CJC-1295 + Ipamorelin Research Guide: Mechanism, Preclinical Findings and Handling

CJC-1295 (No DAC) and ipamorelin are supplied together as a co-lyophilized research blend because they sit on complementary branches of the same pituitary signaling axis, not because they are chemically related. One is a stabilized analog of growth-hormone-releasing hormone (GHRH); the other is a selective ghrelin-receptor agonist. This guide covers each peptide, why they are studied as a pair, what the preclinical literature supports, and how to handle and verify the material. For laboratory research use only; not for human consumption. The blend is listed as the CJC-1295 (No DAC) + Ipamorelin research blend.

What the blend is

The blend combines two independently synthesized and verified peptides in one lyophilized vial, in a 1:1 mass ratio (for example 5 mg of each, or 10 mg of each). There is no chemical reaction between them in powder or in solution; the vial is a physical combination.

CJC-1295 (No DAC), also called modified GRF(1-29), is a 29-residue GHRH fragment with four protective substitutions and a mass near 3,368 Da. The "No DAC" designation states that it lacks the albumin-binding drug affinity complex found on the long-acting variant, so its activity is short and time-bounded. This matters because the two forms are often conflated: V8's blend uses the no-DAC form, and the DAC molecule has its own research guide.

Ipamorelin is a synthetic pentapeptide, Aib-His-D-2-Nal-D-Phe-Lys-NH2, with a mass near 711.9 Da. It acts at the growth hormone secretagogue receptor (GHS-R1a), the receptor for ghrelin.

For the broader single-page summary see the research overview and the blend explainer.

Discovery and history

The two peptides come from separate lineages and were never developed together. The GHRH line began with the 1982 purification of the hormone from pancreatic tumors (Guillemin and colleagues; Rivier and colleagues). Native GHRH is degraded within minutes, mainly by dipeptidyl peptidase IV (Frohman et al., 1986), which limited its usefulness as a stable reagent. Substituting specific residues in the 1-29 fragment produced the modified GRF(1-29) that is sold as CJC-1295 without DAC. A separate branch added an albumin-binding maleimide group to create the long-acting DAC form (Jetté et al., 2005); the "CJC" prefix traces to ConjuChem, the company involved. The no-DAC history is in its own article.

The ipamorelin line began with growth hormone secretagogue research in the early 1980s, when Bowers and colleagues described synthetic peptides such as GHRP-6 that release GH through a receptor distinct from the GHRH receptor. That receptor was cloned in 1996 (Howard et al.), and its natural ligand, ghrelin, was identified from stomach in 1999 (Kojima et al.). Early secretagogues were not selective and also raised ACTH, cortisol and prolactin. Ipamorelin was characterized by Raun and colleagues in 1998 as the first selective GH secretagogue, with GH-releasing potency similar to GHRP-6 in their animal models but without the cortisol and ACTH effects.

The pairing followed from the pharmacology. Once a GHRH-receptor agonist and a selective ghrelin-receptor agonist were each characterized, the question of interaction was natural. Neither peptide is an approved medicine; both have remained research chemicals throughout their history. The pair-specific history is in discovery and history.

Chemical structure and synthesis

The two molecules share no structural lineage. CJC-1295 (No DAC) is a truncated, substituted copy of a hormone sequence: D-alanine at position 2 blocks peptidase cleavage, leucine at position 27 replaces an oxidation-prone methionine, and glutamine at position 8 and alanine at position 15 reduce other degradation liabilities. Ipamorelin is a five-residue designed peptide with 2-aminoisobutyric acid at the N-terminus and two D-amino acids, which together make it a compact, protease-resistant ligand with high receptor selectivity. Neither contains methionine or cysteine in the finished sequence, which simplifies storage chemistry.

Both are produced by solid-phase peptide synthesis, cleaved and purified separately by reverse-phase HPLC to remove truncated and deletion products, then combined and lyophilized in one vial. Their very different sizes, charges and stabilities are the reason separate production runs are used rather than synthesis in a single mixture. Background: understanding amino acid sequences, HPLC vs mass spectrometry, and the structure and synthesis article.

Mechanism of action

Two receptors on one cell

Both receptors sit on the same pituitary somatotroph. The GHRH receptor is a class B GPCR coupled to Gs: activation raises cAMP, activates protein kinase A and drives GH gene transcription and release of stored hormone. The ghrelin receptor GHS-R1a couples chiefly to Gq/11, activating phospholipase C, generating IP3 and mobilizing intracellular calcium, which promotes GH release. The two cascades are distinct but converge on the same secretory output.

Why combine them

Pairing a GHRH analog with a secretagogue lets a study ask whether co-activation is additive, synergistic or redundant. In the endocrine literature, GHRH and GH-releasing peptides are generally described as synergistic: the combined GH response exceeds the sum of the single responses. Secretagogue signaling is also described as functionally opposing somatostatin tone, whereas GHRH supplies the primary drive. Co-activation also raises questions about receptor desensitization kinetics over repeated exposure, which cannot be addressed with either peptide alone.

Why the No-DAC form is used in pairs

The short window of CJC-1295 (No DAC) supports designs built around discrete, repeatable stimulation-and-sampling cycles, matching the pulsatile nature of GH secretion. The long-acting DAC form would present a sustained GHRH signal, which answers a different question; that is one reason the no-DAC form is the usual partner in short-interval signaling studies. See mechanism of action, the single-peptide article ipamorelin mechanism, and the side-by-side CJC-1295 vs ipamorelin.

Downstream signaling

Activation of either receptor increases GH-dependent signaling, including hepatic IGF-I production. Receptor-level events remain cleanly separable from that downstream output in a well-controlled assay, so receptor-specific readouts (cAMP versus calcium) should be reported separately rather than collapsed into one aggregate.

Preclinical research findings

Preclinical work splits into two tiers that ask different questions and should not be conflated. The table summarizes what each tier contributes and which published work supports the component peptides. No single paper should be read as validating the combination as a product; the combined-exposure question is the subject of ongoing experimental design.

Study design for a blend

Because two peptides are present, a well-designed protocol includes an arm for each peptide alone alongside the combination, plus vehicle controls. Only then can an effect be attributed to interaction rather than to either component. Typical endpoints are GH pulse amplitude and frequency over a defined window, circulating IGF-I as a downstream marker, and receptor-level binding and signal transduction in cell work.

Cells to whole organisms

Receptor-binding results do not automatically predict behavior in an intact axis, where feedback loops, endogenous hormone tone and receptor turnover all shape the outcome. Both tiers are therefore run in sequence. Background articles: preclinical research and growth-hormone research.

Handling, reconstitution and storage

A co-lyophilized blend behaves like one vial on the bench, but every measured volume carries two analytes. Bring the sealed vial to room temperature, swab the stopper, add bacteriostatic water slowly down the inner glass wall, and swirl; do not shake or vortex. Both peptides dissolve together in one step. The full bench workflow is in CJC-1295 + ipamorelin reconstitution and storage, the generic method is the lyophilized-peptide guide, and a detailed single-peptide walkthrough is in How to Reconstitute Retatrutide: Step-by-Step Lab Protocol. The calculator performs the arithmetic.

The governing relation is concentration (mg/mL) = peptide mass (mg) ÷ diluent volume (mL), applied to each component separately. Label the vial with the concentration of each peptide, not the combined total.

Because the masses are equal, the molar amounts are not: at 2.5 mg/mL of each, CJC-1295 (No DAC) is about 742 µM and ipamorelin about 3,512 µM, since ipamorelin is far lighter. Correct for net peptide content on the COA for exact molar work. Vial capacity limits usable diluent volumes, and very concentrated solutions take longer to clear and magnify measurement error.

Lyophilized powder is the most stable form: cold, dry and dark. Reconstituted solution kept at 2-8 °C is conventionally used within about 28 days, a preserved-container convention rather than a measured stability limit for this blend; for longer holds, single-use aliquots in low-bind tubes thawed once are preferable. Persistent cloudiness, particles or gel-like strands mean the vial should be discarded. See storing research peptides and bacteriostatic water explained.

Purity, COA and quality

For a two-component product, each peptide must be verified independently. A usable certificate of analysis lists HPLC purity and mass identity for both components, shows the chromatograms, and carries a batch number that matches the vial. Expected masses are near 3,368 Da for CJC-1295 (No DAC) and 712 Da for ipamorelin. A label ratio is also worth confirming: because a 1:1 mass ratio is not a 1:1 molar ratio, an assay that quantifies both should reflect that. Check that the stated values agree with theoretical masses and file the batch with each dataset so lot-to-lot differences can be identified later. Batch documents are shown on the COA page; interpretation is covered in CJC-1295 + ipamorelin purity testing, how to read a COA and understanding HPLC purity. Sourcing considerations: where to buy CJC-1295 + ipamorelin.

Related compounds and comparisons

Researchers can also work with the components or neighbours separately. CJC-1295 (No DAC) and ipamorelin are available as single vials for single-peptide arms, which is how comparison arms are built. Alternatives within each class include sermorelin versus ipamorelin and hexarelin versus ipamorelin, and the DAC question is addressed in the DAC versus no-DAC comparison. The principles behind multi-peptide products are in peptide blends and research stacks.

Frequently asked questions

Is the blend the DAC or no-DAC version of CJC-1295?

The no-DAC version. It lacks the albumin-binding drug affinity complex and therefore has a much shorter research half-life than the DAC form. The two are often conflated under the same name.

Why pair a GHRH analog with a ghrelin mimetic?

They act on separate receptors of the same somatotroph and converge on GH release. Pairing lets a study test whether co-activation is additive, synergistic or redundant.

What makes ipamorelin different from GHRP-6?

Selectivity. In Raun et al. (1998), ipamorelin released GH with potency similar to GHRP-6 in their models but without the clear ACTH and cortisol rise seen with earlier secretagogues.

Are the two peptides structurally related?

No. One is a 29-residue substituted GHRH fragment and the other a designed pentapeptide. They are synthesized and purified separately and combined only at the lyophilization stage.

What does each receptor signal through?

The GHRH receptor couples to Gs and raises cAMP. The ghrelin receptor GHS-R1a couples mainly to Gq/11 and mobilizes calcium. Report the two readouts separately.

How do I calculate concentrations for a blend?

Divide the mass of each peptide by the diluent volume. A 5 mg / 5 mg vial reconstituted with 2 mL gives 2.5 mg/mL of each. The calculator automates the math.

Why do the molar amounts differ if the masses are equal?

Ipamorelin is about 712 g/mol and CJC-1295 (No DAC) about 3,368 g/mol, so equal masses contain roughly 4.7 times more moles of ipamorelin.

How long can the reconstituted blend be kept?

Refrigerated at 2-8 °C in bacteriostatic water, laboratories conventionally allow up to about 28 days. That is a container convention, not a measured stability claim; see reconstitution and storage.

How is quality documented?

Each component is tested for HPLC purity and mass identity, consolidated in one batch certificate. See purity testing.

Which controls does a blend study need?

An arm for each peptide alone, the combination, and a vehicle control, with concentration series and time-course sampling. Without single-peptide arms, interaction cannot be separated from either component.

Research Use Only. For laboratory research use only; not for human consumption. Not for veterinary, clinical, or diagnostic purposes. This guide is research education, not usage guidance.

References

1. Guillemin R, Brazeau P, Böhlen P, Esch F, Ling N, Wehrenberg WB. Growth hormone-releasing factor from a human pancreatic tumor that caused acromegaly. Science. 1982;218(4572):585-587.
2. Rivier J, Spiess J, Thorner M, Vale W. Characterization of a growth hormone-releasing factor from a human pancreatic islet tumour. Nature. 1982;300(5889):276-278.
3. Frohman LA, Downs TR, Williams TC, Heimer EP, Pan YC, Felix AM. Rapid enzymatic degradation of growth hormone-releasing hormone by plasma in vitro and in vivo to a biologically inactive product cleaved at the Tyr1-Ala2 bond. J Clin Invest. 1986;78(4):906-913.
4. Jetté L, Léger R, Thibaudeau K, et al. Human growth hormone-releasing factor (hGRF)1-29-albumin bioconjugates activate the GRF receptor on the anterior pituitary in rats: identification of CJC-1295 as a long-lasting GRF analog. Endocrinology. 2005;146(7):3052-3058.
5. 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;91(12):4792-4797.
6. Alba M, Fintini D, Sagazio AM, et al. Once-daily administration of CJC-1295, a long-acting growth hormone-releasing hormone (GHRH) analog, normalizes growth in the GHRH knockout mouse. Am J Physiol Endocrinol Metab. 2006;291(6):E1290-E1294.
7. Teichman SL, Neale A, Lawrence B, Gagnon C, Castaigne JP, Frohman LA. 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;91(3):799-805.
8. Raun K, Hansen BS, Johansen NL, et al. Ipamorelin, the first selective growth hormone secretagogue. Eur J Endocrinol. 1998;139(5):552-561.
9. Bowers CY, Momany FA, Reynolds GA, Hong A. On the in vitro and in vivo activity of a new synthetic hexapeptide that acts on the pituitary to specifically release growth hormone. Endocrinology. 1984;114(5):1537-1545.
10. Howard AD, Feighner SD, Cully DF, et al. A receptor in pituitary and hypothalamus that functions in growth hormone release. Science. 1996;273(5277):974-977.
11. Kojima M, Hosoda H, Date Y, Nakazato M, Matsuo H, Kangawa K. Ghrelin is a growth-hormone-releasing acylated peptide from stomach. Nature. 1999;402(6762):656-660.