Semorelin Acetate is the acetate salt of a synthetic 29-amino acid peptide corresponding to the first 29 amino acids of human growth hormone-releasing hormone (GHRH 1-29). The amino acid sequence is 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, with a molecular weight of approximately 3,357.9 Da. Semorelin retains full biological activity at the GHRH receptor (GHRHR), as the N-terminal 29 residues contain the complete receptor-binding and activation domain of the 44-amino acid native GHRH molecule.
In pituitary somatotroph cell cultures, Semorelin binds to GHRHR, a class B G-protein coupled receptor, activating the Gs/adenylyl cyclase/cAMP/PKA signaling cascade. This leads to CREB phosphorylation and subsequent transcriptional activation of the GH-1 gene. Electrophysiological studies in pituitary cell preparations have demonstrated that Semorelin-induced cAMP elevation opens voltage-gated calcium channels, triggering GH vesicle exocytosis. Concentration-response studies indicate that Semorelin achieves maximal somatotroph stimulation with efficacy equivalent to full-length GHRH(1-44) in these model systems.
Somatotroph axis research applications include investigation of GHRHR desensitization kinetics following sustained versus pulsatile compound exposure. In cell culture time-course experiments, Semorelin has been used to study receptor internalization, β-arrestin recruitment, and receptor recycling dynamics. Comparative studies with modified GHRH analogs (such as CJC-1295) enable investigation of structure-activity relationships governing GHRHR activation and the effects of enzymatic stability modifications.
Additional research applications include IGF-1 axis downstream signaling in hepatocyte models, where GH-stimulated JAK2/STAT5 activation has been studied. In osteoblast cell cultures, Semorelin-stimulated GH release models have been used to examine effects on bone formation markers. Aging research utilizing senescent pituitary cell models has investigated age-related changes in GHRHR density and signaling efficiency.
Erosyn Labs provides Semorelin Acetate as a lyophilized powder at ≥98% purity by HPLC with mass spectrometry identity confirmation. A comprehensive Certificate of Analysis accompanies each lot. Reconstitution in bacteriostatic water is recommended. Store lyophilized material at -20°C. Reconstituted solutions should be maintained at 2–8°C and utilized within 21 days. Standard aseptic peptide handling protocols are recommended.
For research and laboratory use only. Not for human consumption.
