KDC-MN-076 – Kodiac biolabs

Plain-language summaryIntrigue 60 / 100

GHRP-2 is a synthetic peptide that activates the ghrelin receptor and triggers growth hormone release. It is a stronger growth hormone releaser than ipamorelin but also raises cortisol and prolactin slightly. Not stocked by Kodiac. This monograph is provided for research and educational reference.

Intrigue 0–100 blends mechanism novelty, evidence strength, and translational potential. Kodiac editorial, not peer-reviewed.

Our opinion on this compoundEstablished workhorse

39/100

Solid second-generation GHRP with clinical validation but largely outpaced by cleaner, more selective successors

Look, GHRP-2 is a legitimate compound with a real mechanism and honest clinical use. It’s approved in Japan as a GH stimulation test agent, which is more than most peptides in this library can claim. GHS-R1a agonism is well-characterized, the synergy with GHRH analogs is reproducible across labs, and the pharmacokinetics are understood well enough to design clean experiments around it. For basic GH-axis work, it does exactly what it says.

But here’s the thing: GHRP-2 occupies an awkward middle position in its own class. It came after GHRP-6 and before ipamorelin, and that timeline shows. GHRP-6 still has a niche because its off-target ghrelin receptor effects drive appetite stimulation, which some investigators actually want to study. Ipamorelin has the opposite advantage: far cleaner selectivity, minimal cortisol and prolactin bleed, and a sharper tool for anyone trying to isolate GH-axis pharmacology from the noise. GHRP-2 sits between those two, offering stronger GH output than GHRP-6 but less receptor fidelity than ipamorelin. In practice, most researchers who care about clean GH secretagogue biology reach for ipamorelin. Those who want ghrelin receptor pleiotropy study GHRP-6 or ghrelin itself. GHRP-2 doesnt own either lane.

On the evidence side, theres real multi-lab data, replicated GH stimulation studies, and the diagnostic clinical use that most peptides lack. We’re not calling this single-lab-only territory. The problem is that the evidence base is mature in the wrong direction: most of it is decades old, and recent literature on GHRP-2 specifically is thin. When researchers publish GH secretagogue work now, theyre comparing newer molecules, and GHRP-2 mostly appears as a historical comparator or a positive control.

We think bench value is real but unexceptional. GHRP-2 is a serviceable probe for GHS-R1a biology, and it has the advantage of being widely sourced with decent quality consistency. But its not the tool you pick when you want to ask a sharp, specific question about ghrelin receptor pharmacology. Ipamorelin gives you better receptor selectivity for those experiments. GHRP-2 gives you more raw GH output, which matters if GH pulse amplitude is itself the variable of interest rather than a confound.

Honestly, if you’re building a GHRP-focused program from scratch today, GHRP-2 is probably not your first choice. It earns its place in reference panels and in labs that already have it on the shelf, but its not where the interesting new biology in this space is happening. The overall score reflects a compound with genuine historical significance and solid evidence, that is nonetheless unlikely to surprise a serious investigator or open a research question they couldn’t otherwise pursue.

Novelty: 28
Mechanism promise: 42
In-category differentiation: 28
Evidence quality: 52
Translational signal: 48
Research bench value: 48

Rationale GHRP-2 sits in the middle of the GHRP class: more efficacious than GHRP-6 on GH output, less selective than ipamorelin, and carrying 1990s-era origins that put it squarely in the established-mature bracket. Its clinical diagnostic use in Japan gives it real translational standing, but that distinction does little to differentiate it from ipamorelin, which is the GHRP most serious GH-axis investigators now reach for first.

Growth hormone releasing peptide / ghrelin receptor agonist

A second-generation hexapeptide ghrelin receptor agonist for growth hormone release, characterized by stronger GH stimulation than GHRP-6 with reduced cortisol/prolactin elevation.

Abstract

GHRP-2 (Pralmorelin; D-Ala-D-2-Naphthyl-Ala-Ala-Trp-D-Phe-Lys-NH2; CAS 158861-67-7; molecular formula C45H55N9O6; molecular weight 817.97) is a second-generation growth hormone releasing peptide developed in the 1990s as a synthetic ghrelin receptor (GHS-R1a) agonist. The compound stimulates pituitary GH release through a mechanism distinct from GHRH (different receptor; synergistic when combined with GHRH or GHRH analogs). GHRP-2 produces robust GH pulses approximately 2 to 5 times baseline with parenteral administration. Pharmacokinetics: plasma half-life 15 to 60 minutes; subcutaneous and intravenous routes; oral bioavailability poor due to peptidase degradation. The compound is used clinically in Japan as a GH stimulation test. Compared with GHRP-6, GHRP-2 produces stronger GH release with reduced cortisol and prolactin elevation. Compared with ipamorelin, GHRP-2 has higher GH efficacy but less receptor selectivity. Research-grade doses are typically 100 to 300 micrograms subcutaneously per administration, often combined with a GHRH analog.

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The full reference document covers compound identification, discovery and developmental history, mechanism of action, pharmacokinetics, sourcing and quality verification, and a curated reference list. Embedded inline below; download for offline reading.

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FOR RESEARCH USE ONLY. Not for medical, diagnostic, or therapeutic purposes. Not for human consumption. All information is provided for research and educational purposes only.

Tag: KDC-MN-076

GHRP-2

Abstract

Read the full monograph