Research Context
Our GHRP-2 vial is a ghrelin-mimetic research compound supplied at >99% HPLC purity for GH-release and somatotropic-signaling research.
Within the broader landscape of research compounds — colloquially referred to in community forums as compounds or "research peptides" — GHRP-2 is studied for its mechanistic profile in controlled laboratory protocols. Investigators frequently catalog it alongside complementary research compounds when designing comparative or pathway-level studies.
A ghrelin-mimetic peptide investigated for its potent influence on growth-hormone release.
GHRP-2 (Growth Hormone Releasing Peptide-2): Potent Ghrelin Receptor Agonist
GHRP-2 (frequently referred to in research communities as GHRP2 or Growth Hormone Releasing Peptide-2) is a synthetic hexapeptide and a potent growth hormone secretagogue (GHS). It functions as a ghrelin receptor agonist, specifically binding to the growth hormone secretagogue receptor type 1a (GHS-R1a) in the pituitary gland and hypothalamus to stimulate the synthesis and release of growth hormone (GH). GHRP-2 is frequently referenced alongside specific dosage colloquialisms (such as 100mcg, 200mcg, or 300mcg protocols) in research literature.
GHRP-2 occupies a unique position among the GHRP family. It is structurally very similar to Ipamorelin, with the only difference being a single amino acid substitution at position 1 (Alanine instead of α-aminoisobutyric acid). However, this small structural change results in GHRP2 being more potent at releasing GH than Ipamorelin, but less selective, meaning it can cause mild elevation of cortisol and prolactin levels compared to the "cleaner" profile of Ipamorelin.
Growth Hormone Releasing Peptide-2 is also structurally related to the original hexapeptide GHRP-6, but with modifications that significantly reduce its potent appetite-stimulating (orexigenic) effects. GHRP-2 is frequently researched in combination with Growth Hormone Releasing Hormone (GHRH) analogs such as CJC-1295 No DAC, Sermorelin, or Tesamorelin for synergistic "pulse-burst" effects on the somatotropic axis.
GHRP-2 Mechanism of Action: Ghrelin Receptor Agonism and GH Potency
GHRP-2 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 signaling cascade that stimulates the synthesis and release of growth hormone from somatotroph cells in the anterior pituitary. GHRP-2 has higher binding affinity and GH-releasing potency than Ipamorelin, but lower than GHRP-6.
Unlike the highly selective Ipamorelin, GHRP-2 demonstrates moderate selectivity. Research models show that GHRP2 can cause mild to moderate elevation of cortisol (a stress hormone) and prolactin, though significantly less than the non-selective GHRP-6. This moderate selectivity makes Growth Hormone Releasing Peptide-2 a balanced choice for researchers who want potent GH release without the extreme side effects of GHRP-6 or the lower potency of Ipamorelin.
While GHRP-6 is a potent ghrelin-mimetic that strongly stimulates hunger, GHRP-2 has been modified to reduce this effect. Research demonstrates that GHRP-2 can still cause mild appetite stimulation in some models, but it is significantly less pronounced than GHRP-6. This makes GHRP2 more suitable for body composition research where extreme hunger is undesirable.
GHRP-2 vs. Ipamorelin vs. GHRP-6: 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-2 | Ipamorelin (Ipa) | GHRP-6 |
|---|---|---|---|
| Peptide Type | Hexapeptide (6 amino acids) | Pentapeptide (5 amino acids) | Hexapeptide (6 amino acids) |
| Receptor Target | GHS-R1a (ghrelin receptor) | GHS-R1a (ghrelin receptor) | GHS-R1a (ghrelin receptor) |
| GH Release Potency | High | Moderate | Very High |
| Selectivity | Moderately selective (mild cortisol/prolactin elevation) | Highly selective (minimal cortisol/prolactin effects) | Non-selective (significant cortisol/prolactin elevation) |
| Appetite Stimulation | Mild | Minimal | Strong (potent ghrelin-mimetic) |
| Water Retention Risk | Moderate | Low | High |
| Primary Research Application | Balanced potent GH release, body composition studies | Clean GH elevation, aging research, combination protocols | Maximum GH release, appetite research |
| Typical Research Dosing Scale | Micrograms (100-300 mcg) | Micrograms (100-300 mcg) | Micrograms (100-300 mcg) |
| Common Combinations | CJC-1295 No DAC, Sermorelin | CJC-1295 No DAC, Sermorelin, Tesamorelin | CJC-1295 No DAC (less common due to side effects) |
Note: While all three peptides stimulate GH release through ghrelin receptor activation, GHRP-2 is distinguished by its balanced profile—more potent than Ipamorelin but more selective than GHRP-6. Researchers often combine GHRPs with GHRH analogs (such as CJC-1295 or Sermorelin) for synergistic effects. Formulation ratios and purity metrics may vary by batch.
GHRP-2 Chemical Specifications
| Specification | Value |
|---|---|
| Peptide Sequence | H-D-Ala-D-2-Nal-Ala-Trp-D-Phe-Lys-NH₂ |
| CAS Number | 158861-67-7 |
| Synonyms | GHRP-2, GHRP2, Pralmorelin, Growth Hormone Releasing Peptide-2 |
| Molecular Formula | C₄₅H₅₅N₉O₆ |
| Molar Mass | 817.95 g/mol |
| Peptide Length | 6 amino acids (hexapeptide) |
| 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.
Storage and Stability
Lyophilized GHRP-2 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-2 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-2 is evaluated in microgram (mcg) quantities. Administration is most frequently via subcutaneous injection. Due to its potent ghrelin-mimetic properties, it is often studied in protocols examining both growth hormone pulsatility and hunger signaling pathways. Researchers typically use reconstitution volumes of 1–3 mL for precise measurement.
GHRP-2 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, GHRP2 is often administered subcutaneously, frequently in combination with GHRH analogs such as CJC-1295 No DAC, Sermorelin, or Tesamorelin. The combination of a GHRP with a GHRH analog is studied for its ability to produce greater GH release than either compound alone, as they operate through different but complementary signaling pathways.
GHRP-2 Research FAQ
Q: Is GHRP-2 approved for human use or available for personal consumption?
A: No. GHRP-2 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-2 in endocrine research?
A: GHRP-2 is a synthetic hexapeptide that acts as a potent 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 and rapid release of endogenous growth hormone.
Q: How does GHRP-2 differ from GHRP-6?
A: While both are ghrelin mimetics, GHRP-2 is generally considered more potent on a per-milligram basis for GH release. However, GHRP-6 is known for having a stronger effect on appetite stimulation (hunger signaling). GHRP-2 provides a "cleaner" profile for researchers focusing primarily on GH amplitude without extreme hunger effects.
Q: Why is GHRP-2 frequently compared to Ipamorelin?
A: GHRP-2 is a non-selective secretagogue that can elevate cortisol and prolactin 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 maximum GH potency (GHRP-2) and hormonal selectivity (Ipamorelin).
Q: Does GHRP-2 cause significant side effects in research models?
A: Research indicates that GHRP-2 can cause transient elevations in cortisol, prolactin, and aldosterone. It may also stimulate appetite and cause mild water retention. These effects are dose-dependent and are important variables monitored in comparative endocrine studies.
Q: Can GHRP-2 be stacked with CJC-1295 in research protocols?
A: Yes. Combining a GHRP (like GHRP-2) 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-2 frequently reference the following hormonal and performance compounds in companion protocols:
Scientific References and Citations
- Bowers CY. Growth hormone-releasing peptide (GHRP). Cell Mol Life Sci. 1997;53(7):511-519. doi:10.1007/s000180050046
- Bowers CY, Momany FA, Sethumadhavan R, et al. Structure-activity studies of a novel growth hormone-releasing peptide, GHRP-2. J Endocrinol Invest. 1993;16(5 Suppl 1):36-42.
- 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.
- Hataya Y, Akamizu T, Takaya K, et al. A low dose of ghrelin stimulates growth hormone (GH) release synergistically with GH-releasing hormone in humans. J Clin Endocrinol Metab. 2001;86(9):4552. doi:10.1210/jcem.86.9.7856
- Papotti M, Ghigo MC, Catapano D, et al. Growth hormone-releasing peptide binding sites in the human hypothalamus and pituitary. J Clin Endocrinol Metab. 1999;84(8):2856-2863. doi:10.1210/jcem.84.8.5931
- 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