Description

Product Specifications

Field	Details
Product Name	Sermoreln (GRF 1–29 NH₂)
CAS Number	86168-78-7 (free base) / 114466-38-5 (acetate salt)
Molecular Formula	C₁₄₉H₂₄₆N₄₄O₄₂S
Molecular Weight	≈ 3357.9 Da
Amino Acid Sequence	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
Length	29 amino acids (N-terminal fragment of native 44-aa GHRH)
Form	Lyophilized powder (not reconstituted)
Purity	≥98% (HPLC verified)
Third-Party Testing	Janoshik Analytical — Certificate of Analysis available
Storage	−20°C (unreconstituted). Protect from light and moisture.
Vial	3 mL sealed vial with flip-top cap
Content	5 mg per vial

Molecular Profile

Sermoreln is a truncated synthetic analog consisting of the first 29 residues of the endogenous 44-amino acid GHRH sequence. This fragment was identified in early structural characterization studies as the shortest peptide retaining full receptor-level binding activity at the GHRH receptor (GHRHR). The molecule carries a C-terminal amide modification and has a molecular weight of approximately 3357.9 Da with the formula C₁₄₉H₂₄₆N₄₄O₄₂S.

Receptor Interaction and Signaling Pathways

In preclinical models and in vitro systems, Sermoreln was observed to bind selectively to pituitary GHRH receptors (GHRHR), a G-protein coupled receptor expressed on somatotroph cells. Receptor engagement was reported to activate adenylate cyclase, increasing intracellular cyclic adenosine monophosphate (cAMP) concentrations. Downstream, cAMP-dependent protein kinase A (PKA) activation was studied for its role in phosphorylation cascades associated with somatotropic signaling. Research also examined calcium-mediated second messenger pathways as parallel signaling mechanisms following GHRHR activation.

Structural and Analytical Characterization

Sermoreln identity and purity are characterized through high-performance liquid chromatography (HPLC) and mass spectrometry (MS). The peptide contains D-amino acid–free, all-L configuration residues. Due to the presence of methionine at position 27, the compound is susceptible to oxidative degradation, necessitating storage under inert atmosphere at −20°C in lyophilized form. Reconstituted solutions should be refrigerated at 2–8°C and used promptly, with repeated freeze–thaw cycles avoided.

Laboratory Research Applications

Sermoreln has been utilized in laboratory research to investigate GHRH receptor pharmacology, intracellular cAMP signaling fidelity, and hypothalamic–pituitary axis dynamics. In cell culture models, studies examined receptor binding kinetics, downstream phosphorylation events, and gene transcription associated with somatotropic pathways. In animal research models, investigators explored pulsatile signaling dynamics, feedback regulation through somatostatin, and GH/IGF-1 axis interactions. The peptide’s relatively short estimated half-life (approximately 10–20 minutes in plasma) made it a useful tool for studying transient receptor activation patterns.

Quality and Supply

Each lot of Sermoreln from Peptide Minds undergoes third-party analytical testing by Janoshik Analytical to verify identity, purity (≥98% by HPLC), and absence of microbial contamination. Certificates of Analysis are available upon request.

⚠️ RESEARCH USE ONLY This product is sold exclusively for laboratory research, in-vitro testing, and analytical applications. NOT for human consumption, veterinary use, clinical application, or any in-vivo use. Peptide Minds is a chemical research compound supplier. We are NOT a pharmacy, compounding facility, or medical provider.

⚠️ REGULATORY STATUS A compound with the same peptide sequence was previously FDA-approved (1997–2008) under the brand name Geref® for diagnostic purposes. It was withdrawn from the U.S. market in 2008 for commercial reasons (not safety-related). This product is a research compound. It is not the discontinued pharmaceutical product and is not FDA-approved for any therapeutic or diagnostic use.

✅ QUALITY ASSURANCE Third-party tested by Janoshik Analytical. Certificate of Analysis (COA) available for each lot. ≥98% purity verified by HPLC. Manufactured under controlled conditions with full traceability.

Research Background

Discovery and Historical Context

The identification of growth hormone–releasing hormone (GHRH) represented a major milestone in neuroendocrinology. In the early 1980s, two independent research groups isolated and characterized GHRH from pancreatic islet tumors associated with ectopic GHRH secretion. The endogenous molecule consisted of 44 amino acids, but subsequent structure–activity relationship studies demonstrated that the first 29 residues constituted the minimal fragment necessary for full receptor binding and activation. This truncated analog, designated GRF 1–29 NH₂ (later named Sermoreln), became a foundational tool in GHRH receptor research.

The compound received regulatory approval in 1997 under the brand name Geref®, where it was authorized for use as a diagnostic agent to evaluate pituitary GH secretory capacity. The branded product was voluntarily withdrawn from the U.S. market in 2008 by its manufacturer for commercial reasons unrelated to safety concerns. Since its withdrawal from regulated pharmaceutical channels, the compound has remained available exclusively through research chemical suppliers and, in certain jurisdictions, compounding pharmacies.

Structural Characteristics

Sermoreln is a linear 29-residue peptide with the sequence 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. The C-terminal amidation contributes to receptor binding affinity and confers partial resistance to carboxypeptidase-mediated degradation. The molecule contains no non-natural amino acids or D-stereoisomers, distinguishing it structurally from other growth hormone secretagogue peptides such as GHRP-2 and GHRP-6, which incorporate D-amino acid substitutions.

The methionine residue at position 27 represents a site of potential oxidative modification, which can yield methionine sulfoxide derivatives and reduce receptor binding affinity. This structural vulnerability informed standard handling protocols requiring inert-atmosphere packaging and cold storage at −20°C for lyophilized material.

In structural comparison with the full-length 44-amino acid GHRH molecule, Sermoreln lacks the C-terminal 15 residues (positions 30–44). Early truncation studies demonstrated that these residues were not essential for receptor binding, as the N-terminal domain mediates the primary interaction with the extracellular binding pocket of the GHRHR. The 29-residue fragment was confirmed as the shortest sequence retaining measurable bioactivity in receptor binding assays.

GHRH Receptor Systems Studied in Research

The growth hormone–releasing hormone receptor (GHRHR) belongs to the Class B (secretin-like) subfamily of G-protein coupled receptors. It is predominantly expressed on anterior pituitary somatotroph cells, where it couples to the stimulatory G-protein (Gₐ) to activate adenylate cyclase. Early receptor characterization studies examined Sermoreln as a reference agonist for mapping GHRHR binding kinetics, activation thresholds, and desensitization patterns.

Research examined how GHRHR activation by Sermoreln initiated cAMP accumulation, which in turn activated protein kinase A (PKA). PKA-mediated phosphorylation of transcription factors, including CREB (cAMP response element-binding protein), was investigated as a downstream regulatory step in GH gene expression. Parallel studies examined calcium influx through voltage-gated calcium channels as a co-regulatory mechanism contributing to vesicular GH exocytosis following GHRHR stimulation.

Investigators also explored the interplay between GHRHR and somatostatin receptor (SSTR) signaling. Somatostatin, acting through SSTR subtypes (primarily SSTR2 and SSTR5), was reported to inhibit cAMP production and counteract GHRHR-mediated signaling. This antagonistic relationship formed the basis for studying pulsatile GH secretion dynamics, where alternating GHRH and somatostatin tone governed oscillatory patterns of somatotroph activation.

Additionally, the interaction between GHRHR and growth hormone secretagogue receptor (GHS-R1a, the ghrelin receptor) signaling was a subject of investigation. Studies in ovine somatotroph models examined how co-activation of GHRHR and GHS-R1a produced signaling responses exceeding the additive effects of either pathway alone. Mechanistically, GHRP compounds were reported to suppress somatostatin receptor (sst-1 and sst-2) mRNA expression, potentially attenuating inhibitory feedback and allowing GHRH-mediated signaling to proceed with reduced opposition.

Laboratory Methodologies

In vitro studies utilized primary pituitary cell cultures and immortalized somatotroph cell lines to examine Sermoreln’s effects on intracellular cAMP concentrations, calcium mobilization, and GH mRNA transcription. Radioimmunoassay (RIA) and enzyme-linked immunosorbent assay (ELISA) techniques were employed to quantify GH release in conditioned media following peptide exposure at varying concentrations and time points.

In animal research models, investigators administered Sermoreln via intravenous or subcutaneous routes to study GH secretory dynamics over defined observation windows. Blood sampling at timed intervals allowed construction of GH pulsatility profiles and area-under-curve (AUC) calculations. Comparative studies examined Sermoreln alone versus co-administration with GHS-R1a agonists to characterize potential synergistic signaling interactions.

Analytical characterization of Sermoreln preparations was performed using reversed-phase HPLC for purity assessment, liquid chromatography–mass spectrometry (LC-MS) for molecular weight confirmation, and amino acid analysis for sequence verification. These methods established quality control benchmarks for research-grade peptide standards.

Analytical Characterization

Standard analytical methods for sermoreln characterization include reversed-phase high-performance liquid chromatography (RP-HPLC), which separates the target peptide from synthesis-related impurities and degradation products. Electrospray ionization mass spectrometry (ESI-MS) confirms the molecular ion at the expected m/z ratio consistent with the theoretical molecular weight of 3357.9 Da. Amino acid composition analysis following acid hydrolysis provides independent verification of the peptide’s residue content, confirming the presence of the expected amino acid ratios.

Stability studies examined degradation kinetics under various storage conditions, establishing that lyophilized material maintained integrity for extended periods at −20°C, while reconstituted solutions exhibited measurable degradation within days at ambient temperature. Methionine oxidation at position 27 was identified as the primary degradation pathway, monitored by shifts in HPLC retention time and corresponding mass spectral changes.

References

1. Montero-Hidalgo, A. J., Del Rio-Moreno, M., Pérez-Gómez, J. M., Luque, R. M., & Kineman, R. D. (2025). Update on regulation of GHRH and its actions on GH secretion in health and disease. Reviews in Endocrine & Metabolic Disorders, 26(3), 305–320.
2. Ben-Shlomo, A., & Melmed, S. (2010). Pituitary somatostatin receptor signaling. Trends in Endocrinology and Metabolism, 21(3), 123–133.
3. Olarescu, N. C., Gunawardane, K., Hanson, T. K., et al. (2025). Normal Physiology of Growth Hormone in Normal Adults. Endotext. South Dartmouth (MA): MDText.com, Inc.
4. Gelander, L., et al. Short-term effects of Sermoreln and GHRH 1–40 on GH, IGF-1, prolactin, FSH, and LH levels. Referenced in PMC7108996.
5. Corpas, E., et al. Sermoreln effects on GH and IGF-1 levels in young and elderly men. Referenced in PMC7108996.

 Compliance Statement

LEGAL DISCLAIMER — RESEARCH USE ONLY FOR RESEARCH USE ONLY. NOT FOR HUMAN CONSUMPTION OR VETERINARY USE. This product is sold exclusively for laboratory research applications, in-vitro testing, and analytical purposes. It is not approved by the FDA for human use, clinical applications, therapeutic purposes, or diagnostic use. Not intended to diagnose, treat, cure, or prevent any disease or medical condition. Peptide Minds (operated by Accelairate LLC) is a research chemical compound supplier. We are not a pharmacy, compounding facility, or medical provider. Products are manufactured and sold under Research Use Only (RUO) classification. This product is not the discontinued pharmaceutical product Geref®. The compound name Sermoreln is a proprietary product identifier used by Peptide Minds and should not be equated with any FDA-approved drug product. By purchasing this product, the buyer acknowledges that it will be used solely for qualified laboratory research purposes and agrees to comply with all applicable federal, state, and local regulations governing the purchase and use of research compounds. All research references cited are from peer-reviewed published literature provided for informational context only. Inclusion of research citations does not constitute claims of product efficacy for any application.