CJC-1295 + Ipamorelin (5mg/5mg) · Research brief

CJC-1295 No DAC Research Peptide vs DAC: Key Differences

Real Peptides Research TeamEditorial

Updated September 28, 20269 min read

60 WORDS

Short answer

Two vials, one molecule, one linker. The difference between a CJC-1295 No DAC research peptide and the DAC version is not potency at the receptor, it is duration in circulation. Published clinical work on the DAC form in healthy adults reported a mean terminal half-life in the range of roughly 5.8 to 8.1 days, with IGF-I elevated for about 9…

Key takeaways

A CJC-1295 No DAC research peptide is modified GRF(1-29), the same tetrasubstituted GHRH analog as the DAC version, without albumin conjugation.
DAC stands for Drug Affinity Complex, a maleimidopropionyl linker that bonds covalently to cysteine-34 on serum albumin, the only free thiol on the molecule.
Published clinical work on CJC-1295 with DAC reported a mean terminal half-life of roughly 5.8 to 8.1 days and IGF-I elevation lasting about 9 to 11 days after one administration.
The no-DAC form produces a discrete GH pulse; the DAC form produces a multi-day plateau, and that distinction drives study design more than any potency difference.
Mass spectrometry on a batch-specific certificate of analysis is the only practical way to confirm that a vial labelled DAC actually contains the conjugate.
Neither form is an FDA-approved drug, and both are supplied strictly for laboratory research use.

We field this question constantly from labs placing a first order. Most catalogs list both forms under the same three-character name and leave the buyer to reverse-engineer which one the paper they're replicating actually used.

What is the difference between a CJC-1295 No DAC research peptide and CJC-1295 with DAC?

CJC-1295 No DAC is modified GRF(1-29), a growth hormone-releasing hormone analog cleared within hours. The DAC version carries a maleimidopropionyl linker that bonds covalently to cysteine-34 on serum albumin, extending reported half-life to roughly 5.8 to 8.1 days. One form produces a discrete pulse. The other produces a plateau.

The common misread is that the no-DAC form is the weaker product. It isn't weaker at the receptor. Both bind the same GHRH receptor (GHRHR) on pituitary somatotrophs, both share the same tetrasubstituted backbone, and they differ only in how long they stay available to bind it. This article covers the chemistry of the DAC linker, how each form shows up in the research literature and in study design, and what documentation a research vial should ship with.

What the DAC linker actually is

DAC stands for Drug Affinity Complex, and it is a bioconjugation strategy, not a different active sequence. A maleimidopropionyl group attached near the C-terminal end of the peptide reacts with the free thiol of cysteine-34, the only unpaired cysteine on human serum albumin, forming a stable covalent adduct. Albumin is recycled through the neonatal Fc receptor (FcRn) pathway and persists in circulation for roughly three weeks, so the conjugated peptide travels with its carrier instead of being filtered or degraded on a peptide timescale.

The shared backbone matters just as much. CJC-1295 is a tetrasubstituted analog of GRF(1-29), the first 29 amino acids of human GHRH, carrying substitutions at positions 2, 8, 15 and 27. The position-2 substitution blocks dipeptidyl peptidase-4 (DPP-4), the enzyme that clips native GHRH within minutes of release. The others reduce trypsin-like cleavage and asparagine rearrangement during storage in solution. That is why a CJC-1295 No DAC research peptide, commonly catalogued as Mod GRF 1-29, already outlasts sermorelin, which is unmodified GRF(1-29), even before any albumin binding enters the picture.

In our experience fielding technical questions, this is the point that reframes the whole comparison for most buyers: no-DAC is not CJC-1295 with something missing. It is the same protected analog without the carrier.

Pulse versus plateau, and why it decides the study design

Endogenous growth hormone is released in pulses, driven by GHRH surges against a background of somatostatin tone. A short-acting GHRH analog reproduces that episodic pattern; a long-acting one does not. That single distinction drives most of the split in the literature between CJC-1295 no DAC research work and CJC-1295 with DAC research work.

The no-DAC form is the tool of choice when the question involves acute, time-resolved secretion, receptor desensitization across repeated stimuli, or synergy with a growth hormone secretagogue such as ipamorelin, which acts on a separate receptor (GHS-R1a) rather than GHRHR. The DAC form is used when the experimental variable is sustained exposure. Published clinical work on CJC-1295 with DAC reports multi-day elevation of GH and IGF-I from infrequent single administrations, and also reports that pituitary release remained pulsatile despite near-continuous receptor stimulation, which is a genuinely interesting finding rather than a footnote.

Here is the mistake we see most often, and it is not a purchasing mistake. A lab runs no-DAC material, draws a single sample at a fixed late timepoint, measures something close to baseline, and concludes the vial is inert. It usually isn't. Sampling a short-half-life GHRH analog on a schedule designed for a long-acting one measures the tail, not the response. Time-course sampling is the difference between a clean curve and a false null. Research suggests the two forms are not interchangeable inputs into the same protocol, and the assay schedule is where that becomes obvious.

Reading a vial before you trust it

A research-grade vial is only as credible as its paperwork. What we'd expect any serious supplier to provide is a batch-specific certificate of analysis showing RP-HPLC purity and mass spectrometry confirming the molecular weight matches the intended sequence, because a mass spec trace is what distinguishes genuine CJC-1295 with DAC from unconjugated peptide sold under the DAC label. Listings marketed loosely as 'cjc 1295 research chem' with no documentation attached are, functionally, unidentified material.

Handling is the second half. These compounds ship as lyophilized powder, and lyophilized peptide is far more tolerant of transit than peptide in solution. Once reconstituted, the material belongs in refrigerated storage, protected from light, with freeze-thaw cycling avoided entirely. The public literature does not specify a universal temperature-excursion threshold for either CJC-1295 form, so the honest answer is that a documented cold chain and a current certificate matter more than any number we could quote you.

Everything above is research education. These compounds are not FDA-approved drugs, they are supplied for laboratory research only, and nothing here is administration guidance for a person or an animal. Anyone with a health question about a pet should talk to their veterinarian, and anyone with a question about their own health should talk to a licensed physician.

Our CJC-1295 No DAC 10mg vial ships with its batch documentation, and the full set of analytical reports lives on our certificates of analysis page. Labs building broader secretagogue work often compare it against our growth hormone secretagogue range, the Tesamorelin and Ipamorelin research stack, or the wider growth factor and tissue signaling collection.

CJC-1295 No DAC research peptide and the DAC form, side by side

This table maps the two forms against the attributes that actually change a protocol. Structure and receptor target are shared; everything downstream of the linker is not.

Attribute	CJC-1295 No DAC (Mod GRF 1-29)	CJC-1295 with DAC	Bottom line for study design
Structure	Tetrasubstituted GRF(1-29) analog, no carrier conjugation	Same analog plus a maleimidopropionyl linker that binds albumin Cys34	The active sequence is identical; the linker is the only variable
Circulating persistence	Cleared within hours; DPP-4 resistant but not carrier-bound	Mean terminal half-life reported at roughly 5.8 to 8.1 days in healthy adults	Choose no-DAC for acute work, DAC when multi-day exposure is the variable
Secretion pattern reported	Discrete, episodic GH pulse closer to physiological rhythm	Sustained elevation of GH and IGF-I, with pulsatility still reported	Pulse versus plateau is the real decision, not which is stronger
IGF-I response in the literature	Short-lived, tracks the individual pulse	Elevated for approximately 9 to 11 days after a single administration	DAC data is far better characterized in published human pharmacokinetics
Administration frequency in published studies	Study designs use frequent, closely spaced administrations	Clinical investigation used infrequent, widely spaced single administrations	Replicating a paper requires matching its interval exactly
Assay and sampling implications	Requires time-course sampling; fixed late timepoints miss the response	Tolerates spaced sampling across days	Most false negatives with no-DAC material trace back to the sampling window
Documentation to demand	Batch COA with HPLC purity and mass spec	Same, plus mass spec confirming the conjugate, not the bare peptide	Without a mass trace, a DAC label is a claim, not a specification

What If: Research Scenarios With CJC-1295 Material

What if the paper I'm replicating just says CJC-1295 with no qualifier?

Read the methods section for administration interval before assuming either form. Papers using widely spaced single administrations across days are almost always describing the DAC conjugate, while designs with frequent closely spaced administrations point to modified GRF 1-29. If the interval is ambiguous, the sampling schedule usually settles it: hour-scale sampling windows indicate no-DAC work.

What if my CJC-1295 No DAC research peptide produced no measurable GH response?

Check the sampling timeline before replacing the vial. A short-acting GHRH analog produces a response that rises and falls on an hours-long timescale, so a single draw taken well after the pulse measures baseline regardless of how good the material is. Re-run with time-course sampling across the early window. If a full curve still shows nothing, then pull the certificate of analysis and compare the mass spec trace against the expected molecular weight.

What if a CJC-1295 research vial arrives warm?

Document the excursion and contact the supplier before use. Lyophilized powder is substantially more robust to short ambient exposure than reconstituted solution, which is why these compounds ship dry, but the published literature does not specify a validated excursion threshold for either CJC-1295 form. A supplier who can produce batch documentation and shipping validation is the only meaningful check available.

What if a listing is priced far below everything comparable?

Treat the price gap as a documentation question, not a bargain. Synthesis of a conjugated peptide carries real cost that unconjugated material does not, so DAC-labelled product priced like plain GRF(1-29) is a signal worth investigating. Ask for the batch certificate with the HPLC trace and the mass spec result; if neither exists, the discount is explained.

The unglamorous truth about choosing between the two forms

Here's the honest answer: for most study designs, the choice is decided by your endpoint and your sampling capacity, not by which form is better. If the question is acute secretion dynamics, receptor responsiveness across repeated stimuli, or interaction with a GHS-R1a agonist, the no-DAC form is the correct tool and the DAC form will blur exactly what you're trying to measure. If the question involves sustained IGF-I exposure over days, the reverse is true. Anyone selling one form as an upgrade over the other is describing a catalog, not a mechanism.

A CJC-1295 No DAC research peptide and its DAC counterpart are the same pharmacophore wearing different clocks. That framing is worth holding onto, because nearly every confused purchase, failed assay and misread paper in this corner of the literature comes from treating a pharmacokinetic difference as a potency difference. The linker didn't make the molecule stronger. It made it slower to leave. Once a protocol is built around that one fact, the rest of the decision tends to make itself.

References

Peer-reviewed sources on CJC-1295 indexed in PubMed, listed for research context. Real Peptides supplies CJC-1295 for laboratory research use only.

Netnography of Female Use of the Synthetic Growth Hormone CJC-1295: Pulses and Potions. Substance use & misuse, 2016. PMID 26771670. doi:10.3109/10826084.2015.1082595
Identification of CJC-1295, a growth-hormone-releasing peptide, in an unknown pharmaceutical preparation. Drug testing and analysis, 2010. PMID 21204297. doi:10.1002/dta.233
Activation of the GH/IGF-1 axis by CJC-1295, a long-acting GHRH analog, results in serum protein profile changes in normal adult subjects. Growth hormone & IGF research : official journal of the Growth Hormone Research Society and the International IGF Research Society, 2009. PMID 19386527. doi:10.1016/j.ghir.2009.03.001
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. The Journal of clinical endocrinology and metabolism, 2006. PMID 16352683. doi:10.1210/jc.2005-1536
Once-daily administration of CJC-1295, a long-acting growth hormone-releasing hormone (GHRH) analog, normalizes growth in the GHRH knockout mouse. American journal of physiology. Endocrinology and metabolism, 2006. PMID 16822960. doi:10.1152/ajpendo.00201.2006
Pulsatile secretion of growth hormone (GH) persists during continuous stimulation by CJC-1295, a long-acting GH-releasing hormone analog. The Journal of clinical endocrinology and metabolism, 2006. PMID 17018654. doi:10.1210/jc.2006-1702
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. PMID 15817669. doi:10.1210/en.2004-1286

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Questions

Both are tetrasubstituted GRF(1-29) analogs that bind the same GHRH receptor, so the active sequence is identical. The DAC version adds a maleimidopropionyl linker that bonds covalently to cysteine-34 on serum albumin, extending reported half-life to roughly 5.8 to 8.1 days in published human data. The no-DAC form has no carrier and clears within hours, producing a discrete pulse rather than a multi-day plateau.

A CJC-1295 No DAC research peptide binds the growth hormone-releasing hormone receptor (GHRHR) on pituitary somatotrophs, the same target as endogenous GHRH. Its four amino-acid substitutions, at positions 2, 8, 15 and 27, protect it from dipeptidyl peptidase-4 (DPP-4), the enzyme that degrades native GHRH within minutes. Without albumin conjugation, the resulting signal is short-lived and episodic.

Yes, the two names describe the same compound. Mod GRF 1-29 is the more precise chemical description: modified growth hormone-releasing factor, amino acids 1 through 29, with four stabilising substitutions. Catalog listings use 'CJC-1295 no DAC' because it signals the relationship to the DAC conjugate, which is what most buyers are comparing against.

A CJC-1295 No DAC research peptide is sold to researchers and laboratories for in-vitro and laboratory research use only. It is not an FDA-approved drug and is never supplied for human or veterinary consumption. Buyers are expected to hold appropriate institutional or professional research standing and to handle the material under their own laboratory controls.

Pricing varies widely by supplier, vial quantity and the depth of analytical documentation, so any single figure would be misleading. What matters more than price is whether the vial ships with a batch-specific certificate of analysis showing RP-HPLC purity and a mass spectrometry result confirming the molecular weight. A DAC-labelled vial without a mass trace confirming conjugation is an unverified claim.

Both forms ship as lyophilized powder, which is markedly more stable than peptide in solution. Standard laboratory practice keeps lyophilized material frozen and protected from light, and moves reconstituted solution into refrigerated storage with freeze-thaw cycling avoided. The public literature does not define a validated temperature-excursion limit for CJC-1295 specifically, so supplier cold-chain documentation is the practical reference point.

The two compounds act on different receptors. CJC-1295 is a GHRH analog acting at GHRHR, while ipamorelin is a growth hormone secretagogue acting at GHS-R1a, the ghrelin receptor. Study designs that combine them are typically investigating whether stimulating both pathways produces a greater or differently shaped secretory response than either input alone.

Published clinical investigation of the DAC conjugate used infrequent, widely spaced single administrations rather than daily ones, which reflects its multi-day half-life. Study designs using the no-DAC form use far more frequent, closely spaced administrations because the compound clears within hours. Real Peptides does not publish administration quantities or schedules for any catalog compound; replicating a published design means following that paper's own methods section.

'Research chem' is marketplace shorthand with no regulatory or analytical meaning attached to it. Research grade, used properly, implies documented synthesis with batch-level purity and identity testing. If a listing uses the first term and cannot produce an HPLC trace and mass spectrometry result for the specific batch, the material should be treated as unidentified.

No. These compounds are supplied for laboratory research use only and are not for human or veterinary consumption. Anyone with a health concern about an animal should talk to their veterinarian rather than sourcing a research compound.

The most common cause is a sampling window mismatched to the compound's kinetics. A short-acting GHRH analog produces a rise and fall across hours, so a single late draw can land entirely in the tail and read as baseline. Re-running with time-course sampling across the early window usually resolves it; if a full curve is still flat, the batch certificate of analysis is the next check.

Yes. Every catalog compound, including CJC-1295 No DAC, is synthesised in small batches with exact amino-acid sequencing and ships with batch documentation. Current analytical reports are published on the certificates of analysis page so labs can verify purity and identity before ordering rather than after.

RESEARCH USE ONLY · NOT EVALUATED BY THE FDA