CJC-1295 + ipa is the GH peptide stack people actually run. Two compounds, two receptors, one pulse, that's the whole point. CJC-1295 hits the GHRH receptor and tells the pituitary to load up. Ipamorelin hits the ghrelin receptor (GHS-R1a) and pulls the trigger. Run them together and the pulse is bigger than either alone. Below: what each one does, why people stack them, what the human data actually says, and how protocols look in practice.
Key Takeaways
- —CJC-1295 DAC has a half-life of 6–8 days; a single pin raises plasma GH 2–10x and IGF-1 0.5–3x for 9–11 days (PubMed, Teichman et al., 2006).
- —Ipamorelin is the first GH secretagogue shown to release GH cleanly, even at 200x its effective dose, ACTH and cortisol didn't budge (PubMed, Raun et al., 1998).
- —The stack works on dual receptors: GHRH-R (CJC-1295) plus ghrelin-R/GHS-R1a (ipa) — bigger pulse than either alone.
- —Both are FDA Category 2 (2024). Can't be commercially compounded in the US.
- —Long-term human data past 6–12 months is basically not there yet.
CJC-1295 is a synthetic GHRH analogue, the hypothalamic signal that tells the pituitary to dump GH. Native GHRH lasts a few minutes in plasma before DPP-IV chops it up. CJC-1295 swaps in amino acids that resist that enzyme, so the signal sticks around long enough to actually do something.
Two versions exist, and the difference matters a lot in practice:
CJC-1295 no-DAC (also called Mod GRF 1-29): Half-life around 30 minutes. Sharp, physiological GH pulse when you pin it, basically mimics the natural rhythm. Run it 1–2x daily.
CJC-1295 DAC (Drug Affinity Complex): The DAC tag binds the peptide covalently to albumin in the blood, stretching the half-life to 6–8 days. One pin of CJC-1295 DAC raises plasma GH 2–10x over baseline for 6+ days and pushes IGF-1 up 0.5–3x for 9–11 days (Teichman et al., JCEM, 2006). That's still the only peer-reviewed human PK study on CJC-1295 DAC, which tells you something about the state of the field.
The DAC vs no-DAC choice has real protocol consequences. Weekly DAC pins are convenient but produce flat, non-pulsatile GH. Daily no-DAC pins are more annoying but keep the rhythm of natural GH secretion, which probably matters for avoiding pituitary receptor desensitisation.
Ipamorelin is a pentapeptide GH secretagogue, basically a clean ghrelin mimic. It binds GHS-R1a in the pituitary and hypothalamus and triggers a GH pulse. Older GHRPs (GHRP-2, GHRP-6) do the same job but drag cortisol, ACTH, and prolactin along for the ride. Ipa doesn't.
In the 1998 Raun et al. characterisation paper in Endocrinology, ipa was tested at doses 200x its effective dose for GH release (ED50). Even there, ACTH and cortisol didn't differ significantly from GHRH alone (PubMed, 1998). GHRP-2 and GHRP-6 in the same paradigm bumped both, which is exactly why most clinical stacks moved to ipa.
Ipa also doesn't push prolactin meaningfully or trigger the appetite spike you get from real ghrelin. That selectivity, GH release without the off-target hormone cascade, is why ipa became the default GHRP for stacking.
Ipa's half-life is around 2 hours. You get a short, sharp GH pulse that fades over 3–4 hours. Pair it with a GHRH analogue like CJC-1295 and the combined pulse is bigger and longer than either compound on its own.
The pituitary releases GH when two inputs hit at the same time:
CJC-1295 hits the first receptor. Ipa hits the second. Activate both at once and the GH pulse is synergistic, more than the sum of either input alone. That's the whole pharmacological case for the stack.
According to the 2006 phase II study by Teichman et al. in the Journal of Clinical Endocrinology & Metabolism, multiple CJC-1295 injections produced dose-dependent increases in plasma GH concentrations, with mean GH concentrations increasing by 1.5 to 3.0 fold during 28 days after dosing, and mean IGF-1 concentrations increasing by 1.3 to 1.5 fold (PubMed).
The clinical goal isn't supraphysiological GH. It's restoring the secretion pattern of younger physiology, lifting chronically low GH output back toward what a healthy 25–35 year old runs naturally.
The human evidence base is thin but not empty.
CJC-1295 DAC pharmacokinetics (Teichman et al., 2006): The only formal phase I/II human study. 65 healthy adults received single or multiple doses of CJC-1295 DAC. Dose-dependent GH and IGF-1 elevation, decent safety profile. Still the primary human PK reference for the compound.
Older adults and body composition (2025 study): A 2025 study in older adults running combined CJC-1295 / ipa showed meaningful gains in lean mass, strength, and physical performance, attributed to better GH output and improved protein synthesis. Sample sizes were small and the study design varied by site, so it's promising but not RCT-grade.
FDA Category 2 submissions (2024): In December 2024 the FDA published submissions on both CJC-1295 and ipa for the 503A bulk compounding list. Both were denied Category 1 (safe to compound) status on insufficient human safety and efficacy data at the proposed doses. That doesn't mean they're dangerous, it means the data isn't there yet for the FDA to greenlight commercial compounding.
These reflect clinical practice patterns and extrapolation from preclinical and limited human data, not FDA-approved indications.
| Protocol | CJC-1295 Dose | Ipamorelin Dose | Frequency |
|---|---|---|---|
| Conservative | 100 mcg (no-DAC) | 200 mcg | Daily pre-bed |
| Standard | 200 mcg (no-DAC) | 300 mcg | Twice daily |
| Convenience (DAC) | 1–2 mg (with DAC) | 200–300 mcg | Weekly + daily |
IGF-1 is the main surrogate for GH-axis activity. Pull a baseline before you start, retest at 6–8 weeks. The target in clinical GH optimisation is the upper quartile of the age-adjusted normal range, not supraphysiological.
If IGF-1 climbs too high, drop the dose. Sustained supraphysiological IGF-1 is linked to increased cell proliferation rates and theoretical cancer risk, the same concern that applies to exogenous rhGH at pharmacological doses.
Other things worth watching: fasting glucose (GH is counter-regulatory to insulin, so BG creep is a real thing on cycle), thyroid function (GH influences T4→T3 conversion), and cortisol (more relevant with dirty GHRPs, less of an issue with clean ipa). Numb hands or wrist tingling on cycle is the carpal tunnel signal from too much GH and means it's time to back the dose down. Mild water retention in the first couple weeks is common and usually settles.
Neither compound is FDA-approved for any therapeutic use. Both are Category 2 bulk drug substances as of 2024. They're not controlled substances, but they can't be legally compounded commercially. WADA bans both in sport.
Short to medium-term safety (6–12 months) reads as acceptable in available data, with the most common adverse effects being injection site reactions, headache, and transient water retention. Long-term human safety past 12 months from published RCTs is basically not available.
The ipamorelin research profile on Next Pep covers the GHS-R1a mechanism, the Teichman 2006 phase I/II human data, pharmacokinetics, and the DAC vs no-DAC distinction in one cross-referenced view. Before you evaluate any vendor, this is the objective baseline that separates what the evidence actually shows from what product listings claim.
Use the comparison tool to put ipa and CJC-1295 alongside sermorelin or other GH secretagogues, comparing half-life, human trial data, and regulatory status side by side. The dosing calculator handles the reco maths for both compounds: enter your vial concentration and target dose and it returns exact draw volume in mL and syringe units. And Next Pep's peptide library covers the full GH secretagogue class so you can verify which compound fits your specific research application.
The stack drives pituitary GH secretion through two separate receptor pathways (GHRH receptor and ghrelin receptor/GHS-R1a), producing an additive GH pulse. The downstream effects people chase are improved body composition (lean gains, fat loss for recomp), better sleep, and faster recovery, though human RCT evidence on those endpoints is thin.
CJC-1295 no-DAC (Mod GRF 1-29) has a 30-minute half-life and produces a short, pulsatile GH release, more like natural GHRH. CJC-1295 DAC has a 6–8 day half-life thanks to albumin binding and produces sustained GH elevation for 6+ days per pin. Most people running the stack pick no-DAC to preserve pulsatile signaling.
Both are FDA Category 2 (2024), so they can't be commercially compounded in the US. They're not controlled substances, personal possession isn't illegal, but they sit in a regulatory grey zone. Both are WADA-prohibited in competitive sport.
Standard play is IGF-1 testing at baseline and 6–8 weeks into the cycle. IGF-1 should sit in the upper quartile of the age-adjusted reference range, not supraphysiological. Fasting glucose, thyroid function, and cortisol get pulled too depending on the clinical context.
From the available human PK data and clinical reports, IGF-1 elevation shows up within 2–4 weeks. Subjective changes in body composition, sleep, and recovery usually land at 6–12 weeks. Those timelines line up with how GH-axis changes show up structurally, but they come from clinical practice observations, not controlled human trials.
Research Disclaimer. All content on Next Pep is for informational and educational purposes only. It does not constitute medical advice, diagnosis, or treatment. Consult a licensed healthcare professional before considering any peptide protocol.
CJC-1295 with DAC has a 6-8 DAY half-life; Modified GRF (1-29) clears in ~30 minutes. Same modified GHRH(1-29) backbone, one bolt-on linker, ~1,000x PK difference.
TB-500 is a 7-aa fragment of thymosin beta-4 (43 aa, ~4,963 Da), not the full protein. Cross-COA review: ~67% of "TB-500" vials are actually full Tβ4.