CJC-1295 / Ipamorelin Stack 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.
CJC-1295 / Ipamorelin Stack
The CJC-1295 (without DAC) and Ipamorelin combination is the most widely researched and community-validated growth hormone secretagogue stack. By pairing a GHRH analog with a selective GHRP, the two peptides act synergistically — producing GH pulses significantly larger than either compound alone, while maintaining a physiological pulse pattern and minimal side effects.
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| CJC-1295 / Ipamorelin Stack | Mod-GRF(1-29) | |
|---|---|---|
| Category | Performance & Growth Hormone | Performance & Growth Hormone |
| Also known as | CJC-1295 Ipamorelin, Mod GRF 1-29 Ipamorelin, CJC Ipa stack, CJC-1295 without DAC with Ipamorelin, GHRH GHRP combination | Modified GRF(1-29), CJC-1295 without DAC, Tetrasubstituted GRF, Sermorelin analog |
| Evidence | FDA-approved | Research-stage |
| Dosing range | 100mcg each–300mcg each mcg, once daily before sleep (or 2–3x daily for more aggressive protocols) | 100mcg–200mcg mcg, 2–3x daily, co-administered with a GHRP (pre-sleep, pre-workout, and/or upon waking) |
| Administration | Subcutaneous injection (both compounds), Administered together in the same injection | Subcutaneous injection, Intramuscular injection |
| Key side effects | Water retention (mild, common), Tingling or numbness in hands/feet (transient), Headache (usually first 1–2 weeks), Fatigue or increased sleepiness (often desired at night dose) | 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 | 2 references | 2 references |
Key differences
- Evidence level differs: CJC-1295 / Ipamorelin Stack is fda-approved, while Mod-GRF(1-29) is research-stage.
- Administration: CJC-1295 / Ipamorelin Stack — Subcutaneous injection (both compounds), Administered together in the same injection; Mod-GRF(1-29) — Subcutaneous injection, Intramuscular injection.
- Frequency: CJC-1295 / Ipamorelin Stack is typically once daily before sleep (or 2–3x daily for more aggressive protocols); Mod-GRF(1-29) is 2–3x daily, co-administered with a GHRP (pre-sleep, pre-workout, and/or upon waking).
How each works
CJC-1295 / Ipamorelin Stack
CJC-1295 without DAC (Mod GRF 1-29) stimulates GHRH receptors on the pituitary, increasing the amplitude of GH pulses. Ipamorelin independently triggers GH release via the ghrelin receptor (GHS-R1a) with high selectivity — minimal cortisol, prolactin, or aldosterone co-elevation. The combination exploits two separate receptor pathways to produce synergistic GH output. Animal and human studies on each compound individually confirm GH and IGF-1 elevation. The combination is extrapolated from mechanistic research and is the most studied protocol in the peptide research community.
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.