CJC-1295 + Ipamorelin: Two GH Pathways in One Vial

CJC-1295 and ipamorelin are two growth hormone-releasing peptides that act on different receptors. CJC-1295 (without DAC) is a modified GHRH(1-29) that activates the GHRH receptor. Ipamorelin is a pentapeptide that activates the ghrelin receptor (GHSR). Both signal to the same pituitary cells, which is why they are often studied together and supplied as a combined vial.

For laboratory research use only. The compounds discussed are not approved for human or veterinary use and are not drugs, foods or cosmetics. This article summarises published research and is not medical advice.

Key points

Two pathways: GHRH receptor (CJC-1295) and ghrelin receptor (ipamorelin).
Our blend: 5 mg CJC-1295 (no DAC) + 5 mg ipamorelin per vial.
Both components are short-acting; the no-DAC form is chosen to match ipamorelin’s profile.
Each component has its own literature; the blend itself has not been studied in peer-reviewed trials.
Very different masses (3368 vs 712 Da) make identity testing straightforward.

The two components

	CJC-1295 (no DAC)	Ipamorelin
Length / mass	29 aa / ~3368 g/mol	5 aa / 711.9 g/mol
Receptor	GHRH receptor (GPCR, mainly cAMP signalling)	GHSR-1a (ghrelin receptor; constitutively active GPCR)
Origin	GHRH(1-29) with four stabilising substitutions	GHRP-1-derived secretagogue
Duration	Short (no albumin binding)	Terminal half-life ~2 h in humans
Key reference	DAC-form human data: Teichman et al., 2006	Raun et al., 1998; Gobburu et al., 1999

The CJC-1295 (no DAC) + ipamorelin blend is supplied as a 10 mg (5 + 5) vial. Individual components: CJC-1295 and ipamorelin.

Why the two pathways are studied together

The GHRH receptor is a class B G-protein-coupled receptor on pituitary somatotrophs that signals mainly through cAMP (Halmos et al., 2025). GHSR is a different GPCR, with constitutive activity regulated up by ghrelin and down by LEAP2 (Cornejo et al., 2021). Activating both converges on GH secretion through distinct intracellular routes. In the ipamorelin discovery work, antagonist profiling showed that ipamorelin’s GH release went through a GHRP-type receptor, not the GHRH receptor (Raun et al., 1998). That separation is the basis for studying the two classes in combination.

What is known about each component

Ipamorelin released GH in rats and swine with potency similar to GHRP-6, without significant ACTH or cortisol rises in swine (Raun et al., 1998). In humans, a 15-minute infusion produced a single GH episode peaking at about 40 minutes; terminal half-life was about 2 hours (Gobburu et al., 1999).
CJC-1295 human data come mainly from the DAC form, which raised GH 2- to 10-fold for 6 days or more after one dose (Teichman et al., 2006). The no-DAC form in this blend is short-acting by design, so these DAC results do not describe its time course.

Reconstitution and concentrations

Solvent	CJC-1295	Ipamorelin	Molar ratio (Ipa : CJC)
1.0 mL	5 mg/mL	5 mg/mL	~4.7 : 1
2.0 mL	2.5 mg/mL	2.5 mg/mL	~4.7 : 1
3.0 mL	1.67 mg/mL	1.67 mg/mL	~4.7 : 1

Equal weights do not mean equal numbers of molecules. Because ipamorelin is about 4.7 times lighter, the vial contains about 4.7 ipamorelin molecules for every CJC-1295 molecule. Both peptides dissolve readily in water; add bacteriostatic water slowly and swirl. Use the peptide reconstitution calculator one component at a time, and see how to reconstitute peptides.

Testing the blend

The components differ by about 2650 Da, so MS identifies each without ambiguity, and they elute at very different HPLC retention times. GHRH analogues including CJC-1295 have validated LC-MS/MS methods with detection limits at or below 1 ng/mL (Memdouh et al., 2021). The certificate of analysis should report both components.

Open questions

Does combined GHRH-receptor and GHSR stimulation with these two specific peptides produce additive or synergistic GH responses? Peer-reviewed data on this pairing are lacking.
Do the two peptides affect each other’s stability in a shared solution over weeks at 2–8 °C?
Is the conventional 1:1 weight ratio optimal for any research endpoint, given the ~4.7:1 molar imbalance?

Related research

Frequently asked questions

What is CJC-1295 with ipamorelin?

It is a combination of two peptides that stimulate growth hormone through different receptors: CJC-1295 without DAC (a GHRH-receptor agonist) and ipamorelin (a ghrelin-receptor agonist). Our blend contains 5 mg of each in one vial.

What is the difference between CJC-1295 and ipamorelin?

CJC-1295 is a 29-residue modified GHRH analogue acting on the GHRH receptor. Ipamorelin is a 5-residue peptide acting on the growth hormone secretagogue (ghrelin) receptor. They have different sizes, receptors and pharmacology.

Why combine a GHRH analogue with a GH secretagogue?

GHRH-receptor and ghrelin-receptor signalling act on pituitary somatotrophs through different pathways that converge on GH release, so researchers study them together to examine combined stimulation. We are not aware of peer-reviewed trials of this specific blend.

Is the CJC-1295 in the blend with or without DAC?

Without DAC (Mod GRF 1-29), which is short-acting like ipamorelin.

How do I calculate concentrations for the blend?

Calculate each peptide separately. A 10 mg (5 + 5) vial in 2 mL gives 2.5 mg/mL of each peptide.

References

Raun K, et al. Ipamorelin, the first selective growth hormone secretagogue. Eur J Endocrinol. 1998. PMID: 9849822 https://pubmed.ncbi.nlm.nih.gov/9849822/
Gobburu JV, et al. Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteers. Pharm Res. 1999. PMID: 10496658 https://pubmed.ncbi.nlm.nih.gov/10496658/
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. PMID: 16352683 https://pubmed.ncbi.nlm.nih.gov/16352683/
Halmos G, et al. Growth hormone-releasing hormone receptor (GHRH-R) and its signaling. Rev Endocr Metab Disord. 2025. PMID: 39934495 https://pubmed.ncbi.nlm.nih.gov/39934495/
Cornejo MP, et al. The ups and downs of growth hormone secretagogue receptor signaling. FEBS J. 2021. PMID: 33460513 https://pubmed.ncbi.nlm.nih.gov/33460513/
Memdouh S, et al. Advances in the detection of growth hormone releasing hormone synthetic analogs. Drug Test Anal. 2021. PMID: 34665524 https://pubmed.ncbi.nlm.nih.gov/34665524/