Sermorelin Acetate

Sermorelin is a synthetic 29-amino acid peptide corresponding to amino acids 1–29 of native human growth hormone-releasing hormone (GHRH), the minimal biologically active fragment required for full GHRH receptor agonism. As a direct analog of the hypothalamic neuropeptide that drives physiological GH secretion, sermorelin retains complete agonist activity at the GHRH receptor while demonstrating improved stability relative to the full 44-amino acid native peptide. Upon subcutaneous administration, sermorelin reaches peak plasma concentrations within 5–15 minutes and stimulates GH release with a half-life of approximately 11–12 minutes. Sermorelin acts through direct activation of GHRH receptors (coupled to Gs proteins) on pituitary somatotroph cells, triggering cAMP-mediated signaling that drives both GH synthesis and pulsatile secretion. Because it works upstream of the pituitary — preserving the hypothalamic-pituitary-somatotroph axis — the body's endogenous negative feedback mechanisms (somatostatin, IGF-1) remain intact, preventing supraphysiological GH levels and maintaining regulatory balance. GH released in response to sermorelin subsequently stimulates hepatic and peripheral IGF-1 production, driving downstream anabolic, lipolytic, and metabolic effects. FDA-approved for pediatric GH insufficiency (Geref®), sermorelin research in adults has documented improvements in body composition (increased lean mass, reduced visceral fat), bone mineral density, sleep quality, and quality of life metrics in age-related GH decline (somatopause). Active research areas include GH deficiency following traumatic brain injury, HIV-associated lipodystrophy, metabolic syndrome, and the comparative pharmacology of GHRH analogs versus exogenous recombinant GH administration.