GHRP-2 vs Mod-GRF(1-29)
A neutral, side-by-side comparison of two performance & growth hormone peptides — their mechanisms, dosing ranges, administration routes, side effects, and research evidence. For research and educational purposes only.
GHRP-2
GHRP-2 is a synthetic hexapeptide that acts as a ghrelin mimetic, stimulating the pituitary gland to secrete growth hormone (GH). It is one of the most potent GH secretagogues studied, producing stronger GH pulses than GHRP-6 with comparatively less appetite stimulation.
Full profileMod-GRF(1-29)
Mod-GRF(1-29) is a stabilized analog of growth hormone-releasing hormone (GHRH) that spans residues 1–29 of the native peptide. Unlike CJC-1295 (which includes a Drug Affinity Complex for multi-day half-life), Mod-GRF(1-29) has a short ~30-minute active window — mimicking the natural GHRH pulse pattern. It is the preferred GHRH component for precise, pulsatile GH protocols when combined with a GHRP.
Full profile| GHRP-2 | Mod-GRF(1-29) | |
|---|---|---|
| Category | Performance & Growth Hormone | Performance & Growth Hormone |
| Also known as | Growth Hormone Releasing Peptide-2, Pralmorelin, KP 102 | Modified GRF(1-29), CJC-1295 without DAC, Tetrasubstituted GRF, Sermorelin analog |
| Evidence | Preclinical only | Research-stage |
| Dosing range | 100mcg–300mcg mcg, 1–3 times daily, on an empty stomach | 100mcg–200mcg mcg, 2–3x daily, co-administered with a GHRP (pre-sleep, pre-workout, and/or upon waking) |
| Administration | Subcutaneous injection, Intramuscular injection | Subcutaneous injection, Intramuscular injection |
| Key side effects | Increased hunger (less than GHRP-6), Elevated cortisol and prolactin at high doses, Water retention, Injection site irritation | Water retention (mild, dose-dependent), Tingling / numbness in extremities (carpal tunnel-like at high doses), Increased appetite (via GHRP component — less with Mod-GRF alone), Flushing or warmth at injection site |
| Cited sources | 3 references | 2 references |
Key differences
- Evidence level differs: GHRP-2 is preclinical only, while Mod-GRF(1-29) is research-stage.
- Frequency: GHRP-2 is typically 1–3 times daily, on an empty stomach; Mod-GRF(1-29) is 2–3x daily, co-administered with a GHRP (pre-sleep, pre-workout, and/or upon waking).
- Research depth: this profile cites 3 sources for GHRP-2 vs 2 for Mod-GRF(1-29).
How each works
GHRP-2
GHRP-2 has been extensively studied in both animal and human subjects. Clinical trials have demonstrated significant GH elevation in healthy adults, with a peak GH pulse occurring 15–30 minutes post-injection. Studies show it increases IGF-1 levels with chronic use and may have mild cardioprotective properties. Unlike GHRP-6, it has a lower propensity to stimulate cortisol and prolactin at standard doses.
Mod-GRF(1-29)
Native GHRH(1-29) is rapidly cleaved by plasma dipeptidyl peptidase IV (DPP-IV) within 2–3 minutes. Mod-GRF(1-29) incorporates four amino acid substitutions (positions 2, 8, 15, 27) that resist DPP-IV degradation, extending the half-life to approximately 30 minutes while preserving GHRH receptor binding affinity. This creates a half-life window aligned with physiological GH pulsatility, making it suitable for 2–3x daily injections that mimic natural GH release patterns.
This comparison aggregates public research and structured profile data for informational purposes only. It is not medical advice and does not recommend either compound for human use. Consult a qualified healthcare provider before considering any peptide.