CJC-1295 With and Without DAC: Two Molecules, One Name

For laboratory research use only. Not for human or veterinary use.

Three products in our catalogue carry the name CJC-1295, and the name covers two different molecules. One has an extra lysine and a reactive chemical group that lets it bind to albumin in the blood. The other does not. They differ in mass by 279 units, they behave very differently, and almost all of the published research is about only one of them. This guide sets out what each molecule is, where the name came from, what the research covers, and how to tell the two apart on a certificate.

Identity#

The sequence of the molecule without DAC is Tyr-D-Ala-Asp-Ala-Ile-Phe-Thr-Gln-Ser-Tyr-Arg-Lys-Val-Leu-Ala-Gln-Leu-Ser-Ala-Arg-Lys-Leu-Leu-Gln-Asp-Ile-Leu-Ser-Arg-NH₂. The DAC version is the same 29 residues with a lysine added at position 30, carrying the albumin-binding group on its side chain. The masses are our own calculation from the formulas.

The parent: the first 29 residues of GHRH#

Both molecules are built on growth hormone-releasing hormone (GHRH), the 44-residue hypothalamic peptide that tells the pituitary to release growth hormone. Its first 29 residues, known as GRF(1-29), keep the activity of the whole peptide, and that shorter fragment is the starting point for most synthetic analogues. Unmodified, it is sermorelin, which we also stock.

The problem with natural GHRH is how quickly it is broken down. In 1986, Lawrence Frohman and colleagues found that an enzyme in human plasma cuts the first two residues off the front of the peptide. In plasma in the laboratory, intact GHRH disappeared with a half-life of 17 minutes. In volunteers given it into a vein, the half-life was 6.8 minutes. The shortened product, missing those two residues, had less than a thousandth of the original activity. The enzyme responsible is now known as DPP-4.

Everything that follows is an attempt to solve that problem.

The four substitutions#

Both forms of CJC-1295 share the same four changes to GRF(1-29):

The result is a peptide with no methionine at all, which removes one of the commonest ways a GHRH analogue degrades on the shelf. That is the whole of the molecule sold as “CJC-1295 without DAC”.

What the DAC is#

DAC stands for Drug Affinity Complex, a name used by the Montreal company ConjuChem for its technology. The chemistry is specific. A lysine is added to the end of the peptide, and a maleimidopropionyl group is attached to the lysine’s side chain. A maleimide reacts quickly and selectively with a free thiol. Human serum albumin, the most abundant protein in blood, carries exactly one free thiol, on the cysteine at position 34. Once the peptide is in circulation, it bonds covalently to albumin and travels with it, and albumin is cleared slowly.

ConjuChem’s 2005 paper describes the selection. The company made three maleimide versions of GRF(1-29) and bonded each to human albumin in the laboratory. All three resisted DPP-4 better than the unbound peptide and still released growth hormone from cultured rat pituitary cells. Given to rats, the best of the three produced four times the growth hormone response of plain GRF(1-29) over two hours, and was still present in plasma beyond 72 hours. A blot of rat plasma showed it on the albumin band from 15 minutes onwards. That compound was named CJC-1295.

Where the name went wrong#

By the developer’s own description, CJC-1295 is the tetrasubstituted GRF(1-29) with the maleimide lysine. The code belonged to the DAC molecule. “CJC-1295 without DAC” describes a different molecule by subtracting a feature from this one, and it is properly called modified GRF(1-29).

The market settled the matter the other way. In 2009, the Norwegian anti-doping laboratory analysed an unknown preparation for the police and customs. It contained a 29-residue peptide with an amidated end, consistent with a peptide sold under the name CJC-1295. That is the molecule without DAC. By 2016, a German anti-doping paper was defining CJC-1295 in its introduction by the four substitutions alone, with no DAC at all.

So the name is used both ways, in the trade and in the literature. When a paper or a product listing says CJC-1295, check which molecule it means before carrying any finding across. The trade has settled on “with DAC” and “without DAC”, and we use those names.

What the research covers#

Almost all of the published research on CJC-1295 is on the DAC molecule. We count four core papers:

• 2005, rats. The selection paper described above.
• 2006, healthy adults. Two randomised, placebo-controlled, double-blind studies at ascending levels, lasting 28 and 49 days, in people aged 21 to 61. After a single administration, mean growth hormone rose two- to ten-fold for six days or more, and IGF-1 rose 1.5- to three-fold for 9 to 11 days. The estimated half-life was 5.8 to 8.1 days. After repeated administration, IGF-1 stayed above baseline for up to 28 days. No serious adverse reactions were reported.
• 2006, the pulse question. A long-acting stimulus might be expected to flatten the natural on-off pattern of growth hormone release. A University of Illinois study sampled blood every 20 minutes overnight in healthy men aged 20 to 40, before and one week after a single administration. The pulses were preserved, with their frequency and size unchanged. What changed was the floor between them: trough growth hormone rose 7.5-fold, mean growth hormone by 46% and IGF-1 by 45%. The two levels tested gave no significant difference.
• 2006, mice. In mice lacking the GHRH gene, given CJC-1295 from one week old for five weeks, administration every 24 hours produced normal body weight and length. Every 48 or 72 hours did better than placebo but did not fully normalise growth. Pituitary growth hormone RNA rose, and the pituitary cells that make growth hormone multiplied.

For the molecule without DAC, the published picture is much thinner. What we have found is mostly anti-doping chemistry: methods for detecting it, rather than studies of what it does. Findings from the DAC studies, the multi-day half-life above all, do not transfer to it. Without albumin binding it is cleared far faster.

The trial that stopped#

In 2006, ConjuChem was running a phase 2 trial of the DAC molecule in 192 people with HIV-associated abdominal fat, given weekly for twelve weeks. In July 2006 a participant at a site in Argentina had a heart attack about two hours after his eleventh administration, and died. ConjuChem halted the trial (aidsmap report). The company’s later statement gave the cause of death; we have not found a published conclusion on whether the compound played a part.

CJC-1295 did not go on to become a medicine. It is not licensed anywhere, in either form.

Anti-doping status#

GHRH and its analogues are on the World Anti-Doping Agency Prohibited List, and the 2010 Norwegian paper names CJC-1295 as prohibited under section S2. Anti-doping laboratories have published methods for detecting it in plasma. Anyone subject to anti-doping testing should not handle either form. As with ipamorelin and AICAR, this is a plain fact about the compound and belongs on the page.

What to check on the certificate#

• Which molecule it is. 3647.2 with DAC, 3367.9 without. The gap of about 279 is the lysine (about 128) plus the maleimidopropionyl group (about 151). A certificate for material sold “with DAC” that reports a mass near 3368 is describing the other compound.
• What the spectrum shows. Peptides this size appear as several charged ions. With DAC, expect peaks near 1216.0 (triply charged) and 912.3 (quadruply). Without DAC, near 1123.0 and 842.5, and often 674.2 (five charges).
• Not sermorelin. Plain GRF(1-29) weighs 3357.9, only about 10 units below the molecule without DAC. A certificate that rounds to “about 3360” cannot tell them apart. The triply charged ions sit at 1119.6 for sermorelin and 1123.0 for modified GRF(1-29), which any properly reported spectrum separates.
• A spent maleimide. The maleimide on the DAC version can react with water and ring-open, which adds 18 (a peak near 3665). A ring-opened maleimide can no longer bind albumin, so the molecule has the right sequence but has lost the feature it is sold for.
• Net peptide content and counter-ion. Both forms have five basic residues (three arginines and two lysines) plus the free amino end, so each can carry up to six counter-ions. Net peptide content is how much of the powder is peptide, and it is not the same number as purity.
• Purity, with the method named, measured on that batch.

Ask about the documentation for the batch we would ship before you order. See also how to read a COA, how much is actually in the vial and what a purity figure means.

Handling and storage#

Standard peptide handling applies to both. Store the sealed lyophilised vial cold, dry and out of light, and let it reach room temperature before opening so moisture does not condense inside. Reconstitute by running bacteriostatic or sterile water down the vial wall rather than onto the powder, and swirl rather than shake. Once in solution, keep it refrigerated. The DAC version needs one extra precaution: keep it away from buffers and additives that contain thiols, which will react with the maleimide and use it up. The reconstitution guide, solvent guide and storage guide cover the detail.

What Pioneer supplies#

CJC-1295 with DAC is stocked in a 5mg vial. CJC-1295 without DAC is stocked in 5mg and 10mg vials, with a 2mg vial made to order in one to two weeks. It is also supplied pre-blended with ipamorelin, and our ipamorelin guide covers the other half of that blend. Sermorelin, the unmodified parent fragment, is stocked as well.

Quality comes first#

Two molecules share one name, a third sits only 10 mass units from one of them, and the feature that defines the DAC version can be lost to water without changing the sequence. The mass on the certificate is what separates all of these. Ask about the documentation for the batch we would ship before you order.

Sources#

Each entry links to its PubMed record, where the title and abstract can be read. The descriptions are ours: they say what each paper examined, not what it is claimed to show. Records checked on PubMed on 31 October 2026.

1. Frohman LA, Downs TR, Williams TC, et al. (1986). J Clin Invest 78(4):906–13. Breakdown of natural GHRH in human plasma and in volunteers: removal of the first two residues by a plasma enzyme, and the activity of the shortened product. PubMed 3093533
2. Jetté L, Léger R, Thibaudeau K, et al. (2005). Endocrinology 146(7):3052–8. The developer's description of three albumin-binding GRF(1-29) derivatives, and the selection of CJC-1295 from them, in rat pituitary cells and rats. PubMed 15817669
3. Teichman SL, Neale A, Lawrence B, et al. (2006). J Clin Endocrinol Metab 91(3):799–805. Two randomised, placebo-controlled studies in healthy adults measuring the half-life of the DAC molecule and growth hormone and IGF-1 levels over several weeks. PubMed 16352683
4. Ionescu M, Frohman LA. (2006). J Clin Endocrinol Metab 91(12):4792–7. Overnight sampling every 20 minutes in healthy men, before and one week after the DAC molecule, examining whether growth hormone pulses were preserved. PubMed 17018654
5. Alba M, Fintini D, Sagazio A, et al. (2006). Am J Physiol Endocrinol Metab 291(6):E1290–4. Mice lacking the GHRH gene given the DAC molecule at three different intervals for five weeks, measuring growth and pituitary changes. PubMed 16822960
6. Henninge J, Pepaj M, Hullstein I, Hemmersbach P. (2010). Drug Test Anal 2(11-12):647–50. Norwegian anti-doping laboratory analysis of a seized preparation, which contained a 29-residue peptide sold under the name CJC-1295. PubMed 21204297
7. Knoop A, Thomas A, Fichant E, et al. (2016). Anal Bioanal Chem 408(12):3145–53. A validated anti-doping method for detecting several GHRH analogues, CJC-1295 among them, in plasma. PubMed 26879649

Both forms, in our catalogue#

• CJC-1295 (with DAC) — the albumin-binding form; 5mg in stock
• CJC-1295 (without DAC) — modified GRF(1-29); 5mg and 10mg in stock, 2mg made to order
• CJC-1295 (without DAC) + Ipamorelin — without DAC, pre-blended with ipamorelin
• Sermorelin Acetate — the unmodified GRF(1-29) parent

Pioneer Research Peptides — UK supplier of research peptides for laboratory use. Ask about batch documentation before you order.

For laboratory research use only — not for human consumption. 18+.