What is CJC-1295 with DAC?

Compound Spotlight

CJC-1295 with DAC is a growth hormone releasing hormone (GHRH) analogue built to do one thing native GHRH cannot: stay in circulation for days. It does that by attaching itself to serum albumin after injection. The catch is the name. “CJC-1295” is also used for a 29-residue peptide that lacks the albumin-binding chemistry entirely, and the two behave very differently.

Where it comes from

GHRH is the hypothalamic signal that tells the pituitary to release growth hormone. Its N-terminal fragment, GHRH(1-29), is the basis for analogues such as sermorelin and CJC-1295. The problem with all of them is clearance: GHRH has a very short half-life, which limits how long any single dose acts.

ConjuChem’s approach was to let the body’s own albumin act as a carrier. In a 2005 paper, Jetté and colleagues described three maleimide-bearing derivatives of GRF(1-29), bioconjugated to albumin. All three resisted dipeptidyl peptidase-IV in vitro and stimulated GH release from cultured rat pituitary cells. The best performer, named CJC-1295, produced a 4-fold larger GH response than unmodified GRF(1-29) in rats over two hours and was still detectable in rat plasma beyond 72 hours.

What “DAC” actually is

Structurally, CJC-1295 is GRF(1-29) with four amino acid substitutions, plus an extra lysine at the C-terminus carrying a maleimidopropionamide group. That reactive group is the Drug Affinity Complex. After injection it forms a covalent bond with the free thiol on cysteine-34 of serum albumin. In the rat work, CJC-1295 immunoreactivity showed up on the albumin band within 15 minutes and remained beyond 24 hours.

Once attached, the peptide circulates with albumin. That is the whole trick: the peptide sequence still acts on the GHRH receptor, but its time in circulation is now tied to the protein it is attached to.

With DAC vs. without DAC

This is where most of the confusion lives. Two different molecules are sold under nearly the same name:

• CJC-1295 with DAC is the compound ConjuChem developed and tested. It carries the extra lysine and the albumin-reactive group. All of the published human pharmacokinetic data, including the multi-day half-life, describe this form.
• CJC-1295 without DAC, commonly labelled “Mod GRF (1-29)”, is a 29-residue peptide with a C-terminal amide and no albumin-binding group. Without that group it has no mechanism for latching onto albumin, so the week-scale half-life does not apply to it. Expect it to behave like other short-acting GHRH(1-29) analogues, not like the DAC form.

When the Norwegian doping control laboratory analysed a seized preparation in 2009, it found a 29-amino-acid amidated peptide and noted that the sequence matched a product “marketed under the name CJC-1295”. An anti-doping study from King’s College London in 2021 treated “CJC-1295” and “CJC-1295 with drug affinity complex” as two separate analytes for the same reason.

The practical upshot: a published study of CJC-1295 is a study of the DAC form, and its findings should not be transferred to the no-DAC peptide. The two differ in the very property CJC-1295 was designed around.

What the human studies examined

Teichman and colleagues (2006) ran two randomized, placebo-controlled, ascending-dose trials in healthy adults aged 21 to 61. After a single injection, mean GH rose 2- to 10-fold for six days or more and IGF-I rose 1.5- to 3-fold for 9 to 11 days, in a dose-dependent manner. The estimated half-life was 5.8 to 8.1 days, and repeated doses showed a cumulative effect on IGF-I.

Ionescu and Frohman (2006) asked a more specific question: does continuous GHRH stimulation flatten the natural pulsatile rhythm of GH release? In healthy men aged 20 to 40, sampled every 20 minutes overnight before and one week after a single injection, the answer was no. Pulse frequency and size were unchanged. What changed was the baseline: trough GH rose 7.5-fold, mean GH rose 46% and IGF-I rose 45%.

In animals, Alba and colleagues (2006) gave CJC-1295 to mice lacking the GHRH gene. Daily administration over five weeks produced normal body weight and length, while less frequent administration was less effective.

What the evidence supports

The evidence for CJC-1295 with DAC is pharmacological, and it is fairly clean: rat studies establishing albumin binding, a mouse growth model, and small human studies in healthy volunteers showing that GH and IGF-I rise and stay elevated for days. A follow-up analysis of serum from 11 of those men looked for new protein markers of GH action, not clinical outcomes.

What is missing is any completed trial of clinical benefit. ConjuChem took the compound into a Phase II study in 192 people with HIV-associated visceral fat accumulation, and halted it on 17 July 2006 after a participant died. At the time, the cause of death and its relationship to the drug were under investigation. No later phase followed, and CJC-1295 has not been approved by the FDA for any use. It is a GHRH analogue and so falls under the growth hormone releasing factors prohibited in sport by WADA.

The no-DAC peptide has even less behind it. The published human studies above were not done with it.

Frequently asked questions

Is CJC-1295 the same as Mod GRF (1-29)?

No. Mod GRF (1-29) is the 29-residue peptide without the Drug Affinity Complex. CJC-1295 as developed and studied carries the DAC, which is what lets it bind albumin and persist for days. Check which one a label or a paper actually refers to.

Does a long half-life mean GH stays permanently elevated?

Not in the one study that measured it directly. Ionescu and Frohman found GH was still released in pulses of unchanged frequency and size after CJC-1295. The difference was a higher baseline between pulses.

How do I know what is actually in the vial?

Every lot we sell has a published Certificate of Analysis from an independent, third-party lab confirming identity and purity. Lot numbers on the vial should match the COA you are referencing.

References

• Jetté L, 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.
• Teichman SL, et al. 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.
• 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.
• Alba M, 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.
• Sackmann-Sala L, et al. 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 Horm IGF Res. 2009;19(6):471–477.
• Henninge J, et al. Identification of CJC-1295, a growth-hormone-releasing peptide, in an unknown pharmaceutical preparation. Drug Test Anal. 2010;2(11-12):647–650.
• Memdouh S, et al. Advances in the detection of growth hormone releasing hormone synthetic analogs. Drug Test Anal. 2021;13(11-12):1871–1887.

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For laboratory and research use only. Not for human consumption. CJC-1295 is not approved by the FDA for any use; its clinical development stopped at Phase II, and it is prohibited in competitive sport under WADA rules. This article summarizes published research for informational purposes and is not medical advice, nor a recommendation or protocol for use.

Related research compounds

Arc Peptides supplies these compounds, each third-party tested for purity and identity with a lot-specific Certificate of Analysis:

• CJC-1295 with DAC

For laboratory research use only. Not for human consumption.