Sermorelin Acetate

Sermorelin Acetate (INN; brand names Geref, Gerel), also known as GHRH (1-29), is the acetate salt of an amidated synthetic 29-amino acid peptide (GRF 1-29 NH₂) that corresponds to the amino-terminal segment of the naturally occurring human growth hormone-releasing hormone (GHRH or GRF) consisting of 44 amino acid residues. As the shortest fully functional fragment of endogenous GHRH, sermorelin retains complete biological activity. The compound was first approved by the FDA in 1990 as Geref and has been used for the diagnosis and treatment of growth hormone deficiency, particularly in children with idiopathic growth hormone deficiency.

Sermorelin exerts its effects by binding to the growth hormone-releasing hormone receptor (GHRH-R), a G protein-coupled receptor (GPCR) predominantly expressed on somatotroph cells in the anterior pituitary gland. As a GHRH analog, sermorelin competitively binds to the GHRH-R, inducing a conformational change that activates the associated heterotrimeric G protein (primarily the stimulatory G protein, Gs). This activation triggers intracellular signaling cascades that stimulate the synthesis and pulsatile release of endogenous growth hormone (GH), which in turn elevates circulating levels of insulin-like growth factor 1 (IGF-1). With an unmodified half-life of approximately 11–12 minutes, sermorelin produces a tightly controlled, pulsatile GH release that faithfully mimics natural endocrine rhythms, contrasting sharply with continuous-release analogs.

• Growth Hormone Deficiency Diagnosis: Employed as a diagnostic agent to assess pituitary GH reserve and evaluate growth hormone secretion, with hormone responses to intravenous sermorelin serving as a rapid and relatively specific test for the diagnosis of growth hormone deficiency.
• Pediatric Endocrinology: Investigated for the treatment of children with idiopathic growth hormone deficiency, particularly in cases where the deficit lies in hypothalamic GHRH synthesis or release rather than in GH itself.
• Pituitary Function Studies: Utilized as a validated diagnostic probe for pituitary function, achieving approximately 50% IGF-1 elevation in combination protocols with GHRP-2 or GHRP-6.
• Endocrinology and GH-Axis Research: Employed as a research tool to study GHRH receptor signaling, GH secretion dynamics, and the physiological regulation of the hypothalamic-pituitary-somatotropic axis.
• Cell Proliferation Studies: Investigated for its effects on cell proliferation, with studies demonstrating increased proliferation of certain cell lines and enhanced vascular endothelial growth factor (VEGF) secretion.

CAS Number: 86168-78-7 (free base); 114466-38-5 (acetate salt)
Molecular Formula: C₁₄₉H₂₄₆N₄₄O₄₂S
Molecular Weight: 3,357.93 g/mol (free base)
Sequence: H-Tyr-Ala-Asp-Ala-Ile-Phe-Thr-Asn-Ser-Tyr-Arg-Lys-Val-Leu-Gly-Gln-Leu-Ser-Ala-Arg-Lys-Leu-Leu-Gln-Asp-Ile-Met-Ser-Arg-NH₂
Purity: ≥ 99%
Form: Lyophilized powder
Storage: Store at ≤ -20°C in a cool, dry place, protected from light and moisture
Solubility: Soluble in sterile water and DMSO; prepare working solutions per laboratory protocol