituitary gland.  If no Growth hormone  is secreted in response to Sermorelin therapy, whether it is due to a hypothalamic dysfunction in the presence of an intact somatotroph or not, a need for Growth hormone replacement is usually indicated.

It is for this reason that physicians are using a 3 month trial of Sermorelin Therapy for each patient. At the end of 3 months, if tests show no improvement the patient is put on Growth Hormone.

Sermorelin increases endogenous Human Growth Hormone by stimulation of the pituitary gland which does have certain advantages over direct Human Growth Hormone therapy that include:

  • Effects are regulated by negative feedback involving the inhibitory neurohormone, somatostatin, so that unlike administration of exogenous recombinant Human Growth Hormone, overdoses of endogenous Human Growth Hormone are difficult if not impossible to achieve.
  • Because of the interactive effects of sermorelin and somatostatin, release of Human Growth Hormone by the pituitary is episodic or intermittent rather than constant as with injected recombinant Human Growth Hormone.
  • Tachphylaxis is avoided because sermorelin-induced release of pituitary Human Growth Hormone is not “square wave”, but instead simulates more normal physiology.
  • Sermorelin stimulates pituitary gene transcription of Human Growth Hormone messenger RNA, increasing pituitary reserve and thereby preserving more of the growth hormone neuroendocrine axis, which is the first to fail during aging (Walker et al 1994).
  • Pituitary recrudescence resulting from sermorelin helps slow the decrease of hypophyseal hormone failure that occurs during aging thereby preserving not only youthful anatomy, but also youthful physiology (Villalbos et al 1997).

Unlike Human Growth Hormone, Sermorelin affects a more primary source of age-failure in the GH neuroendocrine axis, has more physiological activity, a better safety profile. Thus, Sermorelin should be considered a valuable alternative to Human Growth Hormone in treating patient’s with Adult Onset Growth Hormone Deficiency.