CJC-1295 vs Ipamorelin: and why they're paired
CJC-1295 vs ipamorelin comes down to two receptors: CJC-1295 is a modified GHRH analog, while ipamorelin is a ghrelin-receptor agonist. Because they stimulate growth hormone through separate pathways, the CJC-1295/Ipamorelin combination is one of the most studied research blends. CJC-1295 with DAC binds albumin and lasts for days; the no-DAC form (used in our blend) acts for a much shorter time. All forms here are supplied for laboratory research use only.
Side-by-side comparison
| CJC-1295 | Ipamorelin | |
|---|---|---|
| Class | GHRH analog | Ghrelin-receptor agonist (GHRP) |
| Receptor | GHRH receptor | GHS-R1a |
| Length | 30 amino acids (modified GHRH 1-29) | 5 amino acids |
| Duration | Days with DAC; much shorter without DAC | Short-acting |
| Key research | Human study of prolonged GH/IGF-1 rise (DAC) | Animal studies of selective GH release |
Two receptors, two mechanisms
CJC-1295 is a modified GHRH(1-29) analog acting on the GHRH receptor; ipamorelin is a five-residue ghrelin mimetic acting on GHS-R1a. Both stimulate pituitary somatotrophs, but through separate receptors and separate signalling routes.
Because the pathways are distinct, the pairing is a receptor-level rationale rather than a duplication — which is exactly why the two appear together so often in the literature and in commercial blends.
DAC vs no DAC
DAC (Drug Affinity Complex) is a maleimide group that lets CJC-1295 bind covalently to albumin in the blood, shielding it from clearance. In healthy adults, CJC-1295 with DAC raised GH and IGF-1 for several days after a single administration (Teichman et al., 2006), and GH continued to be released in pulses rather than continuously (Ionescu & Frohman, 2006).
Without DAC, the peptide — also called modified GRF(1-29) — is cleared within minutes to hours. It is a different molecule with a different pharmacokinetic profile, and it is the form typically paired with ipamorelin.
- With DAC: albumin-bound, multi-day half-life reported in human study data.
- Without DAC: short-acting, closer to a pulse of GHRH signalling.
- The human duration data apply to the DAC form only and cannot be transferred to the no-DAC blend component.
What the human CJC-1295 studies established
Teichman et al. (2006) reported prolonged elevation of GH and IGF-1 in healthy adults after CJC-1295 with DAC, with a terminal half-life in the range of days. Ionescu and Frohman (2006) showed that despite continuous stimulation, GH secretion remained pulsatile — the pituitary's own rhythm was not flattened.
These are pharmacodynamic and pharmacokinetic findings in small healthy-adult studies, not outcome trials.
What the ipamorelin study established
Ipamorelin was characterised as a selective GH secretagogue that did not markedly raise ACTH or cortisol in animal studies, unlike earlier GHRPs such as GHRP-6 (Raun et al., 1998). The work was conducted in rats and swine, so it is preclinical evidence about selectivity rather than human outcome data.
What has not been established for the blend
No controlled study of the combined CJC-1295 + ipamorelin formulation is cited on this page. The rationale for combining them is receptor-level, and synergy between the two pathways is a hypothesis rather than a demonstrated result in a published combination trial.
The ratio in a blend vial is a commercial specification, not a published optimised ratio, and the blend uses the no-DAC form — so the multi-day duration seen in the DAC human study does not describe the blend.
Interpreting the evidence in laboratory research
GH release is episodic, so single-timepoint sampling can misrepresent an effect; serial sampling or an integrated measure is more informative, with IGF-1 as a slower downstream proxy.
Study designs should state clearly which CJC-1295 form is in use. Mixing DAC and no-DAC results, or reading blend behaviour from single-agent data, is the most common interpretation error in this area.
Handling in the lab
Keep lyophilised vials cold, dry and away from light. Reconstitute with bacteriostatic water using sterile technique, refrigerate the solution, and aliquot to avoid repeated freeze-thaw cycles. For blends, record which component ratio and lot were used.
Frequently asked questions
What is the difference between CJC-1295 and ipamorelin?
CJC-1295 is a GHRH analog acting on the GHRH receptor; ipamorelin acts on the ghrelin receptor GHS-R1a.
Which CJC-1295 is in the CJC-1295/Ipamorelin blend?
Our blend uses CJC-1295 without DAC. CJC-1295 with DAC is sold separately.
What does DAC do?
DAC lets CJC-1295 bind albumin, extending its activity from minutes to days in published human data.
Is CJC-1295 with DAC the same molecule as the no-DAC form?
No. They differ by the DAC group, and their pharmacokinetics differ substantially. Data on one do not describe the other.
What is modified GRF(1-29)?
Another name for the no-DAC form of CJC-1295 — a modified 29-amino-acid GHRH fragment that is cleared quickly.
Does CJC-1295 flatten natural GH pulses?
In the published human study, GH secretion remained pulsatile during continuous stimulation by the DAC form (Ionescu & Frohman, 2006).
Is there a published study of the blend itself?
No controlled study of the combined formulation is cited here. The evidence covers the components separately.
Is the 1:1 blend ratio research-based?
No. It is a commercial product specification, not a published optimised ratio.
What was the ipamorelin selectivity finding?
In rat and swine studies it released GH without markedly raising ACTH or cortisol, unlike earlier GHRPs such as GHRP-6 (Raun et al., 1998).
Are either of these approved medicines?
No. Neither CJC-1295 nor ipamorelin is an approved medicine; both are supplied here for laboratory research only.
Can I buy CJC-1295 and ipamorelin separately?
Yes. CJC-1295 with DAC and ipamorelin are sold individually, and CJC-1295 (no DAC) + ipamorelin is sold as a blend, for laboratory research only. See our research peptides guide research peptides guide for how to compare suppliers and read test documents.
Product pages: CJC-1295 / Ipamorelin blend · CJC-1295 with DAC · Ipamorelin
How should the CJC-1295/ipamorelin blend be stored?
Keep lyophilised vials cold, dry and away from light; refrigerate reconstituted solutions. See our research peptides guide research peptides guide for how to compare suppliers and read test documents.
Is this product for human use?
No. PeptidesDirect sells this compound for laboratory research only. It is not a drug, food or cosmetic and is not for human or veterinary use. This page summarises published research and is not dosing or medical guidance.
Shop the compounds covered in these FAQs: CJC-1295 / Ipamorelin blend · CJC-1295 with DAC · Ipamorelin
References
- Teichman SL, et al. Prolonged stimulation of growth hormone (GH) and insulin-like growth factor I secretion by CJC-1295, a long-acting analog of GH-releasing hormone, in healthy adults. J Clin Endocrinol Metab. 2006. PubMed 16352683
- Ionescu M, Frohman LA. Pulsatile secretion of growth hormone (GH) persists during continuous stimulation by CJC-1295, a long-acting GH-releasing hormone analog. J Clin Endocrinol Metab. 2006. PubMed 17018654
- Raun K, et al. Ipamorelin, the first selective growth hormone secretagogue. Eur J Endocrinol. 1998. PubMed 9849822
Research compounds
Related guides
- Tesamorelin vs Ipamorelin
- CJC-1295/Ipamorelin blend guide
- GH peptide comparison
- Research peptides guide
Research Use Only. Not for human or veterinary use. Not dosing or medical guidance.
