GHRP-2 and GHRP-6 are both hexapeptide GHSR (ghrelin) receptor agonists — but their published selectivity and research applications diverge. Full Kiwi Peps comparison reference.
GHRP-2 vs GHRP-6 is a common comparison in GH-axis research because both are hexapeptide agonists of the growth-hormone secretagogue receptor (GHSR-1a / ghrelin receptor). Both compounds pre-date ipamorelin as GHSR reference tools and remain widely cited in published rodent and in-vitro literature. Their divergence — GH release magnitude, appetite modelling and selectivity — is what determines which is picked for a given research question.
GHRP-2 vs GHRP-6 at a glance
| Attribute | GHRP-2 | GHRP-6 |
|---|---|---|
| Sequence | D-Ala-D-2-Nal-Ala-Trp-D-Phe-Lys-NH₂ | His-D-Trp-Ala-Trp-D-Phe-Lys-NH₂ |
| Class | Hexapeptide GHSR agonist | Hexapeptide GHSR agonist |
| Published GH release magnitude | Higher | Moderate |
| Appetite modelling (rodent) | Modest | Pronounced — canonical appetite-model reference |
| Reference research use | GH-axis PK comparator | Ghrelin/appetite modelling comparator |
| Modern selectivity comparator | Ipamorelin | Ipamorelin |
How the two compounds are used in research
- GHRP-2 is cited as a reference for magnitude of GH pulse in published PK datasets.
- GHRP-6 is cited in rodent appetite / feeding-behaviour research as a ghrelin-mimetic reference.
- Both are documented as legacy GHSR agonists — modern selectivity comparisons default to ipamorelin.
- Both are frequently paired with GHRH analogs (Mod GRF 1-29, CJC-1295) in published dual-axis studies.
Which reference fits which research question?
| Research question | Reference compound |
|---|---|
| Magnitude of GH release from GHSR activation | GHRP-2 |
| Ghrelin / appetite-model characterisation | GHRP-6 |
| Highly selective GHSR agonism | Ipamorelin |
| Historical GHSR reference for comparator panels | GHRP-2 or GHRP-6 |
- Batch identifier and synthesis date traceable to the lot record
- HPLC purity ≥98% (typically ≥99% for peptides under 30 residues)
- LC-MS confirmed monoisotopic or average mass within ±0.5 Da of theoretical
- Counterion identity and content (acetate or trifluoroacetate) reported
- Bacterial endotoxin and residual solvents per the analytical method
GHRP-2 vs GHRP-6 FAQ
What is the difference between GHRP-2 and GHRP-6?
Both are hexapeptide GHSR agonists. GHRP-2 has a higher published GH-release magnitude; GHRP-6 has a much stronger published appetite-modelling signal in rodent research.
Is GHRP-2 or GHRP-6 more selective?
Neither is highly selective by modern standards — ipamorelin is the reference GHSR agonist when receptor selectivity is the primary research variable.
Can GHRP-2 or GHRP-6 be blended with CJC-1295?
Published research pairs both with GHRH analogs such as Mod GRF 1-29 or CJC-1295 to model dual-axis GH release, though ipamorelin has largely superseded them in modern blend research.
Where can New Zealand researchers buy GHRP-2 and GHRP-6?
Kiwi Peps supplies GHRP-2 and GHRP-6 at ≥98% HPLC purity with third-party COA and same-day domestic dispatch. Research use only.
