# GHRP-2

> Second-generation synthetic GHRP; a potent ghrelin-receptor agonist approved in Japan as a diagnostic for GH deficiency.

- Also known as: Pralmorelin, KP-102, GPA-748
- Class: Growth Hormone
- FDA approved: No
- Canonical page: https://americanpeptide.com/catalog/ghrp-2

## Overview

GHRP-2 (pralmorelin) is a synthetic hexapeptide growth-hormone secretagogue that activates the GHS-R1a (ghrelin) receptor on pituitary somatotrophs. More potent than its predecessor GHRP-6, it is one of the very few GHRPs to reach regulatory approval anywhere — used in Japan as a single-injection diagnostic test of pituitary GH reserve.

GHRP-2 is a second-generation growth-hormone-releasing peptide, developed after GHRP-6 as researchers tuned the original hexapeptide for greater potency. Like the rest of the family it activates the ghrelin receptor (GHS-R1a) on pituitary somatotrophs, driving a discrete pulse of endogenous growth hormone rather than supplying GH directly.

It occupies an unusual place among research GHRPs: it is actually an approved drug in Japan (as pralmorelin), where a single injection is used to test whether the pituitary can release GH — a diagnostic for growth-hormone deficiency. It is not FDA-approved in the United States. Compared with GHRP-6 it releases more GH per dose and provokes noticeably less of GHRP-6’s hallmark hunger, though it is less selective than ipamorelin and can transiently raise cortisol and prolactin.

## Mechanism

GHS-R1a (ghrelin receptor) agonism → pulsatile GH release.

## Chemistry

| Property | Value |
| --- | --- |
| Molecular formula | C45H55N9O6 |
| Molecular weight | 817.99 Da |
| CAS number | 158861-67-7 |
| PubChem CID | [6918245](https://pubchem.ncbi.nlm.nih.gov/compound/6918245) |

## Sequence

```
D-Ala-D-2-Nal-Ala-Trp-D-Phe-Lys-NH2
```

## Research areas

Studied in: GH secretion studies, GH-deficiency diagnostics, Pituitary function.

Guides on this site:

- [Growth Hormone & Body Composition](https://americanpeptide.com/research-areas/growth-hormone-axis): Secretagogues studied for GH release, IGF-1, and body composition.

## Key research

- Potent GH release — a second-generation GHRP engineered from GHRP-6 for greater potency; releases GH via GHS-R1a with a stronger response per dose.
- Approved diagnostic (Japan) — marketed as pralmorelin for a single-injection test of pituitary GH reserve; one of the very few GHRPs approved anywhere.
- Less appetite than GHRP-6 — retains ghrelin-receptor agonism but with markedly less of the acute hunger GHRP-6 is known for.
- Cortisol / prolactin — less selective than ipamorelin: at higher doses it can transiently raise ACTH, cortisol, and prolactin.
- Not FDA-approved — a research compound in the US; commonly studied alongside a GHRH analog (CJC-1295 / sermorelin) for complementary, pulse-preserving release.

## Storage, handling & synthesis

**Synthesis.** A hexapeptide amide with two D-amino acids and an unnatural D-2-naphthylalanine at position 2. The chain is short and assembles cleanly by solid-phase synthesis; the quality-defining steps are sourcing and coupling the specialty D-2-Nal building block, controlling racemization at the D-residues, and achieving clean C-terminal amidation.

## FAQs

### What is GHRP-2?

GHRP-2 (pralmorelin) is a synthetic hexapeptide that stimulates the pituitary to release growth hormone by activating the ghrelin receptor. In Japan it is an approved diagnostic for GH deficiency.

### How is GHRP-2 different from GHRP-6?

GHRP-2 is the more potent, more refined successor: it releases more GH per dose and causes much less of the sharp hunger GHRP-6 is known for.

### How does it compare with ipamorelin?

Both are GHRPs, but ipamorelin is prized for releasing GH with minimal cortisol or prolactin; GHRP-2 is more potent yet less selective.

### Is GHRP-2 FDA-approved?

No. It is approved in Japan as a diagnostic (pralmorelin) but is not FDA-approved; in the US it is a research compound. This page is a research and educational reference.

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Source: AmericanPeptide.com — https://americanpeptide.com/catalog/ghrp-2
Data license: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Attribution: AmericanPeptide.com.
Research reference only — computational and educational content, not medical advice.