The most widely used growth hormone secretagogue stack — combining a GHRH analog (CJC-1295 / Mod GRF 1-29) with a selective GHRP (Ipamorelin) for synergistic pituitary GH release. Available in two CJC variants: no DAC (daily dosing) and with DAC (weekly dosing).
CJC-1295 and Ipamorelin represent the two halves of a growth hormone secretagogue system. CJC-1295 is a modified analog of Growth Hormone Releasing Hormone (GHRH) — the signal that tells the pituitary gland to synthesize and release growth hormone. Ipamorelin is a Growth Hormone Releasing Peptide (GHRP) that amplifies the pituitary's response through the ghrelin receptor pathway.
When administered together, these peptides produce a significantly greater GH pulse than either compound alone. This synergy is well-documented: GHRH primes the pituitary for release, and the GHRP provides the amplification signal. The result is a pulsatile GH secretion pattern that more closely resembles natural physiology than exogenous GH administration.
CJC-1295 comes in two variants that fundamentally change the pharmacokinetic profile. The no-DAC version (also known as Mod GRF 1-29 or Modified Growth Releasing Factor) has a 30-minute half-life and produces short, sharp GH pulses. The with-DAC version includes a Drug Affinity Complex that binds to serum albumin, extending the half-life to approximately 8 days and creating a sustained GH elevation. The choice between variants significantly affects dosing frequency and the character of GH release.
Understanding why CJC-1295 and Ipamorelin work synergistically requires understanding the two distinct signaling pathways that converge at the pituitary gland.
CJC-1295 binds to the GHRH receptor on pituitary somatotroph cells, stimulating both the synthesis and release of growth hormone. It acts as the "primary signal" — telling the pituitary to produce and secrete GH. The no-DAC variant produces a brief, intense signal. The with-DAC variant produces a sustained signal over days.
Ipamorelin is a selective agonist of the growth hormone secretagogue receptor (GHS-R), the same receptor that ghrelin activates. It functions as an "amplifier" — when the pituitary is already being stimulated by GHRH signaling, Ipamorelin dramatically increases the magnitude of the GH pulse. Ipamorelin is considered one of the most selective GHRPs, with minimal effects on cortisol and prolactin compared to older GHRPs like GHRP-6.
The two pathways converge on the same pituitary somatotroph cells but through different receptor systems. Research has demonstrated that combining GHRH and GHRP stimulation produces GH output that exceeds the sum of individual effects — a true pharmacological synergy. This is why the combination protocol is more common than using either peptide alone.
Natural GH secretion occurs in pulses — primarily during deep sleep, with smaller pulses throughout the day. The no-DAC CJC-1295 + Ipamorelin combination mimics this pulsatile pattern, with each injection triggering a discrete GH pulse. CJC-1295 with DAC, by contrast, creates a sustained elevation in GHRH signaling that can alter the natural pulse architecture. This distinction is one of the primary considerations when choosing between variants.
The pharmacokinetic profiles of these three compounds (two CJC variants plus Ipamorelin) differ significantly, which directly informs dosing frequency and timing.
| Parameter | Value | Notes |
|---|---|---|
| Plasma Half-Life | ~30 minutes | Short burst — mimics natural GHRH pulse |
| Dose Range | 100–300 mcg | Per injection, 1-3x daily |
| Time to Peak | ~15 minutes | Rapid absorption and receptor binding |
| GH Pulse Duration | ~2-3 hours | GH release outlasts peptide plasma presence |
| Steady State | N/A | Pulsatile — no true accumulation |
| Parameter | Value | Notes |
|---|---|---|
| Plasma Half-Life | ~192 hours (8 days) | Albumin binding via Drug Affinity Complex |
| Dose Range | 1000–2000 mcg/week | Once or twice weekly injection |
| Time to Peak | ~1-4 hours | Slower absorption due to albumin binding |
| GH Elevation Duration | ~5-8 days | Sustained baseline elevation |
| Steady State | ~3-4 weeks | Based on 8-day half-life accumulation |
| Parameter | Value | Notes |
|---|---|---|
| Plasma Half-Life | ~2 hours | Moderate for a peptide GHRP |
| Dose Range | 100–300 mcg | Per injection, 1-3x daily |
| Time to Peak | ~20 minutes | Rapid SubQ absorption |
| GH Pulse Duration | ~3-4 hours | Triggered GH pulse persists after clearance |
| Selectivity | High | Minimal cortisol/prolactin effects vs. GHRP-6 |
The Drug Affinity Complex (DAC) is a lysine-linked reactive moiety that binds to serum albumin after injection. This albumin binding shields CJC-1295 from enzymatic degradation, extending the half-life from 30 minutes to 8 days — a 384x increase. The trade-off is that the with-DAC variant produces sustained rather than pulsatile GHRH stimulation, which differs from the body's natural release pattern.
Protocol structure depends primarily on whether the no-DAC or with-DAC variant of CJC-1295 is used. Ipamorelin is dosed daily in both cases.
GH secretagogue peptides are sensitive to food timing. Carbohydrates and fats can blunt the GH response. Many protocols observe a 2-hour fast before injection and avoid food for 30 minutes after. Dosing before bed is common to align with the body's natural nocturnal GH surge during deep sleep.
The no-DAC variant (Mod GRF 1-29) produces pulsatile GH release that more closely mimics natural physiology — each injection triggers a discrete burst. The with-DAC variant offers the convenience of weekly dosing but creates sustained GHRH stimulation rather than pulses. Most protocols in common use favor the no-DAC variant paired with daily Ipamorelin.
Both CJC-1295 and Ipamorelin are supplied as lyophilized powders. They can be reconstituted separately or — if supplied as a pre-mixed blend — in a single vial. The process is identical for both peptides.
Gather peptide vials, bacteriostatic water, alcohol swabs, and insulin syringes. Note the vial contents — CJC-1295 and Ipamorelin may be in separate vials or pre-blended (e.g., "CJC/Ipa blend 6mg/6mg" or similar).
Wipe all vial stoppers with alcohol swabs. Allow to air dry.
For individual vials: add 2 mL of bacteriostatic water to a 5 mg CJC-1295 vial (2.5 mg/mL) and 2 mL to a 5 mg Ipamorelin vial (2.5 mg/mL). For blended vials, follow the specific blend ratios — use Milligram's calculator for exact volumes.
Direct bacteriostatic water against the vial wall, not the powder. Allow to dissolve naturally. Do not shake — these are small, fragile peptides. The solution should be clear and colorless.
Draw the required amount from each vial (or from the blended vial). If using separate vials, both peptides can be drawn into the same syringe sequentially for a single injection.
Refrigerate all reconstituted vials at 2-8°C. Use within 3-4 weeks. CJC-1295 no DAC is particularly temperature-sensitive — keep refrigerated immediately after reconstitution.
5 mg CJC-1295 vial + 2 mL water = 2.5 mg/mL (2,500 mcg/mL). For a 200 mcg dose, draw 0.08 mL (8 units on an insulin syringe). Same math applies to Ipamorelin. Use Milligram's reconstitution calculator for any vial size.