GH Secretagogues

GHRP-2

Also known as: Pralmorelin

Molecular Identifiers

Molecular Formula

C45H55N9O6

CAS Number

158861-67-7

PubChem CID

6918245

Molecular Weight

817.97 Da

Overview

Second-generation GH-releasing peptide with moderate ghrelin activity. Strong GH release with moderate appetite increase. Potent when combined with GHRH analogs.

The main clinical effect of interest for GHRP-2 is a strong pulse of endogenous GH release via GHS-R1a receptor agonism, with a moderate appetite increase from ghrelinergic activity. It is commonly combined with GHRH analogs (CJC-1295, sermorelin) for synergy, aimed at mass gain, body composition, and recovery support. Higher doses tend to raise cortisol and prolactin, which limits dose escalation.

GHRP-2 has no broad regulatory approval — it was evaluated clinically as pralmorelin for GH deficiency diagnostic testing in some jurisdictions, but without consolidated FDA, EMA, or ANVISA approval. It is generally dispensed by compounding pharmacies as off-label use in 8–12 week protocols, in up to three subcutaneous administrations per day (morning, post-workout, bedtime). GH secretagogues are banned by WADA at all times.

Within the GHRP family, GHRP-2 sits between hexarelin (more potent but more desensitizing, with greater cortisol/prolactin elevation), GHRP-6 (similar potency but with marked appetite stimulation), and ipamorelin (cleaner profile, lower potency, no significant cortisol or prolactin rise). Unlike GHRH analogs (sermorelin, CJC-1295, tesamorelin) it acts on GHS-R1a rather than the GHRH receptor, which is why it is typically stacked with one of them rather than substituting; the oral MK-677 acts on the same receptor with much longer duration.

Extended notation: D-Ala-D-2-Nal-Ala-Trp-D-Phe-Lys-NH₂

Contains D-amino acids and non-natural amino acid (D-Ala, D-2-Nal, D-Phe)

Half-life

~25-30 minutes

Administration Route

Subcutaneous

Category

GH Secretagogues

Mechanism of Action

  • GHS-R1a receptor agonist
  • Potent dose-dependent GH release
  • Moderate ghrelin activity (appetite increase)
  • Synergism with exogenous GHRH

Dosage Protocol

Data compiled from the literature. This does not constitute medical advice.

Parameter Value
Dose 100-300 mcg per injection
Frequency 2-3 times per day
Timing Morning, post-workout and before bedtime
Duration 8-12 weeks

Reported Side Effects

Adverse effects described in the literature. Severity and frequency vary between individuals.

  • Increased appetite
  • Water retention
  • Tingling
  • Elevated cortisol/prolactin

Product Properties

Purity >99%
Appearance White lyophilized powder
Solubility Soluble in water and bacteriostatic water
Source Solid-phase peptide synthesis (SPPS)
Storage Lyophilized: -20°C for up to 2 years, 2-8°C for up to 6 months. Reconstituted: 2-8°C for up to 4 weeks. Protect from light and moisture. Avoid repeated freeze-thaw cycles.

Presentations & Preparation

Vials of GHRP-2 found in the research market:

5 mg10 mg

Reconstitution

  • Diluent: Bacteriostatic water
  • Volume: 2 ml per 5 mg vial
  • Inject the diluent slowly against the vial wall
  • Gently swirl until fully dissolved
  • Never shake

Storage

  • Lyophilized: Room temperature or refrigerated
  • Reconstituted: Refrigerated 2-8°C (up to 30 days)
  • Protect from direct light
  • Do not freeze after reconstitution
Reconstitution Calculator

Scientific Studies

Published studies on GHRP-2.

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