What GHRP-2 is
GHRP-2, also called pralmorelin, is a synthetic hexapeptide from the growth-hormone-releasing peptide family — the first class of compounds shown to stimulate GH release through a receptor entirely separate from the GHRH receptor. That discovery is historically significant: the receptor these peptides acted on was identified before its natural ligand was, and only later was ghrelin found to be the endogenous agonist. The synthetic compound came first and the hormone was discovered by looking for what else bound its target.
- GHRP-2 (pralmorelin)Synthetic hexarelin-family secretagogue
- GHSR-1aThe ghrelin receptor
- Gq → PLC → Ca²⁺Amplifies endogenous GH pulses
- GH secretion modelsUsed as a diagnostic GH stimulus
Mechanism as described in published research. Nothing here describes an effect in a person — these compounds are supplied for laboratory research use only.
Ghrelin receptor signalling
GHRP-2 is an agonist at the growth hormone secretagogue receptor (GHS-R1a), the ghrelin receptor. Because that receptor sits on a different pathway from the GHRH receptor, GHRP-family compounds and GHRH analogues are routinely combined in study designs to probe whether the axis responds additively.
Where GHRP-2 differs from the more selective ipamorelin is in specificity. The earlier GHRP compounds show measurable activity beyond GH release, including effects on cortisol and prolactin, whereas ipamorelin was developed specifically to remove that cross-activity. In research terms that makes GHRP-2 a broader probe and ipamorelin a cleaner one, and the choice between them is a study-design decision rather than a quality ranking.
What the literature covers
Research areas include:
- GHS-R1a pharmacology — binding and downstream signalling.
- Combination designs with GHRH analogues such as sermorelin and modified GRF(1–29).
- Selectivity comparison against ipamorelin and GHRP-6.
- Receptor deorphanisation history — GHRP compounds as the tools that led to ghrelin.
Identity and verification
GHRP-2 has the molecular formula C45H55N9O6 and a molecular weight of 818.0 g/mol (CAS 158861-67-7). Identifiers matter more here than in most categories: research compounds are sold under trade names, development codes and abbreviations that do not always refer to the same molecule, and a formula is unambiguous where a name is not.
Every lot is tested by an independent laboratory before release. Our certificate library covers the lots currently in stock.
We use two laboratories because purity and identity are different questions. Vanguard Laboratory is ISO/IEC 17025:2017 accredited (A2LA #6377.01.01) and reports chromatographic purity and net quantity with a stated measurement uncertainty. Freedom Diagnostics reports HPLC-UV purity together with LC-MS identity confirmation — the test that catches a substituted compound rather than merely an impure one. A sample can be 99% pure and still be the wrong molecule. How we test →
Handling, reconstitution and storage
GHRP-2 ships lyophilized — freeze-dried to a solid and sealed under vacuum — which is what makes it stable in transit rather than a solution racing a clock. Reconstitute with bacteriostatic water, added slowly down the inside wall of the vial rather than directly onto the powder, then swirled gently. Do not shake: mechanical shear is one of the few things that reliably degrades a peptide in the lab.
Final concentration is a function of the volume added, not of the compound, so the same vial can be prepared at very different concentrations. The reconstitution calculator works out the volume for a target concentration and the reconstitution guide covers the procedure. Store lyophilized vials at −20 °C (−4 °F) protected from light; refrigerate once in solution, and see the storage and stability guide for how long reconstituted material holds.
Common questions
Is GHRP-2 the same as pralmorelin?
Yes. GHRP-2, pralmorelin and KP-102 all refer to the same synthetic hexapeptide.
How does GHRP-2 differ from ipamorelin?
Both are ghrelin-receptor agonists, but ipamorelin was developed for selectivity — the earlier GHRP compounds show measurable activity beyond GH release, including on cortisol and prolactin. GHRP-2 is the broader probe, ipamorelin the cleaner one.
What is the difference between GHRP-2 and GHRP-6?
Both are early hexapeptide secretagogues at the same receptor. They differ in sequence and in relative potency and cross-activity profile; GHRP-6 is the earlier of the two and is more associated with appetite signalling in the literature.
Why are GHRP compounds historically significant?
Their receptor was identified before its natural ligand. Ghrelin was subsequently discovered by searching for the endogenous agonist of the receptor these synthetic peptides were already known to activate.
Where to get it
Buy research-grade GHRP-2 — independently tested, certificate published, shipped from Miami with cold-chain packaging. Current pricing for every size is on the price list, and we ship worldwide.
Research use only
Everything referenced here is supplied strictly for laboratory research. These compounds are not drugs, foods, cosmetics or medical devices, are not for human or veterinary use, and are not approved for diagnostic or therapeutic application. Mechanisms are described as studied in preclinical and laboratory research; nothing above describes dosing, treatment or clinical outcome.
