Research Context
Our GHRP-6 is a 6-amino-acid synthetic hexapeptide (His-D-Trp-Ala-Trp-D-Phe-Lys-NH₂) engineered as a potent non-selective ghrelin receptor (GHS-R1a) agonist, supplied at >99% HPLC purity for GH-secretion and appetite-regulation research. Frequently referred to in laboratory shorthand as GHRP-6 or Growth Hormone Releasing Peptide-6, this compound is studied for endogenous GH release, appetite stimulation, and metabolic research in controlled laboratory investigations alongside complementary hormonal compounds for comparative endocrine research.
A ghrelin-receptor agonist researched for its role in GH secretion and appetite regulation.
GHRP-6: Mechanism of Action and Endocrine Research Applications
Our GHRP-6 is a 6-amino-acid synthetic hexapeptide (His-D-Trp-Ala-Trp-D-Phe-Lys-NH₂) engineered as a potent non-selective ghrelin receptor (GHS-R1a) agonist, supplied at >99% HPLC purity for GH-secretion and appetite-regulation research. Frequently referred to in laboratory shorthand as GHRP-6 or Growth Hormone Releasing Peptide-6, this compound is studied for endogenous GH release, appetite stimulation, and metabolic research in controlled laboratory investigations alongside complementary hormonal compounds for comparative endocrine research.
Overview
GHRP-6 (frequently referred to as GHRP6 or Growth Hormone Releasing Peptide-6) is a synthetic hexapeptide and a highly potent growth hormone secretagogue (GHS). It functions as a strong ghrelin receptor agonist, specifically binding to the growth hormone secretagogue receptor type 1a (GHS-R1a) in the pituitary gland and hypothalamus to stimulate a robust release of endogenous growth hormone (GH). GHRP-6 is the foundational, original compound of the GHRP family — characterized by its non-selective nature, significantly elevating cortisol, prolactin, and aldosterone levels alongside GH. The most prominent and well-documented effect of GHRP-6 in research models is profound appetite stimulation (orexigenic effect), which occurs through strong activation of neuropeptide Y (NPY) pathways in the arcuate nucleus of the hypothalamus. Consequently, GHRP-6 is primarily utilized in research protocols where maximum GH release and increased caloric intake are the specific endpoints being studied. GHRP-6 is frequently referenced alongside Ipamorelin and GHRP-2 in comparative GHRP research.
Key Research Findings (At a Glance)
| Parameter | Summary |
|---|---|
| Peptide Structure | 6 amino acids (His-D-Trp-Ala-Trp-D-Phe-Lys-NH₂) |
| Origin | Synthetic ghrelin receptor agonist (GHS-R1a) |
| Primary Mechanism | GHS-R1a agonism, endogenous GH release, NPY-mediated appetite stimulation |
| Key Research Areas | Growth hormone secretion, appetite/feeding behavior, metabolic research, cardiovascular pathways |
| Distinguishing Feature | Maximum GH potency; strongest appetite stimulation of any GHRP |
| Key Differentiator from GHRP-2 | Less selective; significantly stronger appetite stimulation; higher cortisol/prolactin elevation |
| Key Differentiator from Ipamorelin | Non-selective vs. highly selective; potent orexigenic effects |
| Typical Research Dosing Scale | 100–300 mcg per administration (subcutaneous) |
| Common Combinations | CJC-1295 No DAC (requires careful monitoring) |
| Intended Use | Laboratory research only – not for human or veterinary consumption |
GHRP-6 Mechanism of Action: Ghrelin Receptor Agonism and NPY Stimulation
GHRP-6 binds to the growth hormone secretagogue receptor (GHS-R), also known as the ghrelin receptor, which is expressed in the pituitary gland and hypothalamus. This binding mimics the action of endogenous ghrelin, triggering a potent signaling cascade that stimulates the synthesis and massive release of growth hormone from somatotroph cells in the anterior pituitary.
Unlike highly selective GHRPs, GHRP-6 demonstrates low selectivity for the somatotropic axis. Research models show GHRP6 causes significant, dose-dependent elevation of cortisol and prolactin. While this makes it less ideal for protocols requiring a "clean" hormonal profile, it provides valuable data for researchers studying the interplay between GH, stress hormones, and lactogenic pathways.
Growth Hormone Releasing Peptide-6 uniquely crosses the blood-brain barrier to directly stimulate the arcuate nucleus of the hypothalamus. This stimulation triggers the release of neuropeptide Y (NPY) and agouti-related peptide (AgRP), which are the most potent known drivers of hunger and food intake in mammalian models. This profound orexigenic effect is a defining characteristic of GHRP-6 research.
GHRP-6 vs. GHRP-2 vs. Ipamorelin: Comparative GHRP Research Analysis
Researchers frequently compare these three growth hormone releasing peptides to understand the trade-offs between GH release potency, selectivity, and side effect profiles.
| Feature | GHRP-6 | GHRP-2 | Ipamorelin (Ipa) |
|---|---|---|---|
| Peptide Type | Hexapeptide (6 amino acids) | Hexapeptide (6 amino acids) | Pentapeptide (5 amino acids) |
| Receptor Target | GHS-R1a (ghrelin receptor) | GHS-R1a (ghrelin receptor) | GHS-R1a (ghrelin receptor) |
| GH Release Potency | Very High | High | Moderate |
| Selectivity | Non-selective (significant cortisol/prolactin elevation) | Moderately selective (mild cortisol/prolactin elevation) | Highly selective (minimal cortisol/prolactin effects) |
| Appetite Stimulation | Strong (potent ghrelin-mimetic/NPY activation) | Mild | Minimal |
| Water Retention Risk | High | Moderate | Low |
| Primary Research Application | Maximum GH release, appetite/feeding behavior research | Balanced potent GH release, body composition studies | Clean GH elevation, aging research, combination protocols |
| Typical Research Dosing Scale | Micrograms (100-300 mcg) | Micrograms (100-300 mcg) | Micrograms (100-300 mcg) |
| Common Combinations | CJC-1295 No DAC (requires careful monitoring) | CJC-1295 No DAC, Sermorelin | CJC-1295 No DAC, Sermorelin, Tesamorelin |
Note: While all three peptides stimulate GH release through ghrelin receptor activation, GHRP-6 is distinguished by its maximum potency and profound appetite-stimulating effects. Researchers must carefully monitor cortisol and prolactin levels when utilizing GHRP-6. Formulation ratios and purity metrics may vary by batch.
GHRP-6 Chemical Specifications (Acetate Salt)
| Specification | Value |
|---|---|
| Synonyms | GHRP-6, GHRP6, Growth Hormone Releasing Peptide-6 |
| Peptide Sequence | H-DL-His-DL-Trp-DL-Ala-DL-Trp-DL-Phe-DL-Lys-NH2 |
| Peptide Length | 6 amino acids (Hexapeptide) |
| Key Structural Notes | 6-amino-acid synthetic hexapeptide; potent non-selective ghrelin receptor (GHS-R1a) agonist and growth hormone secretagogue |
| Structural Modification Overview | Ghrelin Receptor Agonist: Synthetic hexapeptide that binds to GHS-R1a (ghrelin receptor) in the pituitary and hypothalamus. Maximum GH Potency: Stimulates endogenous growth hormone secretion with the highest potency among GHRPs. Non-Selective Profile: Significantly elevates cortisol, prolactin, and aldosterone alongside GH. Profound Appetite Stimulation: Activates NPY pathways in the arcuate nucleus, producing the strongest orexigenic effect of any GHRP. CD36 Receptor Binding: Exhibits affinity for CD36 receptors involved in cardiovascular and vascular cytoprotective pathways. |
| Base Chain | 6-amino-acid linear synthetic hexapeptide |
| Molecular Formula | C₄₆H₅₆N₁₂O₆ · 3C₂H₄O₂ |
| Molecular Weight | ~1053.17 g/mol |
| SMILES | O=C(N[C@H](CC1=CC=CC=C1)C(N[C@H](C(N)=O)CCCCN)=O)[C@@H](NC([C@H](C)NC([C@H](NC([C@H](CC2=CN=CN2)N)=O)CC3=CNC4=C3C=CC=C4)=O)=O)CC5=CNC6=C5C=CC=C6.CC(O)=O.CC(O)=O.CC(O)=O |
| SMILES Note | SMILES string may or may not include the acetate counterion. Full structural details are available via PubChem CID 4345065. |
| Purity | ≥99% by HPLC |
| Form | Lyophilized white powder |
Note: Formulation ratios and purity metrics may vary by batch. Always refer to the batch-specific Certificate of Analysis (COA) included with your order for exact composition and laboratory-verified specifications.
GHRP-6: Acetate Salt vs. Free Base Comparison for Researchers
For researchers reviewing the literature, GHRP-6 is available as both a freebase and an acetate salt form. The acetate salt form is the standard research-grade version supplied by SCYRX, offering enhanced solubility and stability for laboratory applications. The freebase reference data is provided below for comparative literature review purposes only.
| Specification | Acetate Salt (SCYRX Supply) | Free Base (Reference Only) |
|---|---|---|
| Number of Amino Acids | 6 | 6 |
| Molecular Formula | C₄₆H₅₆N₁₂O₆ · 3C₂H₄O₂ | C₄₆H₅₆N₁₂O₆ |
| Molecular Weight | ~1053.17 g/mol | 873.03 g/mol |
| CAS Number | 145177-42-0 | 87616-84-0 |
| PubChem CID | 4345065 | 5486806 |
| Form | Acetate Salt | Free Base |
Note: Molecular weights for acetate salt forms are approximate and may vary depending on the number of bound acetate molecules (x) in the salt complex. Values provided are based on the peptide core plus acetate counterions and should be used as a reference for research purposes only. Always refer to the batch-specific Certificate of Analysis (COA) for exact molecular weight verification.
Storage and Stability
Lyophilized GHRP-6 should typically be stored at -20°C in a tightly sealed container, protected from light and moisture. Under these conditions, it generally remains stable for up to 24 months from the manufacture date.
GHRP-6 can typically be shipped at room temperature for short periods (up to two weeks) without significant degradation, making it suitable for standard shipping methods.
Once reconstituted with bacteriostatic water, the solution should be refrigerated at 2-8°C and typically used within 28 days. Researchers should avoid repeated freeze-thaw cycles and vigorous shaking to maintain peptide integrity.
Research Dosing Considerations
In preclinical research models, GHRP-6 is evaluated in microgram (mcg) quantities. Administration is most frequently via subcutaneous injection. Due to its potent effects on hunger signaling, it is often studied in protocols examining both growth hormone pulsatility and appetite regulation. Researchers typically use reconstitution volumes of 1–3 mL for precise measurement.
GHRP-6 is typically reconstituted with bacteriostatic water. Because it is dosed in microgram amounts in research models (commonly 100mcg, 200mcg, or 300mcg protocols), researchers typically use reconstitution volumes of 1–3mL to allow for precise measurement with insulin syringes.
In research protocols, GHRP6 is often administered subcutaneously, though its potent side effect profile requires careful monitoring of stress and lactogenic hormones. Investigators studying comprehensive endocrine protocols sometimes research GHRP-6 alongside GHRH analogs such as CJC-1295 No DAC, where the combination produces massive synergistic GH release with compounded effects on cortisol and prolactin.
GHRP-6 Research FAQ
Q: Is GHRP-6 approved for human use or available for personal consumption?
A: No. GHRP-6 sold by SCYRX is supplied strictly as a research-grade compound for in vitro and preclinical laboratory investigation. It is not intended for human consumption, therapeutic application, or any in vivo human use. All material is sold for laboratory research only.
Q: What is the primary mechanism of GHRP-6 in endocrine research?
A: GHRP-6 is a synthetic hexapeptide that acts as an agonist of the growth hormone secretagogue receptor (GHS-R), also known as the ghrelin receptor. By binding to this receptor in the pituitary and hypothalamus, it stimulates a significant release of endogenous growth hormone and strongly activates hunger signaling pathways.
Q: How does GHRP-6 differ from GHRP-2?
A: While both are ghrelin mimetics, GHRP-6 is generally considered to have a stronger effect on appetite stimulation (hunger) compared to GHRP-2. GHRP-2 is often preferred in research where maximum GH potency is desired with slightly less impact on hunger signals, whereas GHRP-6 is the standard for studying ghrelin-mediated appetite effects.
Q: Why is GHRP-6 frequently compared to Ipamorelin?
A: GHRP-6 is a non-selective secretagogue that can elevate cortisol, prolactin, and aldosterone levels alongside GH, whereas Ipamorelin is highly selective and does not significantly affect these other hormones. Researchers compare them to study the trade-offs between potent ghrelin-mimetic effects (GHRP-6) and hormonal selectivity (Ipamorelin).
Q: Does GHRP-6 cause significant side effects in research models?
A: Research indicates that GHRP-6 can cause transient elevations in cortisol, prolactin, and aldosterone. It is also well-known for stimulating significant appetite and may cause mild water retention or flushing at the injection site. These effects are dose-dependent and are important variables monitored in comparative endocrine studies.
Q: Can GHRP-6 be stacked with CJC-1295 in research protocols?
A: Yes. Combining a GHRP (like GHRP-6) with a GHRH analog (like CJC-1295) is a common strategy to study synergistic GH release. This combination targets two different receptors in the somatotropic axis, often resulting in a much higher amplitude of GH pulses than either compound used alone.
Related Products
Researchers studying GHRP-6 frequently reference the following hormonal and performance compounds in companion protocols:
Scientific References and Citations
- Bowers CY, Momany FA, Reynolds GA, Hong A. On the in vitro and in vivo activity of a new synthetic hexapeptide that acts on the pituitary to specifically release growth hormone. Endocrinology. 1980;106(3):663-667. doi:10.1210/endo-106-3-663
- Cheng K, Chan WW, Barretto B, et al. Demonstration and characterization of the specific binding of growth hormone-releasing peptides to rat anterior pituitary and hypothalamic membranes. Biochem Biophys Res Commun. 1989;160(1):625-631. doi:10.1016/0006-291x(89)92592-6
- Bowers CY. Growth hormone-releasing peptide (GHRP). Cell Mol Life Sci. 1997;53(7):511-519. doi:10.1007/s000180050046
- Tannenbaum GS, Epelbaum J, Bowers CY. Interrelationship between the novel peptide ghrelin and somatostatin/growth hormone-releasing hormone in regulation of pulsatile growth hormone secretion. Endocrinology. 2003;144(3):967-974. doi:10.1210/en.2002-220978
- Wren AM, Small CJ, Ward HL, et al. The novel hypothalamic peptide ghrelin stimulates food intake and growth hormone secretion. Endocrinology. 2000;141(11):4325-4328. doi:10.1210/endo.141.11.7873
- Arvat E, Di Vito L, Lanfranco F, et al. New insights into the endocrine activities of growth hormone-releasing peptides in humans. J Endocrinol Invest. 2000;23(6 Suppl):3-12.