Ipamorelin dosage and CJC-1295 stack: the growth hormone research protocol guide
CJC-1295 and Ipamorelin are the most commonly researched growth hormone peptide combination — a pairing of a GHRH analogue and a GHRP that produce synergistically greater GH release than either compound alone because they act through distinct receptor systems converging on the same pituitary somatotrophs. This guide covers the mechanism behind the combination, ipamorelin dosage protocols used in research, how Ipamorelin compares to other GHRPs, timing and administration considerations, and how to use the interactive dose calculator for precise unit calculations.
Ipamorelin dosage — research reference
The following dosing parameters reflect those used in the published research literature and preclinical studies. All values are for educational and research reference only.
| Parameter | Ipamorelin | CJC-1295 No DAC | CJC-1295 With DAC |
|---|---|---|---|
| Research dose range | 200–300 mcg per injection | 1–2 mg per injection | 1–2 mg per injection |
| Frequency | Up to 3x daily (fasted) | 1–2x daily (fasted) | Once weekly |
| Typical schedule | 5 days on / 2 days off | 5 days on / 2 days off | Continuous weekly |
| Administration | Subcutaneous injection | Subcutaneous injection | Subcutaneous injection |
| Timing | Fasted — morning or pre-sleep | Same injection as Ipamorelin | Any time (long half-life) |
| Half-life | ~2 hours | ~30 minutes | ~6–8 days |
| Vial size (typical) | 5mg or 10mg | 5mg or 10mg | 2mg or 5mg |
For precise volume calculations — how many units to draw on a 100-unit insulin syringe for a given dose — use the interactive dose calculator on the dosing guide page. Select your vial size and BAC water volume, enter your target dose in mcg, and the calculator returns exact ml and units. The Ipamorelin and CJC-1295 entries are both listed in the dosing guide.
Why pair a GHRH with a GHRP
Endogenous growth hormone is released in pulses from the pituitary gland, governed by two competing signals: GHRH (which stimulates release) and somatostatin (which inhibits release). GHRH analogues like CJC-1295 amplify the stimulatory signal by binding to the GHRH receptor on pituitary somatotrophs, increasing pulse amplitude. GHRPs like Ipamorelin work through a completely different receptor — the ghrelin/GHS-R1a receptor — to trigger GH release pulses and simultaneously suppress somatostatin, removing the brake on GH release while the GHRH presses the accelerator.
The result of combining both mechanisms is synergistic rather than merely additive: the amplitude of each GH pulse increases (from the GHRH signal) while the frequency of inhibition decreases (from the GHRP's somatostatin suppression). Clinical research has confirmed this synergy — combined GHRH and GHRP administration produces GH release significantly greater than the sum of either compound administered alone at equivalent doses. Alba et al. (1994, J Clin Endocrinol Metab) demonstrated this amplification effect in healthy volunteers, establishing the mechanistic basis for combining these compound classes.
CJC-1295: which form and why it matters
CJC-1295 is a synthetic analogue of GHRH modified to resist enzymatic degradation in plasma. It is available in two forms with meaningfully different pharmacokinetic profiles. CJC-1295 without DAC (Drug Affinity Complex) has a half-life of approximately 30 minutes and produces short-acting, pulsatile GH release that closely mimics the natural GH secretion pattern. CJC-1295 with DAC has a half-life of approximately 6–8 days due to covalent binding to albumin via a maleimide linker, producing sustained GH elevation that diverges from the natural pulsatile pattern.
For the CJC-1295/Ipamorelin stack, CJC-1295 No DAC is most commonly used in research protocols because its short pulsatile release pattern synchronises with Ipamorelin's GHRP-mediated GH pulses. The two compounds are typically administered in the same injection for convenience. CJC-1295 With DAC is used in protocols where simplified, infrequent dosing is the priority — once-weekly administration covers the full week without daily injections. See the CJC-1295 research profile for full pharmacokinetic details.
Ipamorelin vs GHRP-2 vs GHRP-6 — choosing the right GHRP
Ipamorelin is one of three GHRPs most commonly used in research protocols. All three bind the ghrelin/GHS-R1a receptor and stimulate GH release, but they differ meaningfully in their selectivity — specifically in whether they also stimulate cortisol, prolactin, and appetite-related hormones. This is the most important distinction for researchers choosing between them.
| GHRP | GH release | Cortisol effect | Prolactin effect | Appetite/ghrelin effect | Research preference |
|---|---|---|---|---|---|
| Ipamorelin | Strong | Minimal | Minimal | Minimal | Clean GH stimulation without side hormone effects |
| GHRP-2 | Strong | Moderate ↑ | Moderate ↑ | Moderate | Maximum GH pulse amplitude; body composition focus |
| GHRP-6 | Moderate–strong | Moderate ↑ | Moderate ↑ | Strong ↑ (hunger) | Appetite stimulation as a research variable; older compound class |
Ipamorelin's selectivity makes it the preferred GHRP for combination protocols where clean GH stimulation is the objective and minimising cortisol or prolactin elevation is a research priority. GHRP-2 produces a stronger GH pulse amplitude but at the cost of moderate cortisol and prolactin co-stimulation. GHRP-6 stimulates significant hunger through ghrelin receptor activation — an effect that is itself a useful research variable in appetite and feeding studies, but an unwanted side effect in body composition protocols. See the dosing guide for GHRP-2 and GHRP-6 dose calculators.
Timing and fasting protocols
Fasted administration is critical for GH peptide stacks. Carbohydrate and fat intake both stimulate insulin release, and elevated insulin suppresses GH release — blunting the effect of both the GHRH and GHRP signals. Standard research protocols administer GH stacks either first thing in the morning (at least 30–45 minutes before eating) or immediately before sleep (at least 2–3 hours after the last meal). Pre-sleep administration aligns with the body's largest natural GH pulse, which occurs within the first 90 minutes of deep sleep, and the GHRH/GHRP combination amplifies this natural pulse rather than replacing it.
The 5 days on / 2 days off schedule is used to maintain pituitary receptor sensitivity and prevent downregulation of the GHRH and ghrelin receptors with chronic daily stimulation. Continuous daily use without rest periods is associated with receptor desensitisation and diminishing GH pulse amplitude over time in animal models. The rest period allows receptor recovery and maintains the potency of subsequent dosing cycles.
Pre-formulated blends and the 2X combination
The Peptide Hub database includes several pre-formulated growth hormone blend options. The 2X Tesamorelin/Ipamorelin blend substitutes Tesamorelin — an FDA-approved GHRH analogue for HIV-associated lipodystrophy — for CJC-1295, offering a GHRH component with a stronger human clinical evidence base. The 3X and 4X blends add MGF and GHRP-2 for broader muscle repair and body composition research protocols. For researchers who prefer working with individual compounds at precisely controlled doses, separate Ipamorelin and CJC-1295 vials from the database allow independent titration of each component. See the full blend lineup in the peptide database.
Editorial Note: This article is published for research and educational purposes only. Peptide Hub does not sell peptides, receive commissions from peptide vendors, or endorse any specific supplier. All compounds discussed are research peptides not approved for human therapeutic use except where specifically noted. Tesamorelin is FDA-approved for HIV-associated lipodystrophy only. This is not medical advice.
Sources
- Alba M, et al. (1994). Both growth hormone (GH)-releasing peptide-2 and GH-releasing hormone amplify pulsatile GH secretion in healthy individuals. J Clin Endocrinol Metab. PubMed
- Kojima M, et al. (1999). Ghrelin is a growth-hormone-releasing acylated peptide from stomach. Nature. PubMed
- Bowers CY, et al. (1984). On the in vitro and in vivo activity of a new synthetic hexapeptide that acts on the pituitary to specifically release growth hormone. Endocrinology. PubMed