GHRP-2 vs Ipamorelin

Overview

GHRP-2 and ipamorelin are both growth hormone releasing peptides (GHRPs) that stimulate GH release via the ghrelin receptor (GHS-R1a). GHRP-2 is considered one of the most potent GHRPs, while ipamorelin is known for its selectivity and cleaner side effect profile. Neither is FDA-approved.

Key Facts

Aspect	GHRP-2	Ipamorelin
Class	GHRP	GHRP
Structure	6 amino acids	5 amino acids
Target	GHS-R1a	GHS-R1a
FDA Status	Not approved	Not approved
Key Feature	High potency	High selectivity

Mechanism Comparison

Aspect	GHRP-2	Ipamorelin
Receptor	GHS-R1a (ghrelin)	GHS-R1a (ghrelin)
GH Release	Strong	Moderate-strong
Cortisol Effect	Increases	Minimal
Prolactin Effect	Increases	Minimal
Appetite Stimulation	Moderate	Minimal

Selectivity Differences

GHRP-2:

• Potent GH release
• Also stimulates cortisol and prolactin
• Moderate appetite increase
• Less selective profile

Ipamorelin:

• Selective GH release
• Minimal cortisol/prolactin elevation
• Minimal appetite effects
• Cleaner side effect profile

GH Release Comparison

Parameter	GHRP-2	Ipamorelin
GH Increase	3-6x baseline	2-4x baseline
Time to Peak	15-30 minutes	15-30 minutes
Duration	2-3 hours	2-3 hours
Dose-response	Steep	More linear

Evidence Comparison

Aspect	GHRP-2	Ipamorelin
Human Studies	Limited	Limited (Phase 2)
Preclinical Data	Moderate	Moderate
Publication Quality	Low-moderate	Low-moderate
Development Status	Abandoned	Abandoned

Research History

GHRP-2:

• Developed as GH secretagogue
• Studied for various indications
• No commercial development pursued

Ipamorelin:

• Developed by Novo Nordisk
• Phase 2 trials for post-operative ileus
• Development discontinued

Side Effect Profile

GHRP-2

Effect	Likelihood	Notes
Cortisol increase	Common	May affect stress axis
Prolactin increase	Common	Potential hormonal effects
Appetite increase	Moderate	Less than GHRP-6
Water retention	Common	GH-related
Flushing	Common	After injection
Numbness/tingling	Occasional	Transient

Ipamorelin

Effect	Likelihood	Notes
Cortisol increase	Minimal	Key advantage
Prolactin increase	Minimal	Key advantage
Appetite increase	Minimal	Unlike other GHRPs
Water retention	Possible	GH-related
Headache	Occasional	Usually mild
Flushing	Occasional	Less than GHRP-2

Comparative Selectivity

Hormone Effect	GHRP-2	Ipamorelin	GHRP-6
GH Stimulation	+++	++	+++
Cortisol	++	+	++
Prolactin	++	+	++
Appetite	++	+	+++

Ipamorelin is notably more selective among GHRPs.

Research Applications

Use	GHRP-2	Ipamorelin
GH Deficiency Research	Studied	Studied
Body Composition	Research	Research
Anti-aging (claimed)	Off-label use	Off-label use
Recovery (claimed)	Anecdotal	Anecdotal

Regulatory Status

Aspect	GHRP-2	Ipamorelin
FDA Approval	No	No
Clinical Development	Abandoned	Abandoned
Availability	Research chemical	Research chemical
WADA Status	Prohibited	Prohibited
Quality Assurance	None (gray market)	None (gray market)

Administration (Research Context)

Aspect	GHRP-2	Ipamorelin
Route	Subcutaneous	Subcutaneous

Combination Considerations

Both GHRPs are sometimes combined with GHRH analogs (sermorelin, CJC-1295) in research:

Combination	Rationale
GHRP + GHRH	Different receptors, potential synergy
Ipamorelin + CJC-1295	Common research combination
GHRP-2 + GHRH analog	Maximize GH pulse

Key Differences

Factor	GHRP-2	Ipamorelin
GH Potency	Higher	Moderate
Selectivity	Lower	Higher
Cortisol Effect	Increases	Minimal
Prolactin Effect	Increases	Minimal
Appetite	Moderate increase	Minimal
Side Effect Profile	More effects	Cleaner

Safety Considerations

Both peptides:

• Lack comprehensive human safety data
• Are not regulated for quality
• Have unknown long-term effects
• Are prohibited in sport
• Should not be used without medical supervision

Summary

• GHRP-2 offers stronger GH release but with cortisol, prolactin, and appetite effects
• Ipamorelin provides more selective GH stimulation with cleaner side effect profile
• Neither is FDA-approved or has robust clinical data
• Ipamorelin’s selectivity is its key advantage
• GHRP-2’s potency comes at cost of less selectivity
• Both are prohibited in sport and available only as research chemicals

---

This comparison is for educational purposes only. Neither peptide is approved for human use. Products sold are unregulated research chemicals with uncertain quality and safety.