Overview
Growth hormone secretagogues are synthetic peptides studied as agonists at two distinct pituitary receptor systems: the growth hormone–releasing hormone receptor (GHRHR) and the growth hormone secretagogue receptor (GHS-R1a), also known as the ghrelin receptor. Solira supplies six compounds in this category, characterized here by receptor class, molecular weight, and structural modification rather than by application. All are supplied for in-vitro laboratory research only and are not approved for human use.
Receptor Biology
The two receptor systems in this category are structurally and mechanistically distinct, which is why compounds targeting them are frequently co-studied. GHRHR is a class B G-protein-coupled receptor expressed on pituitary somatotrope cells; agonist binding signals through Gs / cAMP / PKA cascades. GHS-R1a is a class A G-protein-coupled receptor with constitutive activity, signalling primarily through Gq / PLC / IP3 with downstream intracellular calcium mobilisation. Because the two receptors converge on the same somatotrope population through separate second-messenger pathways, combinatorial preparations pairing a GHRHR agonist with a GHS-R1a agonist are a common research tool for studying receptor cross-talk and pathway additivity in cultured pituitary preparations.
Structural Modifications
Two structural features distinguish the compounds in this category and are the basis for most comparative research work.
- Tetrasubstitution — substitution at four positions of the native GRF (1-29) sequence increases resistance to enzymatic degradation by dipeptidyl peptidase-4 relative to the unmodified fragment. The tetrasubstituted 29-residue fragment is designated Mod GRF (1-29).
- Drug affinity complex (DAC) — a maleimidoproprionic acid group that forms a covalent bond with serum albumin, substantially extending circulating persistence relative to the same sequence without the modification. Compounds are supplied in both DAC and non-DAC forms so the modification itself can be studied as a variable.
Solira’s Catalog
Six compounds, grouped by receptor class:
- CJC-1295 NO DAC (Mod GRF 1-29) — GHRHR agonist. Tetrasubstituted GRF (1-29) fragment without the albumin-binding modification. 3367.93 g/mol.
- CJC-1295 with DAC — GHRHR agonist. Same core sequence carrying the drug affinity complex. 3647.24 g/mol.
- Sermorelin Acetate — GHRHR agonist. Unmodified GRF (1-29) fragment, the reference sequence against which the tetrasubstituted analogs are compared. 3357.88 g/mol.
- Tesamorelin — GHRHR agonist. Full-length 44-residue GRF analog carrying a trans-3-hexenoyl modification at the N-terminus. 5135.92 g/mol.
- Ipamorelin — GHS-R1a agonist. Pentapeptide, the smallest compound in this category and selective for the ghrelin receptor. 711.85 g/mol.
- CJC-1295 + Ipamorelin Blend — pre-formulated preparation pairing a GHRHR agonist with a GHS-R1a agonist, for research where both pathways are investigated in the same preparation.
The full category listing is at the GH Secretagogues research catalog.
Research Applications
Published investigations of this compound class span several methodological categories: pituitary endocrinology research using cultured somatotrope preparations with hormone measurement endpoints; receptor-binding kinetics using radiolabeled ligand displacement assays on membranes expressing GHRHR or GHS-R1a; downstream signalling research using cAMP accumulation assays for the GHRHR class and calcium flux measurement for the GHS-R1a class; and enzymatic stability research comparing degradation rates of modified and unmodified sequences in serum or plasma preparations. The DAC and non-DAC pairing, and the Mod GRF (1-29) versus unmodified GRF (1-29) pairing, are the two structural comparisons that appear most often in this literature.
Reconstitution References
Each compound in this category has a concentration reference that converts vial content and diluent volume into resulting solution concentration:
- CJC-1295 NO DAC concentration reference
- CJC-1295 with DAC concentration reference
- Sermorelin concentration reference
- Tesamorelin concentration reference
- Ipamorelin concentration reference
- CJC-1295 + Ipamorelin blend concentration reference
Storage Characteristics
Lyophilized compounds in this category are stable for 24 months or longer at −20°C in sealed vials, protected from light and moisture. The pentapeptide Ipamorelin is more robust in solution than the larger 29- and 44-residue GRF analogs, which are more sensitive to freeze-thaw cycles once reconstituted. Reconstituted aqueous solutions should be aliquoted before freezing. See the peptide storage guide for full reconstitution and handling parameters.
Related Research
- Compound Research Database — full Solira catalog with molecular weights and CAS numbers
- How Solira Tests Every Lot — HPLC and mass spectrometry verification applied to every research peptide lot, including this category
- Peptide Storage Guide — storage and reconstitution practices for lyophilized research peptides
- What Are Research Peptides? — neutral reference on synthesis, characterization and research-supply framing
