CJC-1295 vs Ipamorelin — Canada Research Comparison
CJC-1295 is a long-acting GHRH receptor analogue and ipamorelin is a selective ghrelin receptor agonist — they act on different pituitary receptors and are studied together as a complementary GH-secretagogue research stack, not as competitors.
At a glance
CJC-1295 and ipamorelin are frequently described as "the two halves of the same stack". They are not competing products — they act on distinct pituitary receptors, via distinct signalling cascades, to produce a combined growth hormone pulse that is larger than either peptide alone. Framing them as rivals misrepresents the published pharmacology.
Key facts
| Feature | CJC-1295 (with DAC) | Ipamorelin |
|---|---|---|
| Class | GHRH analogue | Selective ghrelin receptor agonist |
| Receptor | GHRH receptor (somatotroph) | GHS-R1a (ghrelin receptor) |
| Length | 30 residues | 5 residues (pentapeptide) |
| Sequence | Modified GRF (1-29) + DAC linker | Aib-His-D-2-Nal-D-Phe-Lys-NH₂ |
| Molecular weight | ~3,367.88 g/mol | 711.86 g/mol |
| Half-life | 6–8 days (DAC); ~30 min (no-DAC) | ~2 hours |
| GH release pattern | Sustained (DAC) or pulsatile (no-DAC) | Pulsatile |
| Selectivity | GHRH receptor specific | GH only — no ACTH/cortisol/prolactin rise |
| Approval (Canada) | None | None |
Mechanism contrast
CJC-1295 binds the GHRH receptor, a class B GPCR coupled primarily to Gαs and cAMP. Activation triggers GH synthesis and release from pituitary somatotrophs. The DAC variant adds a maleimidopropionyl lysine that binds covalently to free cysteine on albumin, effectively producing an albumin-conjugated prodrug with a 6–8 day plasma half-life.
Ipamorelin binds GHS-R1a, the ghrelin receptor, which couples through Gαq/phospholipase C. The downstream calcium response triggers GH release via a parallel but distinct pathway from GHRH signalling. Because the two receptors are independent, their effects on GH release add rather than substitute.
The stacking rationale
Bowers and colleagues (JCEM 1990) showed in early work on GHRP that combining a GHRH analogue with a ghrelin-class secretagogue produced larger GH peaks than either compound alone in human subjects. That synergy is the scientific basis for the CJC-1295 + ipamorelin research pair — CJC-1295 supplies tonic GHRH receptor drive (sustained with DAC, pulsatile without), while ipamorelin provides a clean GHS-R1a pulse without the off-target cortisol and prolactin elevations associated with GHRP-2 or the appetite stimulation associated with GHRP-6.
Evidence quality
CJC-1295 has one notable human dataset — Teichman et al. (JCEM 2006) — showing dose-dependent and sustained GH and IGF-1 elevation in healthy adults. Ipamorelin is supported by Raun et al. (European Journal of Endocrinology 1998) in rats and pigs plus several small human studies in postoperative ileus. Both compounds remain preclinical for any chronic research use and have no large Phase 3 programmes.
Regulatory status
Neither CJC-1295 nor ipamorelin is approved by Health Canada or any other major regulator.
Related briefs
Frequently asked questions
Are CJC-1295 and ipamorelin competitors or complements?
What is the difference between CJC-1295 with DAC and no-DAC?
Why is ipamorelin preferred over GHRP-2 and GHRP-6 in research stacks?
Are either compound approved in Canada?
References
- [1]Teichman SL, Neale A, Lawrence B, et al.. A Growth Hormone Releasing Factor Analog, CJC-1295, Stimulates Sustained Growth Hormone Secretion. Journal of Clinical Endocrinology and Metabolism, 2006. PMID: 15769748
- [2]Raun K, Hansen BS, Johansen NL, et al.. Ipamorelin, the first selective growth hormone secretagogue. European Journal of Endocrinology, 1998. PMID: 9849822
- [3]Bowers CY, Reynolds GA, Durham D, et al.. On the actions of the growth hormone-releasing hexapeptide, GHRP. Journal of Clinical Endocrinology and Metabolism, 1990. PMID: 1900087
- [4]National Center for Biotechnology Information. PubChem CID 9831659 — Ipamorelin, 2024