CJC-1295 No DAC + Ipamorelin UK listings describe a combination of two synthetic peptides that act on different receptors in the anterior pituitary. The first, modified GRF(1-29), is a 29-residue analogue of growth hormone-releasing hormone (GHRH). The second, ipamorelin, is a pentapeptide agonist of the ghrelin receptor. Laboratory studies use each compound to examine growth hormone secretion, receptor signalling and the interaction between two distinct stimulatory pathways in cell culture and animal models. This article summarises their structures, mechanisms, published research areas and the analytical and storage standards that support reproducible work. It is written for laboratory researchers and offers no guidance on human use.
What is CJC-1295 No DAC + Ipamorelin?
The name refers to two separate molecules supplied together, and each needs to be understood on its own terms. Nothing in the published literature describes the mixture as a single compound, so any statement about the combination should be read as a statement about two test articles used in the same vial.
The first component is commonly sold as “CJC-1295 without DAC” or “CJC-1295 No DAC”. This is a naming habit of the supply market. Chemically it is modified GRF(1-29), sometimes written Mod GRF(1-29), a 29-residue peptide derived from the shortest fragment of human GHRH that retains full receptor activity. Four substitutions relative to the native fragment are usually described: D-alanine at position 2, glutamine at position 8, alanine at position 15 and leucine at position 27. These changes improve resistance to dipeptidyl peptidase IV (DPP-IV) cleavage and stabilise the helical structure. The peptide is C-terminally amidated, and its molecular weight is approximately 3368 Da. The “DAC” in the longer name refers to a drug affinity complex, a reactive linker that binds the peptide covalently to serum albumin. The No DAC form lacks that linker, so it is cleared far faster than the albumin-conjugated version, and results from one form cannot be applied to the other.
The second component, ipamorelin, has the sequence Aib-His-D-2-Nal-D-Phe-Lys-NH2, where Aib is alpha-aminoisobutyric acid and D-2-Nal is D-2-naphthylalanine. Its molecular formula is C38H49N9O5 and its molecular weight is about 712 Da. It was developed by Novo Nordisk in the 1990s as a growth hormone secretagogue, and its characterisation was reported by Raun and colleagues in 1998 in the European Journal of Endocrinology. Clinical development was not pursued to authorisation, and the compound is not an authorised medicine in the United Kingdom.
Regulatory context matters for any UK buyer. Neither peptide is authorised as a medicine in the United Kingdom, and both appear on the World Anti-Doping Agency prohibited list. The Medicines and Healthcare products Regulatory Agency (MHRA) has issued public warnings about unlicensed products marketed for human use. These materials are relevant here only as laboratory research reagents.
Mechanism of action
The two peptides work through different G protein-coupled receptors on the same cell type, the somatotroph of the anterior pituitary, and the interest in studying them together comes from that difference.
Modified GRF(1-29) is an agonist at the GHRH receptor (GHRH-R), a class B receptor that couples to the stimulatory G protein, Gs. Activation of adenylyl cyclase raises intracellular cyclic AMP (cAMP), and protein kinase A then phosphorylates targets including the transcription factor CREB. This promotes expression of the growth hormone gene and of the pituitary transcription factor Pit-1, and it increases the release of stored growth hormone from secretory granules.
Ipamorelin is an agonist at the growth hormone secretagogue receptor type 1a (GHS-R1a), the receptor for the endogenous peptide ghrelin. This is a class A receptor that couples mainly to Gq/11. Signalling proceeds through phospholipase C, generation of inositol trisphosphate and diacylglycerol, release of calcium from intracellular stores and activation of protein kinase C. The pathway is distinct from the cAMP route used by GHRH-R, although the two converge on hormone release.
The classical observation, first made with earlier secretagogues in the 1980s, is that stimulation of both receptors together produces a growth hormone response larger than the sum of the individual responses. The proposed explanations include convergence of the cAMP and calcium pathways, suppression of somatostatin tone by the secretagogue and amplification of GHRH release at the hypothalamic level. In an isolated pituitary cell system only the direct pituitary component can be observed, whereas in a whole animal the hypothalamic and feedback contributions also operate. Interpretation therefore depends strongly on the model.
Ipamorelin has been described as selective for growth hormone release, with little effect on adrenocorticotropic hormone (ACTH) and cortisol in the animal models used, in contrast with some older secretagogues. That selectivity claim comes from specific models and doses and should be checked against the primary paper.
In cell-based work, each peptide is usually tested in receptor-expressing cell lines or primary pituitary cultures. Readouts include cAMP accumulation and reporter assays for GHRH-R, calcium flux and inositol phosphate assays for GHS-R1a, and growth hormone released into the medium. In these systems, “dosage” means molar concentration in the medium, which depends on net peptide content, adsorption to plasticware and protease activity in any serum used.
What the research shows
The literature on these two peptides is uneven. Modified GRF(1-29) has a modest body of work, ipamorelin a smaller one, and the combination has not been studied as a defined product. Four areas are summarised below in general terms. Readers should consult the primary papers for methods, concentrations and statistics, because commercial summaries often overstate findings.
The first area is the characterisation of ipamorelin. Raun and colleagues described it in 1998 as a selective growth hormone secretagogue, comparing it with GHRP-6 and related compounds in cultured rat pituitary cells and in rats and swine. They reported that it released growth hormone in a dose-related manner in these systems and that, unlike some comparators, it did not produce significant increases in ACTH or cortisol at the exposures tested. Exposures in the animal experiments were expressed per kilogram of body weight and differ with species and route, so they should be taken directly from the paper. The original work can be located through a PubMed search for the ipamorelin characterisation study.
The second area is the design of modified GHRH analogues. Studies of GRF(1-29) analogues examined how substitutions at positions 2, 8, 15 and 27 affect receptor potency and resistance to enzymatic degradation, using pituitary cell assays and rodent models. This work established why the D-alanine at position 2 slows DPP-IV cleavage, and it supplies the structural logic for the modified peptide supplied as CJC-1295 No DAC. These papers describe peptide chemistry and receptor pharmacology, and they say nothing about use outside the laboratory.
The third area is the synergy between GHRH and secretagogue pathways. Early work with GHRP-6 and related peptides showed that the combination of a GHRH and a GHRP produced a larger growth hormone response than either alone in cultured pituitary cells and in animal studies. Later studies refined the mechanism, including the roles of somatostatin and hypothalamic GHRH release. The topic can be explored through a PubMed search for GHRH and GHRP synergy in growth hormone release.
The fourth area is the pattern of secretion. Work on the albumin-conjugated analogue examined whether continuous receptor stimulation abolishes the natural pulsatile pattern of growth hormone release, and reported that pulsatility persisted with raised baseline levels. This was a clinical pharmacology investigation of the DAC form conducted under ethical approval. It is cited here only as part of the scientific record, and it does not describe the No DAC form.
A recurring limitation runs through this body of work. Studies use different species, routes and vehicles, the compounds are not always characterised analytically, and the supply-market name “CJC-1295” is applied to more than one molecule. Reproducibility therefore depends on knowing exactly which materials were used.
Research applications
In the laboratory, the two components serve several purposes. The most common is receptor pharmacology, where modified GRF(1-29) is used as a reference agonist at GHRH-R and ipamorelin as a selective agonist at GHS-R1a. They are used to characterise signalling, benchmark novel ligands and validate cAMP, calcium and reporter assays.
A second context is the study of pathway interaction. Cultured pituitary cells and receptor-expressing co-culture systems allow researchers to test how simultaneous activation of a Gs-coupled and a Gq-coupled receptor shapes hormone release, with each peptide also run alone and with a vehicle control. This design is essential, because attributing an effect to the combination requires showing that it exceeds the individual components.
A third context is neuroendocrine physiology in animal models, where the compounds probe the dynamics of the growth hormone axis, somatostatin tone and the balance between pulsatile and tonic stimulation. These experiments require institutional ethical review and, in the United Kingdom, authorisation under the Animals (Scientific Procedures) Act 1986.
A fourth context is analytical and anti-doping science. Both peptides appear on the World Anti-Doping Agency prohibited list, and reference samples of defined identity and purity are used to develop and validate liquid chromatography and mass spectrometry methods for detecting growth hormone secretagogues and GHRH analogues. For this purpose, accurate mass and quantified purity are essential.
Across these settings, the sensible meaning of exposure is a defined concentration or per-kilogram quantity, justified by prior literature and verified by analytical characterisation of the material actually used.
Purity, storage and handling
A mixed product raises the bar for quality control, because purity has to be shown for each component and not for the vial as a whole. Reversed-phase high-performance liquid chromatography (HPLC) with UV detection at 214 or 220 nm is the standard method, and a suitable gradient should resolve both peptides, which differ greatly in size and hydrophobicity. Ipamorelin contains a naphthylalanine residue that absorbs strongly at longer wavelengths, so a second wavelength such as 280 nm helps to identify it. A single headline purity figure for a blend says little. The useful information is a chromatogram in which each peak is identified, with purity reported for each component.
HPLC must be paired with mass spectrometry. The expected masses are about 3368 Da for modified GRF(1-29) and about 712 Da for ipamorelin. A mass near 3358 Da for the larger peptide could suggest a missing or altered residue, and a mass about 16 Da higher than expected indicates oxidation. A clean peak at the wrong mass is a clean peak of the wrong compound.
A batch-specific certificate of analysis matters more for a blend than for a single peptide. It should carry a lot number matching the vial, the HPLC result for each component, the observed and theoretical masses, the test date and the quantified amount of each peptide. Net peptide content differs between components because of counterions and water, so a stated total mass does not tell the researcher how much of each peptide is present, and any error feeds directly into concentration-response comparisons.
Because a 29-residue peptide degrades faster once dissolved, and because mixing two peptides in solution can complicate stability, batch-level verification matters more here than with short, robust compounds. UK laboratories sourcing CJC-1295 No DAC + Ipamorelin UK preparations should expect a batch-specific certificate of analysis with component-level data and lyophilised storage at -20°C, and the same documentation standard applies when weighing any best peptides supplier uk claim, since a supplier’s analytical record rather than its search ranking shows whether the vial matches its stated specification.
Lyophilised blends are generally stored at -20°C in a sealed container with desiccant, and many laboratories use -80°C for long-term archives. Vials should reach room temperature before opening so that condensation does not form on the cold powder. After reconstitution, stability falls. Standard practice is to dissolve the peptides in sterile water or a suitable buffer, divide the solution into single-use aliquots and freeze them to avoid repeated freeze-thaw cycles. Refrigerated storage at 2 to 8°C is sometimes used for solutions consumed within days, but the acceptable period should be validated for the assay concerned, preferably by re-running HPLC on stored solution. The glutamine, asparagine and aspartate residues in the larger peptide are susceptible to deamidation and isomerisation at neutral to alkaline pH, and the tyrosine residues can oxidise.
Light sensitivity is a secondary but genuine concern. Aromatic residues, including the naphthylalanine of ipamorelin, can undergo photo-oxidation, so amber vials or dark storage are advisable. Peptides also adsorb to glass and some plastics at low concentrations, so low-bind tubes are preferred for dilute working solutions.
Frequently asked questions
What is CJC-1295 No DAC + Ipamorelin?
It is a combination of two separate research peptides: modified GRF(1-29), a GHRH analogue of about 3368 Da, and ipamorelin, a ghrelin receptor agonist of about 712 Da. They act on different pituitary receptors. The blend itself has no published studies, so research relates to each component.
What is the difference between CJC-1295 with DAC and No DAC?
The DAC form carries a linker that binds serum albumin, extending its half-life. The No DAC form is modified GRF(1-29) without that linker and is cleared much faster. They differ in molecular weight and behaviour, so results from one form should not be applied to the other.
How should CJC-1295 No DAC + Ipamorelin be stored for research?
Keep lyophilised material at -20°C, or -80°C for long-term archiving, in a sealed, dry, light-protected container. Allow vials to reach room temperature before opening. After reconstitution, aliquot and freeze the solution to avoid repeated freeze-thaw cycles and prolonged storage in solution.
How can I verify the quality of a CJC-1295 and ipamorelin batch?
Request a batch-specific certificate showing HPLC data and mass spectrometry confirmation for each peptide, near 3368 Da and 712 Da, with quantified amounts and a lot number matching the vial. For critical work, independent testing by an accredited analytical laboratory provides further assurance.
CJC-1295 No DAC and ipamorelin are supplied for in-vitro laboratory research only and are not intended for human or veterinary use.
