Key Takeaways
- •DAC stands for Drug Affinity Complex, a reactive group that forms a covalent bond to serum albumin after administration, which is what extends the molecule's circulating half-life from minutes to days.
- •CJC-1295 is the DAC-bearing molecule: CAS 446262-90-4, formula C165H269N47O46, average mass 3647.2 g/mol.
- •"CJC-1295 without DAC" is a different compound with its own name, usually modified GRF(1-29), roughly 279 daltons lighter.
- •Both human studies used the DAC version. The 2006 papers in the Journal of Clinical Endocrinology and Metabolism measured a half-life of 5.8 to 8.1 days for CJC-1295. No comparable human study exists for the no-DAC compound.
- •Growth hormone pulsatility was preserved in the study that measured it, which contradicts the "constant bleed" claim repeated on most pages.
- •Neither is FDA-approved, and neither is in the October 2026 HHS compounding policy. FDA's own safety summary lists serious adverse events reported with CJC-1295.
CJC-1295 with DAC and CJC-1295 without DAC are sold side by side as two strengths of one idea. They are two different molecules, about 279 daltons apart, and both published human studies everybody cites were conducted on only one of them. The "no DAC" name is also a misnomer: take the DAC off CJC-1295 and what remains already has its own name, modified GRF(1-29).
This guide covers what the DAC is, what each molecule is, what the two human studies measured, where both stand with the FDA after the 2026 compounding decisions, and how to tell the two apart on a certificate. It is written for laboratory and in-vitro research procurement. It reports what published studies recorded because that is the public evidence base, and it contains no dosing, administration or human-use guidance, and none should be inferred.
What the DAC Actually Is
A 29-residue peptide injected into the bloodstream is cleared within minutes. Two things do it: peptidases cut the chain, and the kidney filters anything small enough to pass. Both problems are solved by making the molecule effectively much larger, and the cheapest way to do that is to attach it to a protein already in the blood.
The Drug Affinity Complex is a maleimide-based reactive group attached to the peptide. Maleimides react specifically with free thiols, and human serum albumin carries one accessible free cysteine, at position 34. So the conjugate finds albumin, forms a covalent bond with that cysteine, and the peptide is thereafter carried on a 66,500-dalton protein with a circulating half-life measured in days rather than minutes.
This is a pharmacokinetic device and nothing else. It does not change which receptor the peptide addresses. It changes how long the peptide remains available to address it. That is why the DAC is not an optional accessory: it is the entire reason CJC-1295 exists as a distinct compound rather than as one more GRF analogue.
The Two Molecules
| Property | CJC-1295 (with DAC) | Modified GRF(1-29) ("no DAC") |
|---|---|---|
| CAS number | 446262-90-4 | No single registry entry in common use |
| Molecular formula | C165H269N47O46 | Not established by a registry record |
| Average mass | 3647.2 g/mol | Approximately 3368 g/mol as commonly quoted |
| Monoisotopic mass | 3645.0155 Da | Not established by a registry record |
| Albumin conjugation | Yes, covalent, via a free cysteine | No |
| Measured human half-life | 5.8 to 8.1 days | Not published |
| PubChem record | CID 91971820 | None under either common name |
The figures in the left column are verified against PubChem CID 91971820. The figures in the right column are not, and that asymmetry is the most useful thing in the table.
Modified GRF(1-29) is a tetrasubstituted analogue of GRF(1-29), the same 29-residue fragment of growth hormone-releasing hormone that sermorelin is. The best characterised of its substitutions is a D-alanine at position 2, which blocks cleavage by dipeptidyl peptidase-4, the enzyme that otherwise clips the first two residues off a GHRH receptor ligand and inactivates it.
So the three compounds form a sequence rather than a set of equivalents: sermorelin is the native fragment, modified GRF(1-29) is that fragment hardened against enzymatic attack, and CJC-1295 is the hardened fragment plus an albumin anchor.
What the Two Human Studies Measured
There are two published human studies of CJC-1295, both from 2006, and both used the DAC-bearing molecule.
| Teichman et al. 2006 | Ionescu and Frohman 2006 | |
|---|---|---|
| Journal | J Clin Endocrinol Metab 91(3):799-805 | J Clin Endocrinol Metab 91(12):4792-4797 |
| Design | Two randomised, placebo-controlled, double-blind ascending-dose trials, 28 and 49 days | Overnight 12-hour sampling before and one week after a single injection |
| Participants | Healthy adults aged 21 to 61 | Healthy men aged 20 to 40 |
| Half-life | 5.8 to 8.1 days | About 8 days, as cited |
| Growth hormone | Mean levels 2- to 10-fold higher for 6 days or more | Pulsatility preserved; trough levels 7.5-fold higher; mean levels 46% higher |
| IGF-I | 1.5- to 3-fold higher for 9 to 11 days | 45% higher |
Does growth hormone still pulse?
The most repeated claim about the DAC version is that it replaces the body's natural pulses with a flat, continuous signal. The study designed to answer that question reported the opposite. Ionescu and Frohman sampled blood every 20 minutes overnight and found that "the frequency and magnitude of GH secretory pulses were unaltered" while trough levels rose sharply. Their conclusion was that CJC-1295 increased trough and mean secretion "with preserved GH pulsatility."
That does not make the compound benign or useful; it makes one common argument for the no-DAC version unsupported by the only human evidence that exists on the point.
Why the naming matters for reading the evidence
The Teichman paper's title is "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 finding is prolonged stimulation and the compound is described as long-acting. Both of those properties are the DAC. A molecule without the albumin anchor has a half-life of minutes and cannot produce prolonged stimulation, so the paper's central result does not transfer to it.
Citing that study on a page selling the non-DAC compound attributes to one molecule a result obtained with another, and the result in question is specifically the one the two molecules do not share. The rest of the literature is thin and mostly analytical: a 2026 paper in Drug Testing and Analysis reports detection of CJC-1295 in equine plasma by ELISA, which is anti-doping work, and several 2026 narrative reviews discuss it among peptides used outside clinical supervision.
Status in the United States
| Question | CJC-1295 (with DAC) | Modified GRF(1-29) |
|---|---|---|
| FDA-approved drug product | No | No |
| On the 503A Bulks List | No | No |
| In the October 2026 HHS compounding policy | No | No |
| Prohibited in competitive sport | Yes | Yes |
| Supplied as | Research material, in vitro use only | Research material, in vitro use only |
Neither compound has ever been an approved drug in the United States, and neither appears in the draft HHS enforcement discretion policy published on 30 October 2026, which covers six other peptides. FDA's published summary of substances that may present significant safety risks in compounding addresses CJC-1295 directly: it says compounded drugs containing it "may pose risk for immunogenicity for certain routes of administration" and that the agency "has identified serious adverse events associated with CJC-1295 including increased heart rate and systemic vasodilatory reaction," adding that available clinical data are limited. Both compounds fall within the World Anti-Doping Agency's prohibition on growth hormone-releasing factors and their analogues, which applies at all times.
It is worth contrasting that with the GHRH analogues that did clear the FDA. Tesamorelin holds a US approval as Egrifta. Sermorelin held an FDA approval as Geref; the FDA determined in 2013 that Geref had not been withdrawn for reasons of safety or effectiveness, which is the formal record of a commercial withdrawal rather than a safety one. Four molecules in one structural family with four different regulatory positions, compared in detail in tesamorelin vs sermorelin vs ipamorelin.
How to Tell the Two Apart on a Certificate
This is the clearest case on the shelf where a certificate can settle a question the label cannot.
The mass difference is large and unambiguous. Roughly 279 daltons separates the two molecules, about 7.6% of the total mass. A mass spectrometric identity check reporting a mass near 3647 is the DAC-bearing compound; one reporting a mass near 3368 is not. If a certificate for a product sold as one of them reports the other's mass, the vial does not contain what the label says.
Ask what the reported mass refers to. A multiply-charged species in a mass spectrum is reported at mass divided by charge, so a figure near 1216 may be the triply-charged DAC compound rather than a different molecule. A certificate should state the charge state or the method.
A purity figure cannot distinguish them at all. Both are 29-residue peptides of similar composition, and both can be synthesised to high chromatographic purity. Which molecule is in the vial is a mass spectrometry question, which is the distinction what actually proves a peptide sequence is about.
For the non-DAC compound there is no registry entry to check against. No PubChem record answers to "mod GRF 1-29" or "CJC-1295 without DAC", so the reference values a buyer would normally verify against do not exist in a public database under those names. That makes the laboratory's own reference standard and stated method the whole basis of the identity claim.
Check the three things that make a certificate checkable:
- The laboratory is named, with its report number.
- The lot number on the document matches the vial in your hand.
- The laboratory publishes a verification page where the report number can be looked up independently.
Volta publishes its certificates as page images in its published certificate archive with the issuing laboratory's own verification link, and a certificate for the batch you receive is available on request. Those reports carry both HPLC and mass spectrometry results, and the peptide testing labs directory lists independent laboratories for a second opinion.
The Two Products and the Combination Vial
Volta stocks CJC-1295 with DAC as a 5 mg vial and the no-DAC compound as a 10 mg vial, plus a 10 mg multi-component vial pairing the no-DAC compound with ipamorelin. The compound hubs are CJC-1295 DAC and CJC-1295 no-DAC.
The combination vial puts two compounds acting at two different receptors in one container. A GRF analogue addresses the GHRH receptor; ipamorelin addresses GHS-R1a, the ghrelin receptor, as set out in the ipamorelin guide. A composition certificate for such a vial measures each compound separately, as covered in the analytical tradeoffs of a blend, reporting a purity and a net peptide content per component rather than one purity for the vial.
Comparing the 5 mg DAC vial against the 10 mg no-DAC vial on milligrams alone compares two different things, since the molecules differ in mass and in measured half-life by orders of magnitude.
Frequently Asked Questions
What does DAC mean in CJC-1295?
DAC stands for Drug Affinity Complex. It is a maleimide-based reactive group attached to the peptide that forms a covalent bond with the free cysteine at position 34 of human serum albumin, so the peptide is carried on a large plasma protein instead of being cleared within minutes.
What is the difference between CJC-1295 with DAC and without DAC?
They are two different molecules. The DAC version is about 3647 g/mol, binds albumin, and had a measured half-life of 5.8 to 8.1 days in human studies. The no-DAC version is modified GRF(1-29), roughly 279 daltons lighter, with no albumin anchor and no published human half-life.
Is "CJC-1295 without DAC" a weaker CJC-1295?
No, it is a different compound with its own name. The name is a convention of the supply market rather than a chemical description.
Is mod GRF 1-29 the same as CJC-1295 no DAC?
In current supplier usage, yes, the two names refer to the same tetrasubstituted GRF(1-29) analogue. Neither name has a public registry record, which is why a certificate for it rests on the laboratory's own reference standard.
What is the half-life of CJC-1295?
The 2006 Teichman study measured 5.8 to 8.1 days for the DAC-bearing molecule. No equivalent human measurement has been published for the no-DAC compound.
Which compound were the human studies done on?
Both 2006 studies used CJC-1295 with DAC. Their central findings, prolonged stimulation and a multi-day half-life, are properties of the albumin conjugation and do not transfer to the no-DAC compound.
Does CJC-1295 with DAC stop growth hormone from pulsing?
Not according to the study that measured it. Ionescu and Frohman reported that pulse frequency and magnitude were unaltered while trough levels rose about 7.5-fold.
Is CJC-1295 FDA-approved?
No. Neither form is approved for any use, neither is on the 503A Bulks List, and neither is covered by the October 2026 HHS enforcement discretion policy. FDA's safety summary records serious adverse events reported with CJC-1295.
How does modified GRF(1-29) differ from sermorelin?
Sermorelin is the unmodified GRF(1-29) amide. Modified GRF(1-29) is a tetrasubstituted version of the same fragment, of which the best characterised substitution is a D-alanine at position 2 that blocks cleavage by dipeptidyl peptidase-4.
Can a purity figure tell the two apart?
No. Both can reach high chromatographic purity. Which molecule is in the vial is a mass spectrometry question.
Sources
- 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. PMID 16352683.
- 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. PMID 17018654.
- US Food and Drug Administration. "Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks." Content current as of 22 April 2026.
- US Department of Health and Human Services. "Enforcement Discretion Policy Regarding 503A Compounding Using Certain Peptide Bulk Drug Substances." Federal Register, 30 October 2026, FR Doc. 2026-22192.
- US Food and Drug Administration. "Determination That GEREF (Sermorelin Acetate) Injection ... Were Not Withdrawn From Sale for Reasons of Safety or Effectiveness." Federal Register, 4 March 2013, FR Doc. 2013-04827.
- PubChem Compound Summary, CID 91971820 (CJC-1295). National Library of Medicine.
- PubChem: no compound record returned for "mod GRF 1-29", "CJC-1295 without DAC" or "tetrasubstituted GRF", checked 6 November 2026.
- World Anti-Doping Agency. Prohibited List, section S2.
- "Detection of CJC-1295 in Equine Plasma by ELISA." Drug Testing and Analysis. 2026. PMID 42876013.
- "The emerging landscape of performance-enhancing peptides modulating GH-IGF1 axis." Frontiers in Endocrinology. 2026. PMID 42395176.
