Ipamorelin vs CJC-1295: A Research Comparison

Ipamorelin and CJC-1295 No DAC are among the most often paired compounds in growth hormone axis research. The reason is structural: they act on entirely different receptors. This side-by-side look at ipamorelin vs CJC-1295 covers receptor class, selectivity, and duration. It also covers the study designs each one suits. Both are research-use-only materials, and neither is approved for human or veterinary use.

How do Ipamorelin and CJC-1295 differ in receptor target?

Ipamorelin acts on the ghrelin receptor, while CJC-1295 No DAC acts on the GHRH receptor. Growth hormone release from pituitary cells, called somatotrophs, is controlled by more than one upstream input. Each compound probes a different one.

Ipamorelin is a synthetic chain of five amino acids. It is an agonist of the growth hormone secretagogue receptor, GHS-R1a. This is the same G-protein-coupled receptor that natural ghrelin binds.

CJC-1295 No DAC is also known as modified GRF (1-29). It is a 29-amino-acid analog of growth hormone-releasing hormone, or GHRH. It acts at the GHRH receptor.

That difference drives the rest of the comparison. Two agonists at two receptors reach the same cell group through separate second-messenger routes. That is why convergent signaling designs use both, not one or the other.

• Receptor target: ipamorelin acts at GHS-R1a, the ghrelin receptor. CJC-1295 No DAC acts at the GHRH receptor.
• Molecular class: a five-amino-acid secretagogue versus a stabilized GHRH (1-29) analog.
• Molecular weight: about 711.85 g/mol versus about 3367.9 g/mol, close to a fivefold difference in mass.
• Duration in models: both short-acting, for entirely different structural reasons.

How do their mechanisms compare side by side?

Ipamorelin signals through calcium, and CJC-1295 No DAC signals through cAMP.

Ipamorelin has CAS number 170851-70-4 and formula C38H49N9O5. It is derived from the earlier secretagogue GHRP-1. Its sequence is Aib-His-D-2-Nal-D-Phe-Lys-NH2.

In test systems, binding at GHS-R1a is linked to phospholipase C signaling. It is also linked to a rise in calcium inside the cell. In somatotroph models, these events are tied to the release of stored hormone.

GHS-R1a is also found in the hypothalamus and in tissues outside the brain. That matters for study design. The ipamorelin mechanism of action article covers this in more depth.

CJC-1295 No DAC has CAS number 863288-34-0 and formula C152H252N44O42. It copies the active 1-29 fragment of native GHRH, with several amino acid swaps. That is why the literature also calls it tetrasubstituted GRF (1-29) and Mod GRF 1-29.

Those swaps are studied for making it harder for the enzyme dipeptidyl-peptidase to cut. The peptide still engages its receptor. At the GHRH receptor, it is linked to cAMP-driven signaling and the start of pulsed growth hormone release. The CJC-1295 No DAC mechanism of action article sets this out.

The contrast is one of route, not rank. Calcium signals after GHS-R1a and cAMP signals after the GHRH receptor can be measured apart. That makes the pair useful in cell-culture work.

How selective is each compound?

The two compounds are selective against different things, so they cannot be ranked on one scale. Selectivity is the most misread part of this comparison.

Ipamorelin's reported selectivity is within the pituitary. In pituitary and animal models, it promotes growth hormone release. It has fairly little effect on the ACTH and cortisol or prolactin pathways.

A 1998 study by Raun and colleagues called it the first selective growth hormone secretagogue. They described its selectivity as close to that of GHRH itself.

CJC-1295 No DAC is selective in a different sense. As a GHRH analog, it targets the GHRH receptor. That receptor is found in fewer places than the ghrelin receptor. So its off-target concerns sit elsewhere in the model.

Labs often run ipamorelin against GHRP-2, GHRP-6, and hexarelin in studies of receptor selectivity and hormone specificity. There is no direct equivalent family comparison on the GHRH side.

How do duration and stability differ, and what is DAC?

Both compounds are studied as short-acting, but for different reasons. Ipamorelin is short-acting because of the nature of the small peptide itself.

CJC-1295 No DAC is short-acting because something was left out on purpose. It lacks the Drug Affinity Complex, or DAC. DAC is a maleimide group that binds serum albumin. In the DAC-bearing version, it makes the peptide last much longer in circulation.

Leaving it out is a research feature, not a flaw. A short duration lets labs study timed, pulsed receptor signaling. They can avoid steady, constant receptor occupancy.

Teams comparing the two duration profiles in one framework should read the CJC-1295 DAC versus No DAC comparison before finalizing a protocol.

Why are Ipamorelin and CJC-1295 studied together?

They reach the same somatotroph cells by separate routes, so pairing them is a standard way to study combined effects. One is a secretagogue receptor agonist. The other is a GHRH receptor agonist. Labs pair them to study additive or convergent effects on the growth hormone axis in vitro and in animal models.

The literature on CJC-1295 No DAC notes this pairing with GHS receptor agonists such as ipamorelin directly.

For teams running that design, Puritide Research supplies a pre-mixed CJC No DAC / Ipamorelin research blend. It has 10 mg of each compound per vial. This removes one reconstitution step and one source of ratio error.

Some studies need a different ratio. Others need either agonist alone as a control arm. In those cases, the single-compound vials are the better fit.

Which compound fits which research question?

The choice follows from which receptor the question is really about. This avoids handling the two as interchangeable growth hormone tools.

• Ghrelin receptor pharmacology, GHS-R1a kinetics, or selectivity comparisons with other GHRPs: ipamorelin. Its selectivity limits confounding from other pituitary hormones.
• GHRH receptor engagement, cAMP-driven signaling, or pulsed stimulation: CJC-1295 No DAC. It suits timed signaling rather than steady occupancy.
• Convergence, additivity, or cross-talk between the pathways: both, with single-agonist control arms so each share can be traced.
• Ghrelin receptor signaling outside the brain: ipamorelin. One example is rodent gut motility models such as postoperative ileus. Ipamorelin has a preclinical literature base there, and CJC-1295 does not.

What are the specifications, sourcing, and handling steps?

Both come as solid white freeze-dried powder in sealed glass vials. Both are verified to at least 99% purity by third-party HPLC and mass spectrometry. Every lot has a batch certificate of analysis.

Puritide Research sources and independently tests these materials. It does not make them in-house. Labs can request a sample certificate before purchase.

Storage guidance is the same for both:

• Keep the vial sealed at or below 25 degrees Celsius.
• Keep it away from heat, light, and moisture.
• For long storage, keep the material freeze-dried and chilled or frozen.

Record lot numbers and storage conditions through the study. Matching records for both compounds make results across the two easier to defend.

Common research questions

Is ipamorelin more selective than CJC-1295?

Not on any shared scale. Ipamorelin's selectivity is described relative to other pituitary hormone pathways. It has limited effect on cortisol and prolactin in models. CJC-1295 No DAC is selective for the GHRH receptor. The claims describe different comparisons, so neither compound is simply more selective.

Can one substitute for the other in a study?

No. They complement each other and are not interchangeable. Swapping a GHRH analog for a ghrelin receptor agonist changes the receptor under study. It also changes the second-messenger pathway measured. The data would no longer compare with the original design.

Why does the combined preparation use the No-DAC form rather than CJC-1295 with DAC?

The No-DAC form's short duration is closer to that of ipamorelin. So the two act over a broadly similar window in model systems. Pairing a long-acting DAC analog with a short-acting secretagogue creates a duration mismatch. That makes it harder to credit observed signaling to either input.

For research use only. Ipamorelin and CJC-1295 No DAC are laboratory research compounds supplied for in vitro and preclinical investigation. Neither is approved for human or veterinary use, and nothing above is medical guidance or a description of outcomes in people.