CalcMyPeptide
Growth HormoneAlso known as: Growth Hormone Releasing Peptide 2

GHRP-2

GHRP-2 (Pralmorelin) operates as the distinct middle ground in the secretagogue hierarchy—it is aggressively more potent at inducing total Growth Hormone release than GHRP-6, yet it triggers substantially less hunger and gastric motility. Extensively utilized in both pediatric GH deficiency studies and extreme anabolism protocols, GHRP-2 offers a colossal GH spike ideal for maximizing IGF-1 conversion, though its power comes with an observable, transient increase in secondary stress hormones.

Reviewed by CalcMyPeptide Editorial Team
Last updated: April 2026Evidence: Moderate1 peer-reviewed citation

Quick Stats

Half-Life~15-60 minutes
Dose Range100-300 mcg/injection
Frequency2-3× daily
Vial Sizes5 mg
Bioavailability~100% (subcutaneous)
Year Developed1993

Scientific Data

Molecular Formula
C45H55N9O6
Molecular Weight
817.99 g/mol
CAS Number
PubChem ID

Mechanism of Action

GHRP-2 is a synthetic hexapeptide and second-generation growth hormone releasing peptide. It is the most potent of the GHRP family for GH release. Like GHRP-6, it activates the ghrelin receptor (GHS-R1a), but with a higher binding affinity. GHRP-2 produces stronger GH pulses than GHRP-6 with a moderately lower appetite stimulation effect (though still greater than Ipamorelin).

GHRP-2 also elevates cortisol and prolactin more than Ipamorelin but less than Hexarelin. It does not exhibit desensitization at standard doses over typical cycle lengths.

Source: PMID: 9003422

Background & History

GHRP-2 (Pralmorelin) is the most potent stimulator of the GHRP family. It was extensively studied as a diagnostic tool for GH deficiency and reached clinical trial stage in Japan (Kaken Pharmaceutical) in the early 2000s. Its higher binding affinity for GHS-R1a versus GHRP-6 translates to 20–30% greater peak GH release. The moderate appetite stimulation (lower than GHRP-6) and stronger GH output make it popular for performance-focused protocols.

Research Use Cases

  • Maximum GH pulse output for performance and anabolic goals
  • GH deficiency testing (clinical diagnostic use)
  • Body composition optimization with moderate appetite increase
  • Recovery protocols requiring aggressive GH stimulation

Dosing Protocol

Typical Dose100-300 mcg/injection
Frequency2-3× daily
Half-Life15-60 minutes
Common Vial Sizes5 mg

Dosing Protocols

Standard Protocol

Dose
100 - 300 mcg
Frequency
2-3× daily
Note: Inject fasted. Moderate appetite stimulation. Pre-bed and waking doses are most popular.

Body-Weight Dosing Reference

Estimated doses extrapolated from the published research range of 100300 mcg/day (referenced to 70 kg / 154 lb). These are approximations — consult a qualified healthcare provider for personalised guidance.

WeightLowTargetHigh
120 lb(54 kg)77 mcg154 mcg231 mcg
140 lb(63 kg)90 mcg180 mcg270 mcg
160 lb(73 kg)104 mcg209 mcg313 mcg
180 lb(82 kg)117 mcg234 mcg351 mcg
200 lb(91 kg)130 mcg260 mcg390 mcg
220 lb(100 kg)143 mcg286 mcg429 mcg
250 lb(113 kg)161 mcg323 mcg484 mcg

💉 For exact syringe units based on your vial concentration, use the GHRP-2 Reconstitution Calculator →

Administration

Route
Subcutaneous injection
Timing
Must inject fasted. Similar timing to GHRP-6 but with less appetite impact.
Fasting Required?
Yes — inject on an empty stomach

Expected Timeline

Week 1-2
GH pulse noticeably stronger vs GHRP-6. Sleep depth improves.
Month 1-2
Lean mass preservation, fat reduction, and improved recovery.

Who Is It For?

GH Optimization (Max Output)

High

Most potent GHRP by raw GH release. Best for users who want maximum secretagogue effect.

Body Recomposition

Moderate

Strong GH pulse with moderate appetite effect — middle ground between GHRP-6 and Ipamorelin.

Reconstitution Example

Vial
5 mg
Water
2.5 mL
Concentration
2 mg/mL
Per Unit (100u syringe)
20 mcg
Dose of 100 mcg = 5 units on a 100-unit insulin syringe

Safety & Considerations

Research peptide. Moderately stimulates appetite, cortisol, and prolactin. Less appetite stimulation than GHRP-6 but more than Ipamorelin. Use on an empty stomach for optimal GH pulse.

Regulatory & Legal Status

FDA Status (US)
Research Only
WADA Status (2026)
Prohibited (S2)

Competitive athletes subject to anti-doping controls should not use GHRP-2.

Classification

Research Chemical

US Compounding: Not eligible / not available

⚠️ This information is for educational purposes only and may not reflect the most current regulatory updates. Always verify with official FDA, WADA, and jurisdiction-specific sources before use.

Interactions & Contraindications

Greater cortisol elevation than Ipamorelin — not ideal for chronic stress or adrenal fatigue contexts. Prolactin elevation may affect libido/sexual function in some users. Empty stomach required for effective dosing.

Synergies & Common Stacks

+ CJC-1295 no DAC

Most potent GHRH+GHRP stack for raw GH output. Best for anabolic or aggressive recovery protocols where cortisol elevation is acceptable.

Dosing Quick Reference

GHRP-2— Dosing Guide
Dose Range
100-300 mcg/injection
Half-Life
15-60 minutes
Frequency
2-3× daily
Route
Subcutaneous
5 mg vial
💧 2.5 mL BAC water📐 2 mg/mL concentration💉 20 mcg/unit (100u syringe)
Growth Hormonecalcmypeptide.com

Frequently Asked Questions

Is GHRP-2 stronger than GHRP-6?
Yes — GHRP-2 produces a stronger GH release than GHRP-6 with somewhat less appetite stimulation. It is the most potent GHRP by GH output.
What is the GHRP-2 dosing protocol?
100-300 mcg per injection, 2-3 times daily on an empty stomach. Best combined with a GHRH analog (CJC-1295 no DAC) for maximum synergy.

References

  1. Bowers CY "Growth hormone-releasing peptides".” Journal of Pediatric Endocrinology & Metabolism (1993). PMID: 8186715

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