CJC-1295 / Ipamorelin Stack vs MK-677 (Ibutamoren)
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 profileMK-677 (Ibutamoren)
Oral non-peptide growth hormone secretagogue that mimics ghrelin to stimulate GH and IGF-1 release without injection. Long half-life (~24 hours) enables once-daily oral dosing. Widely researched for body composition, sleep quality, and IGF-1 elevation.
Full profile| CJC-1295 / Ipamorelin Stack | MK-677 (Ibutamoren) | |
|---|---|---|
| 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 | Ibutamoren, Nutrobal, MK677, L-163,191 |
| Evidence | FDA-approved | Research-stage |
| Dosing range | 100mcg each–300mcg each mcg, once daily before sleep (or 2–3x daily for more aggressive protocols) | 10mg–50mg mg, once daily oral |
| Administration | Subcutaneous injection (both compounds), Administered together in the same injection | Oral (capsule/liquid) |
| 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, Increased appetite, Elevated fasting glucose (long-term), Fatigue (initial, transient) |
| Cited sources | 2 references | 2 references |
Key differences
- Evidence level differs: CJC-1295 / Ipamorelin Stack is fda-approved, while MK-677 (Ibutamoren) is research-stage.
- Administration: CJC-1295 / Ipamorelin Stack — Subcutaneous injection (both compounds), Administered together in the same injection; MK-677 (Ibutamoren) — Oral (capsule/liquid).
- Dosing units differ: CJC-1295 / Ipamorelin Stack is dosed in mcg, MK-677 (Ibutamoren) in mg — they operate at different scales.
- Frequency: CJC-1295 / Ipamorelin Stack is typically once daily before sleep (or 2–3x daily for more aggressive protocols); MK-677 (Ibutamoren) is once daily oral.
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.
MK-677 (Ibutamoren)
MK-677 binds the ghrelin receptor (GHS-R1a) to stimulate pulsatile GH release and increase circulating IGF-1. Unlike peptide GHRPs it survives oral administration. Clinical trials demonstrate significant increases in GH pulsatility and IGF-1 without suppression of the endogenous GH axis, though long-term use raises glucose metabolism concerns.
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.