GHRP-2 vs GHRP-6
GHRP-2 and GHRP-6 are both growth hormone releasing peptides that stimulate GH secretion through the ghrelin receptor (GHS-R), but they differ in potency, selectivity, and secondary effects. GHRP-2 is considered the more potent and selective of the two, producing higher GH output per microgram with less appetite stimulation. GHRP-6 is the older, more thoroughly studied compound with pronounced appetite-stimulating effects that mirror its closer mimicry of ghrelin signaling.
TL;DR — The Verdict
GHRP-2 produces more GH per dose with fewer appetite-related side effects, making it better for research focused purely on GH output. GHRP-6 is the choice when appetite stimulation is desired alongside GH release, or when cost is a primary consideration. Both have been largely superseded by Ipamorelin for protocols prioritizing minimal side effects.
At a Glance
GHRP-2
Full profile →The potent, selective growth hormone releasing peptide
Strengths
- + Strongest GH release among GHRPs per dose
- + Less appetite stimulation than GHRP-6
- + More selective GH release profile
- + Well-characterized in clinical studies
- + Good for research where hunger is a confound
Limitations
- − Can elevate cortisol and prolactin at higher doses
- − More expensive than GHRP-6 typically
- − Less appetite-stimulating (disadvantage for underweight research)
- − Can disrupt sleep if dosed late
GHRP-6
Full profile →The hunger-inducing growth hormone secretagogue
Strengths
- + Strong GH release with substantial appetite stimulation
- + Most studied GHRP variant in literature
- + Significant ghrelin-like appetite effects
- + Lower cost per dose typically
- + Good for research requiring caloric intake increase
Limitations
- − Significant hunger increase can be undesirable
- − Elevates cortisol and prolactin more than Ipamorelin
- − Water retention more common
- − Less selective than newer GHRPs
Detailed Comparison
GH Release Potency
GHRP-2 winsGHRP-2
GHRP-2 consistently shows the highest GH release among the GHRP family in comparative studies. At standard doses of 100-300 mcg subcutaneously, it produces GH peaks 5-15x above baseline. The dose-response curve is relatively linear up to saturation. Clinical pharmacology studies confirm it is approximately 20-30% more potent than GHRP-6 at equivalent doses for raw GH output.
GHRP-6
GHRP-6 produces substantial GH release, typically 3-10x above baseline at standard doses. While slightly less potent than GHRP-2 on a per-microgram basis, the GH output is still clinically significant. GHRP-6 was actually the first compound in the GHRP series to be extensively studied and established the benchmark that later GHRPs were compared against.
Bottom line: GHRP-2 releases approximately 20-30% more GH per equivalent dose. Both are effective, but GHRP-2 is more potent.
Appetite Effects
TieGHRP-2
GHRP-2 produces mild to moderate appetite stimulation, noticeably less than GHRP-6. While it does activate the ghrelin receptor, its binding profile produces less intense hunger signaling. For research where appetite is a confounding variable or where subjects are trying to maintain caloric control, GHRP-2 is the preferred choice among GHRPs (though Ipamorelin is even cleaner).
GHRP-6
GHRP-6 is known for intense appetite stimulation, often described as ravenous hunger beginning 20-30 minutes post-injection and lasting 30-60 minutes. This effect is so pronounced it has been studied as a potential treatment for cachexia and appetite loss. The ghrelin-mimetic activity drives this hunger through hypothalamic appetite centers. For research into appetite stimulation, this is a feature; for body composition research, it can be a complication.
Bottom line: Neither wins; it depends on goals. GHRP-6 is better when appetite increase is desired. GHRP-2 is better when hunger is unwanted. Different tools for different protocols.
Hormonal Side Effects
GHRP-2 winsGHRP-2
GHRP-2 elevates cortisol and prolactin at higher doses, though less dramatically than GHRP-6. At standard research doses (100-200 mcg), these elevations are typically modest and transient. At doses above 300 mcg, cortisol increases become more meaningful. This is why many protocols cap GHRP-2 doses at the saturation point rather than continuing to escalate.
GHRP-6
GHRP-6 shows greater elevation of cortisol and prolactin compared to GHRP-2 at equivalent doses. The cortisol increase is particularly notable and can be a concern in stress-related research or protocols involving cortisol-sensitive outcomes. Prolactin elevation is also more pronounced, which can be relevant for reproductive or hormone-sensitive research designs.
Bottom line: GHRP-2 produces fewer hormonal side effects at equivalent doses. Both elevate cortisol/prolactin more than Ipamorelin, which is essentially clean.
Research Validation
GHRP-6 winsGHRP-2
GHRP-2 has solid research backing with numerous clinical pharmacology studies characterizing its GH-releasing properties, dose-response relationships, and safety profile. It has been evaluated in both healthy volunteers and various clinical populations. The research base is strong though slightly smaller than GHRP-6 due to being developed later.
GHRP-6
GHRP-6 has the longest research track record of any GHRP, with studies dating back to the 1980s. It is the most extensively published GHRP in peer-reviewed literature and has been used as a standard GH provocation test in endocrinology. This depth of research provides strong reference data for comparison. Many fundamental GHRP pharmacology concepts were established using GHRP-6.
Bottom line: GHRP-6 has a longer and deeper research history. GHRP-2 is well-validated but with a smaller total body of published work.
Who Should Choose What?
Choose GHRP-2 if:
- → Research prioritizing maximum GH output per dose
- → Protocols where appetite stimulation is undesirable
- → Studies sensitive to cortisol/prolactin confounders
- → Body composition research where caloric control matters
- → Stacking with CJC-1295 for combined GH protocols
Choose GHRP-6 if:
- → Research specifically studying appetite stimulation
- → Cachexia or appetite loss intervention studies
- → Budget-sensitive protocols (typically lower cost)
- → Studies requiring extensive published reference data
- → Protocols where increased caloric intake is beneficial
Ready to Calculate Your Protocol?
Use our dosing and reconstitution calculators pre-loaded with GHRP-2 or GHRP-6 values.
Research & Educational Use Only
All content is for informational and research purposes only. This site does not provide medical advice, diagnosis, or treatment. Consult a qualified healthcare professional before using any peptide or supplement.
The information presented here is compiled from published research studies and is intended for informational purposes only. Individual results may vary. Always consult with a licensed healthcare provider.