Overview

GHRP-2 is a synthetic hexapeptide derived from met-enkephalin structure that functions as a potent GHS-R1a agonist. It is one of the most potent GHRPs in terms of GH release amplitude, capable of stimulating pulsatile GH secretion by over threefold compared to GHRH alone. GHRP-2 is approved in some countries for diagnostic testing of GH secretory capacity (as pralmorelin). It stimulates both GH and to a lesser extent ACTH and cortisol, making it less selective than ipamorelin.

Mechanism of Action

GHRP-2 activates GHS-R1a receptors with high affinity, triggering intracellular calcium signaling and protein kinase C activation in pituitary somatotrophs. This drives GH gene transcription and pulsatile GH secretion. Studies show it may stimulate anterior pituitary GH production up to 181 times baseline, with IGF-1 levels rising from ~100 to ~180 mcg/L. It also stimulates ghrelin release, appetite, and modest ACTH/cortisol elevation.

Potential Benefits

  • Among the most potent GH-releasing peptides by amplitude
  • IGF-1 elevation supporting muscle growth and recovery
  • Pulsatile GH secretion mimicking physiological patterns
  • Used as a diagnostic agent for GH deficiency evaluation
  • Potential muscle hypertrophy and anti-atrophy effects

Dosage Protocols

The following reflects doses used in published research studies. This is not medical advice. Consult a qualified healthcare professional.

Typical Range100-300 mcg/dose, 2-3x/day
Beginner100 mcg once daily at bedtime
Intermediate200 mcg twice daily
Advanced300 mcg 2-3x/day (morning, pre-workout, bedtime)
Cycle Duration6-8 weeks
Cycle Off4 weeks (to prevent tachyphylaxis)

GHRP-2 is more potent than GHRP-6 but also stimulates cortisol and ACTH. Fasted state required for maximal GH response. Doses above 300 mcg do not increase GH output proportionally.

Routes of Administration

Subcutaneous Injection High

Primary route; inject fasted for maximal GH response; avoid dosing within 2 hours of carbohydrate or fat-containing meals

Intramuscular Injection High

Faster peak concentration; may enhance immediate post-workout GH response

Stacking Protocols

Popular research stacks involving GHRP-2:

Potent GH Stack

Maximum GH pulse amplitude for muscle growth

GHRP-2 combined with CJC-1295 can produce 54x normal pulsatile GH secretion in some studies; powerful but may moderately increase cortisol.

Diagnostic GH Protocol

Clinical GH secretory capacity assessment

GHRP-2GHRH

GHRP-2 (Pralmorelin) is approved in Japan for GH deficiency diagnosis; combined with exogenous GHRH for definitive pituitary GH reserve assessment.

Reconstitution

Typical Vial Size5mg, 10mg
BAC Water2ml per 5mg vial
StorageRefrigerate at 2-8°C after reconstitution
Shelf Life28 days refrigerated

Need exact syringe measurements?

Amino Acid Sequence

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

Side Effects & Safety

  • Cortisol and ACTH elevation
  • Appetite stimulation
  • Water retention
  • Flushing or warmth sensation
  • Fatigue

Synergistic Compounds

The following compounds have been studied alongside GHRP-2 for potential complementary or synergistic effects:

CJC-1295IpamorelinGHRH analogs

Learn More

References & Further Reading

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