Two different receptors, two different mechanisms, and one of the most synergistic combinations in peptide protocols. Here is how each works on its own — and why most people end up running both.
A GHRH analogue that binds to the growth hormone releasing hormone receptor in the pituitary. It amplifies existing GH pulses — think of it as turning up the volume on a signal that is already there. The no-DAC version has a short half-life (~30 minutes) and is designed to be co-administered with a GHRP like Ipamorelin. The DAC version lasts ~8 days and can be dosed weekly, but at the cost of a less pulsatile GH release pattern.
A GHRP that mimics ghrelin and binds to ghrelin receptors in the pituitary, triggering GH pulses. It is the most selective GHRP available — it produces far less cortisol, prolactin, and hunger stimulation than GHRP-6 or GHRP-2, making it the go-to choice for most protocols. Half-life of ~2 hours means it needs to be dosed 2–3 times daily for sustained effect, typically before bed and/or fasted in the morning.
Key insight
CJC-1295 and Ipamorelin work on different receptors (GHRH vs ghrelin). This means they do not compete — they cooperate. Research shows combined GHRH + GHRP administration produces GH release approximately 10× greater than either peptide alone. The stack is not just additive; it is genuinely synergistic.
| CJC-1295 | Ipamorelin | |
|---|---|---|
| Class | GHRH analogue | GHRP / selective ghrelin mimetic |
| Mechanism | Binds GHRH receptors in the pituitary → stimulates GH secretion | Binds ghrelin receptors in the pituitary → stimulates GH pulse |
| Half-life | ~30 min (no DAC) / ~8 days (with DAC) | ~2 hours |
| Typical dose | 100–200 mcg/injection (no DAC) / 1–2 mg/week (DAC) | 200–300 mcg/injection |
| Frequency | Per injection (no DAC) / once weekly (DAC) | 2–3× daily |
| GH pulse pattern | Amplifies existing GH pulses (does not trigger independently) | Triggers discrete GH pulses |
| Cortisol/prolactin | Minimal increase | Minimal increase (more selective than GHRP-6/2) |
| Hunger increase | None | Mild (lower than GHRP-6) |
| Best stacked with | Ipamorelin (no DAC) or another GHRP | CJC-1295 (no DAC) or another GHRH analogue |
| Timing | Same injection as Ipamorelin when using no DAC | Before sleep or fasted — avoid post-meal |
The DAC (Drug Affinity Complex) modification allows CJC-1295 to bind to albumin in the blood, extending its half-life from ~30 minutes to approximately 8 days. This allows weekly dosing, which is convenient — but it comes with a trade-off. Continuous GHRH stimulation over 8 days creates a sustained, blunted GH environment rather than the sharp, natural GH pulses the body normally produces. Over time, this may reduce the pituitary's sensitivity to GHRH stimulation.
CJC-1295 without DAC (sometimes listed as Modified GRF 1-29 or Mod GRF 1-29) has a short half-life and must be dosed at each injection alongside Ipamorelin. The pulsatile pattern this creates more closely mirrors natural GH physiology. Most experienced users and researchers prefer the no-DAC version for this reason, despite the more frequent injections.
GHRP-6 and GHRP-2 are older GHRPs that also work at the ghrelin receptor. They produce meaningful GH release but with significant side effects: GHRP-6 causes pronounced hunger (enough to interfere with diet); GHRP-2 causes substantial cortisol and prolactin elevation; both can cause significant water retention. Ipamorelin is highly selective — it triggers GH release with minimal cortisol, minimal prolactin, and only mild hunger increase. For most protocols, Ipamorelin offers the best ratio of GH stimulation to unwanted side effects.
CJC-1295 (no DAC) + Ipamorelin — common protocol
If budget or access limits you to one peptide: Ipamorelin alone produces meaningful GH pulses and is the more versatile standalone option. CJC-1295 alone amplifies existing GH signalling but cannot trigger new pulses independently — you need a GHRP alongside it for a significant effect. That said, most protocols quickly evolve to the full stack once the synergy becomes apparent.
CJC-1295 is a synthetic analogue of growth hormone releasing hormone (GHRH). It binds to GHRH receptors in the pituitary gland and amplifies the body's own GH pulses. It comes in two versions: without DAC (Drug Affinity Complex), which has a short half-life of ~30 minutes, and with DAC, which extends the half-life to approximately 8 days. The no-DAC version is almost always used in combination with Ipamorelin and dosed at the time of injection.
Ipamorelin is a growth hormone releasing peptide (GHRP) and selective ghrelin receptor agonist. It triggers discrete GH pulses from the pituitary by mimicking ghrelin. It is considered the most selective GHRP — it causes minimal cortisol, prolactin, or ACTH release compared to GHRP-6 or GHRP-2, and produces less hunger stimulation. Half-life is approximately 2 hours.
They work on different receptors but have a synergistic effect on GH release. CJC-1295 (GHRH) amplifies GH pulse amplitude; Ipamorelin (GHRP) triggers GH pulse frequency. Using both together produces a significantly greater GH release than either alone — studies show a 10-fold increase in GH with combined GHRH + GHRP administration versus either peptide alone. The combination also mimics the body's natural two-signal GH secretion pattern more accurately.
CJC-1295 without DAC (also called Mod GRF 1-29) has a short half-life and is designed to be used alongside Ipamorelin at each injection. It produces a more natural, pulsatile GH release pattern. CJC-1295 with DAC binds to albumin in the blood and extends its half-life to ~8 days, allowing once-weekly dosing. However, the sustained elevation of GHRH signalling may blunt the pulsatile nature of GH release over time. Most experienced users prefer no DAC for its more physiological effect.
The most common timing is before sleep, injected together in the same subcutaneous injection. GH is naturally secreted in largest amounts during deep sleep, and dosing before bed takes advantage of this window. The second most common timing is first thing in the morning in a fasted state. Avoid injecting within 1–2 hours of a carbohydrate-heavy meal, as elevated insulin suppresses GH release.
The most commonly reported effects over a 3–6 month protocol are: improved sleep quality (often within the first 2 weeks), improved recovery from training, increased lean muscle over time, reduced body fat (particularly visceral), improved skin quality, and better joint function. The effects are gradual — this is not a rapid-acting protocol like anabolic steroids. Most users notice meaningful changes after 8–12 weeks.
Common and generally mild side effects include water retention (especially early in the protocol), tingling or numbness in the hands, and mild hunger increase from Ipamorelin. Some users experience temporary fatigue or lethargy, particularly when starting. Because Ipamorelin is highly selective, the cortisol and prolactin increases that occur with older GHRPs (GHRP-6, GHRP-2) are minimal.
Log CJC-1295 and Ipamorelin injections separately with dose, site, and timing. Set reminders for your daily protocol and track body composition changes over your cycle.
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