CJC-1295 and Ipamorelin are two distinct peptides — a GHRH analog and a ghrelin receptor agonist — consistently researched together because they act on independent but convergent pathways in the hypothalamic-pituitary GH axis. Where most single GH secretagogues either extend baseline GH output (GHRH class) or induce discrete pulses (GHS class), the CJC-1295 / Ipamorelin combination approximates the two-signal architecture of natural pulsatile GH regulation. Both are research peptides; neither is FDA-approved.
CJC-1295 (with DAC): a synthetic 29-amino-acid analog of GHRH 1-29, engineered for extended half-life via the Drug Affinity Complex (DAC) technology — a maleimidoproprionic acid modification at Lys38 that forms a covalent, reversible bond with endogenous albumin after injection. Molecular weight (with DAC): ~3,647 Da. Half-life: 6–8 days with DAC; ~30 minutes without DAC. CAS (with DAC): 863288-34-0.
Ipamorelin: a synthetic pentapeptide (5 amino acids) and selective ghrelin receptor (GHS-R1a) agonist developed at Novo Nordisk, with high selectivity — minimal effects on cortisol, prolactin, or ACTH. Molecular formula: C38H49N9O5. Molecular weight: 711.9 Da. CAS: 170851-70-4.
CJC-1295 (GHRH analog): binds and activates GHRH receptors on anterior pituitary somatotroph cells, promoting GH gene transcription and sustained secretion, increasing GH pulse amplitude. DAC modification extends receptor occupancy from minutes to days.
Ipamorelin (GHS-R1a agonist): acts on ghrelin receptors in both hypothalamus and pituitary. In the hypothalamus, GHS-R1a activation suppresses somatostatin (the GH-inhibitory signal). At the pituitary, it potentiates GH release through a cAMP-independent, IP3-dependent pathway distinct from GHRH signaling — triggering discrete, pulsatile GH spikes additive to CJC-1295's sustained signal.
Synergistic combination: the two peptides act through different receptors (GHRHR vs. GHS-R1a) via different intracellular cascades. Together, they simultaneously amplify the stimulatory signal (GHRH pathway) and suppress the inhibitory signal (somatostatin). Research estimates their combination produces 3–5× greater total GH secretory area versus either peptide alone.
CJC-1295 Human Trial (Ionescu & Frohman, J Clin Endocrinol Metab, 2006, PMID 16352683): Single-dose and multi-dose SC CJC-1295 in healthy adults produced dose-dependent, sustained GH and IGF-1 elevations. Mean IGF-1 increases of 44–55% sustained at 28 days with once-weekly or twice-monthly dosing.
Ipamorelin Selectivity (Raun et al., Eur J Endocrinol, 1998, PMID 10496658): Foundational characterization demonstrated potent GH secretion with selectivity — no significant cortisol, prolactin, or ACTH elevation at doses producing maximal GH response, a major advantage over GHRP-2 and GHRP-6.
The CJC-1295 / Ipamorelin combination is studied in: GH axis pharmacology, pulsatile GH secretion modeling, body composition research, metabolic rate and fat oxidation, IGF-1 regulation, and GH-deficiency models.
CJC-1295 with DAC — form: lyophilized powder; purity: ≥98% HPLC; storage: −20°C; reconstitution reference: bacteriostatic water. Ipamorelin — form: lyophilized powder; purity: ≥98% HPLC; storage: −20°C; reconstitution reference: bacteriostatic water.
For research use only. Not for human therapeutic use. Neither peptide is FDA-approved.
They target different receptors via different signaling pathways. CJC-1295 maintains a sustained GHRH signal; Ipamorelin simultaneously suppresses hypothalamic somatostatin while independently stimulating pituitary GH release — producing amplified, more physiologically pulsatile GH output than either peptide alone.
The DAC modification bonds covalently to albumin after injection, extending half-life from ~30 minutes to approximately 6–8 days. Without DAC (Mod GRF 1-29) behaves like a slightly more stable version of native GHRH and requires more frequent dosing in research protocols.
A published Phase 1/2 study (Ionescu & Frohman, 2006) showed mean IGF-1 increases of 44–55% sustained at 28 days following once-weekly or twice-monthly dosing of CJC-1295.
No. Neither CJC-1295 nor Ipamorelin is FDA-approved. Both are research peptides available for in-vitro laboratory research use only.