GHRP-2 (Pralmorelin)
GHRP-2 (pralmorelin) — evidence, the Japan diagnostic approval & status

Class: peptide
Synonyms: GHRP-2
Growth Hormone Releasing Peptide-2
INN pralmorelin
developer codes KP-102 / GPA-748
Japanese product GHRP Kaken 100
sequence D-Ala-D-2-Nal-Ala-Trp-D-Phe-Lys-NH₂ (MW ~818 Da). INCI: none
Function tags: GH secretagogue / ghrelin agonist
(approved: GH-deficiency diagnostic)
body composition (off-label)
Overall evidence grade: B
WADA prohibited: yes
WADA note: Sport: WADA-prohibited at all times — Section S2.2 (GH secretagogues).
Last updated: 2026-07-04

In brief: GHRP-2 (pralmorelin) is a ghrelin-receptor agonist and the only GHRP with a regulatory approval — in Japan, as a diagnostic agent for GH deficiency. It reliably raises GH (the most potent GHRP per microgram) with intermediate selectivity — moderate cortisol/prolactin and appetite effects (more than Ipamorelin, less than GHRP-6). But the approval is diagnostic-only; the popular anti-aging / body-composition use is untested in humans. It is banned in sport.

## Identity a synthetic **hexapeptide** (6 amino acids, < 40 aa → peptide), a **ghrelin-receptor (GHS-R1a) agonist** that stimulates GH release from the anterior pituitary. It is the **most potent GHRP per microgram** for GH release, with **intermediate selectivity** — sitting between the non-selective GHRP-6 (#24) and the highly selective Ipamorelin (#17). ## Development & history - Developed in the 1990s as a more potent evolution of **GHRP-6** (Bowers' original GHRP).
- **Approved in Japan (PMDA) as pralmorelin (GHRP Kaken 100)** — a **diagnostic agent** for assessing GH deficiency (the GHRP-2 stimulation test), marketed by Kaken Pharmaceutical since ~2004. This makes GHRP-2 **the only GHRP to achieve regulatory approval by any national authority.**
- Its human evidence base is narrow but real: ~**4 published trials (~170 participants)**, all from Kaken, focused on **diagnostic accuracy**. ## Mechanism (as proposed) a **GHS-R1a (ghrelin-receptor) agonist** on pituitary somatotrophs → GH release; it also **suppresses somatostatin** (a dual stimulatory mechanism) and is **synergistic with GHRH** (co-administration amplifies GH several-fold). Notably, GH release plateaus above ~ while **cortisol and prolactin keep rising** dose-dependently — the basis of its intermediate-selectivity profile.

Evidence grades by outcome:
outcome: GH release (diagnostic)
grade: B
base: Approved diagnostic (Japan) + ~4 human trials (~170)
effect: Consistent dose-dependent GH elevation (peak 15–30 min)
caveat: Real but narrow; diagnostic-focused; single company
outcome: GH-deficiency diagnostic testing (approved, Japan)
grade: B
base: Kaken trials; accuracy competitive with the insulin-tolerance test
effect: Reliable provocative test
caveat: Approved diagnostic use only
outcome: Anti-aging / body composition (the popular use)
grade: F
base: None in humans
effect: Not demonstrated
caveat: Untested for these goals
outcome: Safety
base: Diagnostic use + PK data
effect: Characterised (short-term)
caveat: Raises cortisol/prolactin (moderate) + appetite; long-term unknown; WADA-banned

Legal status:
region: US
status: Not FDA-approved (gray-market)
note: not FDA-approved; has not been through the FDA drug-approval process (503A Category-2 / gray-market for off-label use).
region: EU
status: Not approved
note: not approved.

Cosmetic claims:

Note: Reference entry — not sold here. Notable as the only GHRP with a regulatory approval anywhere — but that approval is a diagnostic one (Japan), not a therapy. No dosing published here.

Sources:
Bowers CY, et al. — foundational GHRP characterisation (the class GHRP-2 descends from).
Kaken Pharmaceutical pralmorelin (GHRP Kaken) diagnostic trials; PMDA approval (Japan).