Ipamorelin vs GHRP-2 vs GHRP-6 (2026)
Ipamorelin vs GHRP-2 vs GHRP-6: GH release potency, side effects, hunger, cortisol impact, and pricing compared.
The Three Most Popular GHRPs
Growth Hormone Releasing Peptides (GHRPs) stimulate GH release by mimicking ghrelin at the GHSR-1a receptor. Ipamorelin, GHRP-2, and GHRP-6 are the three most studied — each with a distinct balance of potency vs side effects.
For the most potent GHRP of all, see our Hexarelin deep dive.
How GHRPs Work
All three bind the GHSR-1a receptor (ghrelin receptor) in the pituitary gland, triggering a GH pulse. The key differences are in selectivity — how much they activate other pathways beyond GH release.
- More selective = fewer side effects (hunger, cortisol, prolactin)
- Less selective = stronger GH pulse but more off-target effects
Quick Comparison Table
| Feature | Ipamorelin | GHRP-2 | GHRP-6 |
|---|---|---|---|
| GH release potency | Moderate | High | Moderate-High |
| Selectivity | Highest | Moderate | Lowest |
| Hunger stimulation | Minimal | Moderate | Strong |
| Cortisol increase | None | Mild | Moderate |
| Prolactin increase | None | Mild | Mild-Moderate |
| Typical dose | 200–300 mcg | 150–300 mcg | 100–300 mcg |
| Best for | Clean GH pulse, beginners | Maximum GH output | Appetite stimulation + GH |
| Side effect profile | Mildest | Moderate | Most side effects |
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Top Ipamorelin Vendors
Ranked by price, COA availability, and reputation
Detailed Mechanism Comparison
Ipamorelin — The Selective Option
Ipamorelin is the most selective GHRP available. It triggers a clean GH pulse without significantly raising cortisol, prolactin, or appetite.
Key properties:
- Does not increase cortisol — important for avoiding stress hormone elevation
- Does not increase prolactin — no hormonal disruption
- Minimal ghrelin-like hunger — suitable when appetite stimulation is unwanted
- Dose-dependent GH release — predictable, linear response
This selectivity makes Ipamorelin the go-to choice when a clean GH pulse is the primary goal without metabolic side effects.
GHRP-2 — The Potency Pick
GHRP-2 produces the strongest GH release among commonly used GHRPs (excluding Hexarelin, which is even more potent but desensitizes).
Key properties:
- Highest sustained GH output — greater peak amplitude than Ipamorelin
- Mild cortisol elevation — generally considered clinically insignificant at standard doses
- Moderate appetite increase — noticeable but manageable
- No desensitization — unlike Hexarelin, GHRP-2 maintains efficacy with continued use
GHRP-2 is the choice when maximizing GH release is the priority and mild side effects are acceptable.
GHRP-6 — The Appetite Stimulator
GHRP-6 is the original GHRP and the least selective. Its strong ghrelin mimicry produces significant hunger alongside GH release.
Key properties:
- Strong appetite stimulation — the most pronounced of any GHRP (can be a benefit or drawback)
- Moderate cortisol increase — higher than GHRP-2
- Good GH release — effective but not as potent per mcg as GHRP-2
- Strongest ghrelin mimicry — most activation of non-GH ghrelin pathways
GHRP-6 is studied when appetite stimulation is a desired effect (e.g., recovery from illness, muscle gain phases) alongside GH release.
GH Release Comparison
Approximate GH pulse amplitude at standard doses (from published research):
| Peptide | Dose | GH Peak (approximate) |
|---|---|---|
| Ipamorelin | 200 mcg | 20–35 ng/mL |
| GHRP-2 | 200 mcg | 35–60 ng/mL |
| GHRP-6 | 200 mcg | 25–45 ng/mL |
| Hexarelin | 200 mcg | 50–80+ ng/mL |
Note: Individual response varies significantly. These are approximate ranges from research literature.
Stacking with GHRH
All GHRPs work synergistically with GHRH analogs. Combining a GHRP with a GHRH produces a much larger GH pulse than either alone:
- CJC-1295 + Ipamorelin — the most popular combination, clean and predictable
- CJC-1295 DAC + GHRP-2 — sustained baseline elevation + strong pulses
- Sermorelin + Ipamorelin — natural GHRH analog + selective GHRP
For a detailed breakdown of GHRH vs GHRP mechanics, see our GHRH vs GHRP guide.
Dosing Comparison
For research and educational discussion only.
| Peptide | Standard Dose | Frequency | Timing |
|---|---|---|---|
| Ipamorelin | 200–300 mcg | 2–3x daily | Pre-bed, morning, post-workout |
| GHRP-2 | 150–300 mcg | 2–3x daily | Same timing |
| GHRP-6 | 100–300 mcg | 2–3x daily | 30 min before meals (hunger effect) |
Timing Notes
- GH release is blunted by elevated blood sugar — administer on an empty stomach or 2+ hours after eating
- Pre-bed dosing takes advantage of natural nocturnal GH pulse
- Wait 15–30 minutes after injection before eating
Side Effects Comparison
| Side Effect | Ipamorelin | GHRP-2 | GHRP-6 |
|---|---|---|---|
| Hunger | Rare | Moderate | Strong (30–60 min) |
| Water retention | Minimal | Mild | Mild |
| Cortisol | No increase | Small increase | Moderate increase |
| Prolactin | No increase | Small increase | Moderate increase |
| Numbness/tingling | Rare | Occasional | Occasional |
| Desensitization | No | No | No |
The Bottom Line
| If your research goal is... | Best choice |
|---|---|
| Clean GH pulse, minimal sides | Ipamorelin |
| Maximum GH release | GHRP-2 (or Hexarelin short-term) |
| Appetite stimulation + GH | GHRP-6 |
| Beginner-friendly | Ipamorelin |
| Stacking with CJC-1295 | Ipamorelin (most popular combo) |
| Long-term use | Ipamorelin or GHRP-2 (no desensitization) |
| Budget-conscious | Check live pricing above |
For most research contexts, Ipamorelin is the safest starting point due to its selectivity. GHRP-2 is the step up when more GH output is needed. GHRP-6 is best when appetite stimulation is a desired effect.
Related Comparisons & Guides
- Hexarelin: The Strongest GHRP — Deep dive into the most potent GHRP, including desensitization and cardiac effects
- CJC-1295 — The GHRH analog most commonly stacked with Ipamorelin
- CJC-1295 DAC — Extended half-life version for sustained GH elevation
- Sermorelin — Natural GHRH analog, another popular GHRH stacking option
- Tesamorelin — FDA-approved GHRH analog for visceral fat reduction
- Semaglutide vs Tirzepatide — If weight management is also a research goal
- BPC-157 vs TB-500 — The top healing peptides, often explored alongside GH protocols
This article is for educational and research purposes only. It is not medical advice.