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Ipamorelin | CAS: 170851-70-4

CAS Number:
170851-70-4
Chemical Classification:
Research peptide

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Among selective growth hormone secretagogues, ipamorelin (CAS 170851-70-4) is valued for activating the ghrelin receptor with minimal impact on cortisol or prolactin axes in standard research concentrations. The pentapeptide's compact structure simplifies dose calibration in vitro and keeps reconstitution volumes low for in vivo bolus designs. Experimental priorities differ: some laboratories map GH release kinetics alone, while others embed the secretagogue within broader endocrine challenge batteries. Common scenarios include overnight GH sampling in rodent models, GH3 cell-line secretion assays, and pituitary explant perifusion with somatostatin co-treatment. Supplied at research grade with COA, LC-MS, HPLC, and NMR characterization—not for therapeutic application.

CAS
170851-70-4
Molecular Formula
C38H49N9O5
Molecular Weight
711.9 g/mol
Purity
≥98%
Appearance
White lyophilized powder
Storage
Store at -20°C

Analytical Documentation

COA✓ Available
LC-MS✓ Available
HPLC✓ Available
NMR✓ Available

Research Inquiry

Overview

Ipamorelin is a synthetic pentapeptide growth hormone secretagogue belonging to the ghrelin mimetic class, selectively activating the ghrelin receptor (GHS-R1a) without significant elevation of cortisol or prolactin in standard rodent research paradigms. Its structure derives from growth hormone-releasing peptide scaffolds optimized for receptor selectivity and minimal off-target endocrine effects compared with earlier hexapeptide secretagogues. Ipamorelin serves as a pharmacological tool for investigating ghrelin receptor signaling in pituitary somatotrophs, hypothalamic arcuate neurons, and peripheral GHS-R expressing tissues. The compound enables clean dissection of ghrelin pathway contributions to GH pulsatility distinct from GHRH receptor agonists such as tesamorelin or cjc-1295 in endocrine research laboratories. Supplied at ≥98% purity (C38H49N9O5; 711.9 g/mol), this material supports controlled laboratory investigation under research-use-only conditions.

Mechanism of Action

Ipamorelin binds GHS-R1a and activates Gq and Gs signaling pathways depending on cell context, elevating intracellular calcium and cAMP in somatotrophs to trigger GH vesicle fusion. Arcuate nucleus ghrelin receptor populations modulate GHRH and somatostatin release, indirectly shaping GH pulse architecture in research animals. Unlike GHRH analogs, ipamorelin does not increase GH gene transcription substantially but acutely stimulates secretion. Ipamorelin avoids significant ACTH or prolactin release in published rodent studies at research doses, distinguishing it from non-selective GHS compounds. Its mechanism supports comparative secretagogue research in metabolic and aging biology models.

Receptor Binding & Signaling

Ipamorelin exhibits high selectivity for GHS-R1a over GHS-R1b and unrelated GPCRs in standard binding panels. Affinity is in the low nanomolar range in cell-based functional assays. No meaningful GLP-1R, GHRHR, or melanocortin receptor activation occurs at research concentrations. Species ortholog differences in GHS-R1a affect potency between human cell lines and rodent in vivo studies.

Research Applications

Selective GH release assays

Ipamorelin induces GH release in pituitary cell cultures and conscious rodent models with minimal confounding prolactin or cortisol elevation, enabling selective growth axis studies. Automated blood sampling captures pulse dynamics after bolus or infusion administration in research protocols. Comparison with GHRH analogs reveals additive versus synergistic secretagogue interactions. These experiments advance ghrelin receptor pharmacology in endocrine research.

GHS-R1a signaling biochemistry

Heterologous cells expressing GHS-R1a measure calcium flux, ERK activation, and beta-arrestin recruitment following ipamorelin stimulation. Structure-activity studies on pentapeptide variants use ipamorelin as a reference full agonist. Antagonists such as D-Lys3-GHRP-6 validate receptor specificity. Results support GPCR biophysics research on class A secretagogue receptors.

Bone and musculoskeletal research models

GH axis stimulation via ipamorelin is employed in rodent research examining chondrocyte proliferation, osteoblast markers, and local IGF-1 expression in bone tissue under controlled study designs. GH receptor blockade confirms downstream mediator involvement. Studies focus on growth hormone physiology in skeletal research without clinical bone disease claims.

Metabolic cross-talk with adipose tissue

Researchers use ipamorelin to probe GH effects on adipose lipolysis and substrate utilization in pair-fed animal models. Indirect calorimetry combined with GH sampling separates acute secretagogue effects from chronic axis remodeling. Ipamorelin supports exploration of ghrelin-GH-adipose communication in metabolic endocrinology laboratories.

Molecular Information

Sequence & Chain Summary

Aib-His-D-2-Nal-D-Phe-Lys-NH2 (pentapeptide).

Modification Type

C-terminal amide; N-terminal Aib for stability.

Structural Notes

Ipamorelin is a small linear peptide amenable to standard RP-HPLC purification with mass confirmation by MALDI-TOF or ESI-MS. The D-amino acid residues and naphthylalanine side chain confer protease resistance and receptor selectivity. Aqueous solubility is good at acidic pH. Purity assessment relies on HPLC peak area integration at ≥98% specification. Batch-specific molecular characterization—including mass confirmation and purity profiling—is available through COA, LC-MS, HPLC, and NMR documentation supplied with Ipamorelin.

Molecular Formula
C38H49N9O5
Molecular Weight
711.9 g/mol
Purity Specification
≥98%

Experimental Notes

Stability

Lyophilized ipamorelin stores well at −20°C desiccated. Reconstituted solutions are stable for short bench periods; aliquot and freeze for longer retention. Minimal aggregation risk due to small size. Protect from oxidation during prolonged ambient exposure. Lyophilized Ipamorelin should be protected from repeated freeze-thaw cycles, moisture, and prolonged exposure to ambient light where applicable. Analytical integrity is best preserved when material is stored under the conditions specified on the certificate of analysis.

Storage Conditions

Store at -20°C. Ipamorelin is supplied as white lyophilized powder. For long-term archival storage in research inventories, maintain sealed containers with desiccant where recommended and document lot numbers for traceability across experimental runs.

Laboratory Handling

Dissolve in sterile water or dilute acetic acid. Avoid adsorption by using low-bind tubes for nanomolar stocks. Calculate doses by molecular weight 711.9 g/mol. Document batch lot for traceability across in vivo study cohorts. Reconstitute only with appropriate research-grade solvents compatible with your assay format. Allow vials to reach equilibrium before opening, work under clean bench conditions, and label all working solutions with concentration, date, and researcher ID per institutional SOPs.

Related Peptides

Growth Hormone Peptides →Peptide CAS database →

Frequently Asked Questions

Research-focused answers about Ipamorelin. For laboratory use only — not medical advice.

What is Ipamorelin used for in research?
Ipamorelin is intended for research on ghrelin receptor biology and growth hormone secretagogue pathways in qualified laboratories. It is not for human or veterinary administration or performance enhancement applications.
How does Ipamorelin work biologically?
Ipamorelin activates ghrelin receptor GHS-R1a on somatotrophs and hypothalamic neurons, triggering GH release with minimal prolactin or cortisol elevation in standard rodent research models compared with less selective secretagogues.
What receptors does Ipamorelin interact with?
Primary target is growth hormone secretagogue receptor type 1a (GHS-R1a). Selectivity over GHS-R1b, GHRHR, and unrelated receptors defines its utility as a clean secretagogue tool in endocrine research.
Is Ipamorelin stable at room temperature?
Lyophilized ipamorelin stores well at −20°C desiccated. Reconstituted solutions are stable for short bench periods; aliquot and freeze for longer retention. Minimal aggregation risk due to small size. Protect from oxidation during prolonged ambient exposure. For short-term laboratory workflows, minimize time at room temperature and return unused material to recommended storage promptly. Ipamorelin is not formulated for ambient long-term storage.
What is the recommended storage condition for Ipamorelin?
Store at -20°C. Store lyophilized material in a dedicated −20°C freezer, protect from moisture ingress, and avoid repeated temperature cycling. Reconstituted solutions should be aliquoted and frozen if not used within the validated window of your internal stability study.