Skip to content
The Peptide Effect
preclinicalGrowth Hormone

GHRP-2

Also known as: Growth Hormone Releasing Peptide-2, Pralmorelin, KP-102, GHRP-2 Acetate

GHRP-2 is a synthetic hexapeptide growth hormone secretagogue that acts on the ghrelin/GHS receptor to stimulate potent growth hormone release from the pituitary. It is considered one of the strongest GHRPs for GH output, producing a more robust GH response per dose than GHRP-6 while causing less appetite stimulation. However, like GHRP-6 and hexarelin, it is not selective — it also elevates cortisol and prolactin. GHRP-2 (under the name pralmorelin) is approved in Japan as a diagnostic agent for GH deficiency.

Key Facts

Mechanism
GHRP-2 binds to the growth hormone secretagogue receptor (GHS-R1a) on pituitary somatotrophs, triggering intracellular calcium release and GH secretion. It also acts at the hypothalamic level, suppressing somatostatin (the GH-inhibiting hormone) and stimulating GHRH release, creating a dual mechanism for amplified GH output. GHRP-2 activates the ghrelin signaling cascade more broadly than ipamorelin but less aggressively than GHRP-6, resulting in moderate appetite stimulation and cortisol/prolactin elevation that falls between the two.
Research Status
preclinical
Half-Life
~30 minutes
Molecular Formula
C₄₅H₅₅N₉O₆
Primary Use
Growth Hormone
Table of Contents

Benefits

  • One of the most potent GHRPs for acute growth hormone release per dosestrong
  • Moderate appetite stimulation — more than ipamorelin, less than GHRP-6moderate
  • Improved sleep quality through enhanced nocturnal GH pulsatilitymoderate
  • Supports fat metabolism and body composition improvements through GH/IGF-1 elevationmoderate
  • May have cytoprotective effects on gastric mucosa, similar to other GHRPspreliminary

Dosage Protocols

RouteDosage RangeFrequencyNotes
Subcutaneous injection100–300 mcg2–3× daily on an empty stomachStandard dosing protocol. The saturation dose is approximately 100–200 mcg (1–2 mcg/kg). Inject at least 30 minutes before meals.
Subcutaneous injection100 mcg GHRP-2 + 100 mcg CJC-12952–3× dailyGHRH + GHRP synergistic stack. Produces significantly greater GH release than either peptide alone.
Subcutaneous injection200 mcgOnce daily at bedtimeSimplified once-daily protocol targeting the nocturnal GH surge. Lower frequency reduces cumulative cortisol and prolactin exposure.

Medical disclaimer

Dosage information is provided for educational reference only. Always follow your prescriber's instructions and consult a qualified healthcare provider before starting any peptide protocol.

Side Effects

  • Elevated cortisol and prolactin levels (less selective than ipamorelin)common
  • Water retention and mild bloatingcommon
  • Increased appetite (moderate — less intense than GHRP-6)common
  • Transient dizziness or lightheadedness after injectionrare
  • Potential for elevated blood glucose with prolonged use due to GH-mediated insulin resistanceserious

Explore next

Comparisons

Frequently Asked Questions

How does GHRP-2 compare to ipamorelin?
GHRP-2 produces a stronger acute GH release than ipamorelin, but at the cost of also elevating cortisol, prolactin, and appetite. Ipamorelin is uniquely selective — it triggers GH release without significantly affecting other hormones. For most users prioritizing a clean side-effect profile (especially for fat loss or anti-aging), ipamorelin is preferred. GHRP-2 may be chosen when maximum GH output is the primary goal and the user can tolerate or manage the additional hormonal effects.
Does GHRP-2 raise cortisol enough to be a concern?
GHRP-2 does elevate cortisol, though the increase is typically transient and returns to baseline within 1–2 hours. For most healthy individuals using standard doses, this acute cortisol spike is not clinically significant. However, chronic elevated cortisol from multiple daily doses over extended periods could theoretically impair immune function, increase abdominal fat storage, and affect sleep quality. Periodic blood work and limiting cycle duration to 8–12 weeks with breaks can help manage this risk.
Is GHRP-2 better for bulking or cutting?
GHRP-2 is reasonably versatile. For bulking, its moderate appetite stimulation and potent GH release support muscle growth and recovery. For cutting, the GH elevation promotes lipolysis and fat oxidation, but the appetite increase can make maintaining a caloric deficit more difficult. Users focused purely on fat loss generally prefer ipamorelin (no hunger) or CJC-1295 alone. Users seeking a balance of GH output and manageable appetite may find GHRP-2 a good middle ground between GHRP-6 and ipamorelin.
What is the approved medical use of GHRP-2?
GHRP-2, under the name pralmorelin (brand name GHRP Kaken), is approved in Japan as a diagnostic agent for evaluating growth hormone deficiency. A single intravenous dose is administered and GH levels are measured to assess pituitary function. It is not approved for therapeutic use or performance enhancement in any country. All other uses are considered investigational or off-label. This is for informational purposes only.
Can GHRP-2 cause gynecomastia from prolactin elevation?
While GHRP-2 does elevate prolactin, the increase is typically modest and transient. Clinically significant hyperprolactinemia leading to gynecomastia is unlikely at standard doses and cycle lengths. However, individuals who are already prone to elevated prolactin (e.g., from other medications or hormonal conditions) should exercise caution. Monitoring prolactin levels with blood work during use is advisable, especially at higher doses or longer durations.

References

  1. 1
    Dose-dependent GH-releasing effects of GHRP-2 in healthy adult men(1997)PubMed ↗
  2. 2
    GHRP-2 (pralmorelin) as a diagnostic tool for growth hormone deficiency: clinical validation(2001)PubMed ↗
  3. 3
    Growth hormone secretagogue receptor: its structure, signaling, and physiological and pathological roles(2005)PubMed ↗
  4. 4
    Comparative effects of growth hormone secretagogues on GH, cortisol, and prolactin release in humans(2005)PubMed ↗

Last updated: 2026-02-14