CJC-1295 with DAC vs Ipamorelin: Half-Life, Receptors & GH Release Compared
CJC-1295 with DAC runs a 6-8 day half-life against Ipamorelin's 2 hours. Compare the two receptor pathways, GH release patterns and 503A review status.
Research reference only. The information in this article is a summary of peer-reviewed scientific literature. It does not constitute medical advice and is not intended to guide human use. See our full disclaimer.
CJC-1295 with DAC and Ipamorelin are the two compounds most frequently studied together in growth hormone secretagogue research, and the reason is mechanistic rather than incidental: they act on entirely different pituitary receptors and operate on half-lives that differ by roughly two orders of magnitude. CJC-1295 with DAC is a growth hormone-releasing hormone (GHRH) analogue engineered for sustained albumin binding, with a plasma half-life of approximately 6 to 8 days. Ipamorelin is a pentapeptide ghrelin-receptor agonist with a half-life measured in hours. Understanding why researchers pair or separate them requires looking at receptor pharmacology, not at potency alone.
Research reference only. All information on this page is a summary of peer-reviewed scientific literature and does not constitute medical advice. See individual library profiles for full compound data.
Quick Answer: CJC-1295 with DAC is a long-acting GHRH-receptor analogue producing continuous, non-pulsatile growth hormone elevation over 6 to 8 days, while Ipamorelin is a short-acting, selective GHS-R1a (ghrelin receptor) agonist producing discrete pulsatile GH release over roughly 2 hours. They are studied together because they stimulate the same cell through two independent signalling pathways.
TL;DR:
- CJC-1295 with DAC binds the GHRH receptor; Ipamorelin binds the ghrelin receptor GHS-R1a — different receptors, different second-messenger cascades.
- Half-life differential is the defining practical distinction: ~6 to 8 days versus ~2 hours.
- CJC-1295 with DAC produces sustained IGF-1 elevation; Ipamorelin preserves the natural pulsatile GH secretion pattern.
- Ipamorelin is characterised by selectivity — minimal prolactin and cortisol elevation relative to earlier GHRPs such as GHRP-6 and hexarelin.
- Neither compound holds FDA approval; both sit in Under Review status for 503A compounding and both are captured by WADA's S2 category.
CJC-1295 with DAC: mechanism and evidence base
CJC-1295 with DAC is a 30-amino-acid modified GHRH(1-29) analogue carrying a Drug Affinity Complex — a maleimidopropionic acid moiety conjugated at the lysine-30 position. On administration the linker forms a covalent bond with circulating serum albumin, creating a depot that keeps receptor-active analogue in plasma for days rather than minutes. The compound's full profile is catalogued at /library/cjc-1295-dac/.
The pharmacology follows directly from that modification. GHRH receptors on anterior pituitary somatotrophs are stimulated continuously rather than in discrete bursts. Single-dose work in healthy adults reported sustained elevation of growth hormone and IGF-1 across a 6 to 8 day window, with repeated weekly administration supporting cumulative IGF-1 elevation (PMID 16352683). That study remains the primary pharmacokinetic reference for the DAC variant and is the reason weekly dosing intervals appear throughout the subsequent research literature.
The contrast with the unmodified molecule is instructive. Modified GRF (1-29), catalogued as /library/cjc-1295/, lacks the DAC linker and clears with a half-life near 30 minutes, preserving the endogenous pulsatile secretion rhythm. Researchers therefore treat the two as distinct pharmacological models rather than dose-equivalent versions of one compound — a distinction examined in more depth in the site's dedicated DAC comparison article.
The trade-off attached to sustained GHRH stimulation is the loss of pulsatility itself. Endogenous growth hormone is secreted in bursts, and several downstream signalling effects are believed to depend on that pattern. Continuous elevation is a useful experimental model precisely because it isolates the effect of total GH exposure from the effect of secretion rhythm, but it is not a physiological reproduction of normal secretion.
Ipamorelin: mechanism and evidence base
Ipamorelin is a pentapeptide growth hormone secretagogue acting at the growth hormone secretagogue receptor GHS-R1a — the ghrelin receptor — on somatotroph cells. Its profile is catalogued at /library/ipamorelin/. Binding at GHS-R1a amplifies GHRH signalling while simultaneously suppressing somatostatin tone, producing a growth hormone pulse that follows the natural secretion pattern rather than overriding it.
The characteristic most consistently reported in the literature is receptor selectivity. Unlike broader-acting secretagogues, Ipamorelin generates growth hormone release with minimal accompanying prolactin or adrenocorticotropic hormone elevation. That selectivity is the reason it displaced GHRP-6 and hexarelin in much of the research literature, and it is examined against those compounds directly in the GHRP-class comparison already published on this site.
A 2026 critical review of peptide and peptide-analogue use in sport catalogued Ipamorelin alongside CJC-1295 and Sermorelin, characterising the class as having enhanced stability and receptor selectivity relative to earlier agents while noting that clinical evidence remains limited and that most published studies examine controlled therapeutic dosing rather than the combined protocols seen outside research settings (PMID 41880199). The same review documented cardiovascular strain, insulin resistance and dyslipidemia among the risks reported at elevated exposure, and flagged the absence of longitudinal safety data as a standing gap in the literature.
Ipamorelin's short duration is not a limitation in experimental terms — it is the design feature. Discrete pulses can be timed, spaced and counted, which makes the compound a tractable model for studying secretion rhythm rather than cumulative exposure. Related GHS-R1a pharmacology is covered in the /library/sermorelin/ and /library/tesamorelin/ profiles, both GHRH-side compounds that serve as useful contrast points.
Side-by-side comparison
| Property | CJC-1295 with DAC | Ipamorelin |
|---|---|---|
| Receptor target | GHRH receptor (GHRH-R) | Ghrelin receptor (GHS-R1a) |
| Class | GHRH analogue | Growth hormone secretagogue / GHRP |
| Amino acid count | 30 | 5 |
| Molecular weight | 3647.1 g/mol | 711.9 g/mol |
| Plasma half-life | ~6–8 days | ~2 hours |
| GH release pattern | Continuous, non-pulsatile | Discrete, pulsatile |
| IGF-1 effect | Sustained cumulative elevation | Transient, pulse-linked |
| Prolactin / cortisol effect | Not a primary characteristic | Minimal — defining selectivity feature |
| CAS number | 863288-34-0 | 170851-70-4 |
| Development stage | Phase 2 | Phase 2 |
| Regulatory approval | Investigational | Investigational |
| 503A compounding status | Under Review | Under Review |
The half-life column is the one that drives most protocol design decisions in published work. A 6 to 8 day duration and a 2 hour duration cannot be reconciled into a single administration schedule, which is why the two compounds appear on separate timelines even in studies that examine both. Comparative half-life data across the wider secretagogue category is plotted at /tools/half-life-chart/.
Differential research applications
Researchers select CJC-1295 with DAC when the experimental question concerns total growth hormone and IGF-1 exposure over time. The sustained albumin-bound depot removes administration frequency as a confounding variable and produces a stable elevation that can be sampled at intervals across a week. Studies examining IGF-1 accumulation, or those requiring a consistent GH background against which to measure some other intervention, favour this profile.
Ipamorelin is selected when secretion rhythm is the variable of interest, or when the research question requires stimulating the ghrelin pathway specifically. Because GHS-R1a and GHRH-R signal independently, a design using both compounds can dissociate pathway contributions in a way that neither compound alone permits. This is the pharmacological rationale behind the frequent pairing of the two in the literature — not additive potency, but pathway separation.
Selectivity also matters for endpoint design. Ipamorelin's minimal prolactin and cortisol footprint means those hormones can serve as clean control measures rather than as confounders, which is a practical advantage over GHRP-6 or hexarelin in studies where hypothalamic-pituitary-adrenal axis activation would muddy interpretation.
A third consideration is detection. The 2026 review noted that structural homology to endogenous ghrelin combined with rapid peptide catabolism complicates anti-doping detection methodology for compounds in Ipamorelin's class (PMID 41880199). The long-acting DAC variant presents a different analytical profile precisely because it persists. Study designs in the compliance and detection literature therefore treat the two as separate analytical problems. Citation-level evidence for both compounds can be filtered at /tools/evidence-explorer/.
Regulatory and compounding status
Neither compound holds FDA approval for any indication. Both are classified as Investigational at Phase 2 development stage, and both carry Under Review status for inclusion on the FDA's 503A compounding bulk substances list — the same review track covering several other secretagogues examined by the Pharmacy Compounding Advisory Committee. Current status for compounds under that review is tracked at /tools/pcac-tracker/.
Both fall within the World Anti-Doping Agency's S2 category covering peptide hormones, growth factors and related substances, which is prohibited at all times in and out of competition. WADA's 2026 list language extends to substances with similar chemical structure or similar biological effect, which captures analogues of both compounds regardless of individual listing.
Neither compound is approved by the EMA. The GHRH-analogue class does contain one approved agent — Tesamorelin — which provides a useful regulatory contrast, since it demonstrates that GHRH-receptor pharmacology per se is not the barrier to approval.
Cited studies
- PMID 16352683 — "Sustained release of growth hormone-releasing hormone analogue (CJC-1295) in healthy adults." (Journal of Clinical Endocrinology & Metabolism, 2006). https://doi.org/10.1210/jc.2005-1536
- PMID 41880199 — "A new era of doping? Use of peptide and peptide-analog drugs in recreational and professional sport and bodybuilding: a critical review." (2026).
Frequently asked questions
Q: What is the difference between CJC-1295 with DAC and Ipamorelin?
A: They act on different pituitary receptors. CJC-1295 with DAC is a GHRH-receptor analogue producing continuous growth hormone elevation over 6 to 8 days, while Ipamorelin is a ghrelin-receptor (GHS-R1a) agonist producing discrete pulses over roughly 2 hours. The two pathways signal independently of one another.
Q: Why are CJC-1295 and Ipamorelin studied together?
A: Because they stimulate the same somatotroph cells through two separate receptor systems, using both allows researchers to dissociate GHRH-pathway from ghrelin-pathway contributions to growth hormone release. The rationale in published work is pathway separation rather than simple additive effect.
Q: How long is the half-life of CJC-1295 with DAC compared with Ipamorelin?
A: CJC-1295 with DAC has a reported plasma half-life of approximately 6 to 8 days, conferred by covalent albumin binding via its Drug Affinity Complex linker. Ipamorelin's half-life is approximately 2 hours, consistent with rapid catabolism of an unmodified pentapeptide.
Q: Is Ipamorelin more selective than other GHRPs?
A: Published characterisations describe Ipamorelin as producing growth hormone release with minimal prolactin or adrenocorticotropic hormone elevation, distinguishing it from non-selective secretagogues such as GHRP-6 and hexarelin. That selectivity profile is the most frequently cited reason for its use in the research literature.
Q: Are CJC-1295 with DAC and Ipamorelin FDA approved?
A: Neither compound is FDA approved for any indication. Both are classified as Investigational and both carry Under Review status on the FDA's 503A compounding bulk substances track. Both also fall under WADA's S2 prohibited category for peptide hormones and growth factors.
See also:
- CJC-1295 vs CJC-1295 with DAC: Pulsatile vs Sustained GH Release — why the DAC linker alone changes the pharmacological model.
- Ipamorelin vs GHRP-2 vs GHRP-6: Ghrelin Mimetic Comparison — where Ipamorelin's selectivity sits within the wider GHRP class.
- Peptide Half-Life: How Long Do Common Research Compounds Last? — comparative half-life data across the research peptide catalogue.
For laboratory research purposes only. Not for human or animal consumption. Compounds described are not approved by the FDA for human or veterinary use unless explicitly stated.