CJC-1295 DAC: The Long-Acting GHRH Analog and What the Research Shows

CJC-1295 DAC: The Long-Acting GHRH Analog and What the Research Shows

By Medical Team of Generic Peptides

Quick answer. CJC-1295 DAC is a synthetic analog of growth hormone–releasing hormone (GHRH) built to last. A reactive chemical group lets it attach to albumin in the blood, and in healthy adults that gave it an estimated half-life of 5.8–8.1 days. Most of what is known about CJC-1295 with DAC comes from a handful of rat, mouse and human studies published in 2005–2006, after which its clinical development stopped. It is not approved as a drug anywhere and is prohibited in sport.

What Is CJC-1295 DAC?

CJC-1295 DAC starts from GRF(1-29), the first 29 amino acids of human GHRH, which carry the hormone's full activity at its receptor on the pituitary. Four of those amino acids are replaced to protect the peptide from enzymes in the blood, and a lysine carrying a maleimidopropionyl group is added at the end [1]. That last addition is the "DAC" — Drug Affinity Complex, the developer's name for the technology.

The finished molecule has the formula C165H269N47O46 and a molecular weight of about 3,647 Da (CAS 446262-90-4) [8]. It was developed by the Canadian company ConjuChem, which also published most of the early research on it.

A note on names: in the original literature, "CJC-1295" always meant the DAC version. The shorter-acting peptide sold as "CJC-1295 no DAC" is Modified GRF (1-29), a related but different molecule. We compare the two in detail in CJC-1295 DAC vs No DAC.

How DAC Works: Albumin Binding

Native GRF(1-29) is cut by the enzyme dipeptidyl peptidase-4 within minutes of entering the blood. The CJC-1295 DAC design attacks that problem twice: the amino acid substitutions resist the enzyme, and the DAC group ties the peptide to the most abundant protein in plasma.

The 2005 study that introduced CJC-1295 showed how this works [1]:

• The maleimide group reacts with the free thiol on cysteine-34 of serum albumin, forming a covalent bond.
• In rats, the peptide appeared on the albumin band within 15 minutes and remained in circulation beyond 24 hours; it was still detectable in plasma beyond 72 hours.
• Over two hours, CJC-1295 produced a GH response about four times larger (by area under the curve) than unmodified GRF(1-29).
• The albumin-bound form still activated GRF receptors on cultured rat pituitary cells.

Albumin circulates for weeks and is too large to be filtered by the kidneys, which is why a peptide riding on it lasts so much longer than a free one.

CJC-1295 DAC Half-Life and GH Response in Humans

Two studies from 2006 are the core of the human data on CJC-1295 with DAC.

Healthy adults, single and repeated administration. Two randomized, placebo-controlled, double-blind trials in healthy volunteers aged 21–61 lasted 28 and 49 days [2]. After a single administration:

• mean GH rose 2- to 10-fold, depending on dose, and stayed elevated for 6 days or more;
• mean IGF-1 rose 1.5- to 3-fold for 9–11 days;
• the estimated half-life was 5.8–8.1 days.

With repeated administration, mean IGF-1 stayed above baseline for up to 28 days. No serious adverse reactions were reported.

What happens to natural GH pulses. A second study sampled blood every 20 minutes overnight in healthy men aged 20–40, before and one week after a single injection [3]. The number and size of GH pulses did not change. Trough GH levels — the baseline between pulses — rose 7.5-fold, overall mean GH rose 46%, and IGF-1 rose 45%. The IGF-1 increase did not correlate with any measure of GH secretion.

Together, these studies answer the common question of how long CJC-1295 DAC acts: in healthy adults, hormone levels stayed elevated for roughly one to two weeks after a single administration. They did not measure body composition, strength, sleep or any other clinical outcome.

CJC-1295 With DAC in Animal Research

The most cited animal study tested CJC-1295 in mice that lack their own GHRH, a model of GH deficiency [4]. Young knockout mice were treated for five weeks at three different intervals:

• every 24 hours: body weight and length normalized, and femur and tibia length stayed normal;
• every 48 or 72 hours: growth improved compared with placebo, but did not fully normalize;
• all treated groups: relative lean mass and subcutaneous fat mass were normal.

The treated mice also showed more pituitary GH messenger RNA and signs of somatotroph proliferation, suggesting the analog stimulated growth of GH-producing cells. These dosing intervals describe a mouse study; they are not a guide to human use.

CJC-1295 DAC Studies at a Glance

The Clinical Program and Why It Stopped

ConjuChem took CJC-1295 into a 12-week Phase 2 trial in people with HIV-associated visceral obesity, registered as NCT00267527 and started in December 2005 [5]. In July 2006 the company stopped the study after a participant died [6]. Public reports did not establish the cause of death or any link to the drug, and the trial is listed as terminated. CJC-1295 was not taken back into clinical development.

As a result, the human evidence for CJC-1295 with DAC ends with short pharmacokinetic studies in healthy volunteers. A 2026 review in Frontiers in Endocrinology noted that neither CJC-1295 form has been approved by the FDA or the European Medicines Agency [7].

CJC-1295 DAC Safety Findings

What is known about safety comes from three sources:

• Human studies. The 2006 trials in healthy adults reported no serious adverse reactions over 28–49 days [2]. They were too small and too short to detect rare or long-term effects.
• The halted Phase 2 trial. One participant died; the cause was not established publicly [6].
• The FDA's 2024 review. For its Pharmacy Compounding Advisory Committee, the FDA reviewed CJC-1295 and its DAC forms. Its main stated concern was immunogenicity — the possibility that the peptide, impurities or aggregates provoke an immune response, especially when injected — and it described dose-dependent injection-site irritation in repeat-dose dog studies [10, 11].

Sustained elevation of IGF-1 is also a general consideration with any long-acting GH-axis stimulant, but no long-term data exist for CJC-1295 DAC specifically.

CJC-1295 DAC vs No DAC

The short version: both share the same tetrasubstituted GRF(1-29) backbone, but only CJC-1295 DAC binds albumin. That is why it has days-long human pharmacokinetic data, while the no-DAC peptide (Mod GRF 1-29) has essentially none. For a full table of structure, mass, half-life and evidence, see CJC-1295 DAC vs No DAC: Half-Life and Research, and for the short-acting form, our Mod GRF 1-29 research guide.

CJC-1295 DAC FDA and WADA Status

Checked October 24, 2026.

FDA. CJC-1295 with DAC is not an FDA-approved drug. CJC-1295 and its DAC forms were previously listed in Category 2 of the FDA's interim policy on 503A bulk drug substances. They were removed from Category 2 effective September 27, 2024, after the nominations were withdrawn, and referred to the Pharmacy Compounding Advisory Committee [9, 12]. On December 4, 2024, the committee voted against adding any form to the 503A bulks list — 0 to 13 for CJC-1295 DAC free base, DAC acetate and DAC trifluoroacetate [11]. CJC-1295 was not on the agenda of the July 2026 advisory meeting. For the latest policy developments, see our report on the FDA's interim access policy for peptides.

WADA. The 2026 Prohibited List names CJC-1295 under S2.2.4, growth hormone–releasing factors, together with sermorelin and tesamorelin [13]. It is prohibited at all times. Related GHRH analogs are covered in our guides to sermorelin and tesamorelin.

Verifying CJC-1295 DAC on a COA

The albumin-binding group is the most demanding part of CJC-1295 DAC to make, and it is also the part a label cannot prove. A certificate of analysis should include:

• Mass spectrometry showing a mass of about 3,647 Da. A result near 3,368 Da means the vial contains the no-DAC peptide instead.
• HPLC purity for the same lot.
• A lot number that matches the vial.

Our guide on how to read a research peptide COA explains each section. Generic Peptides supplies CJC-1295 DAC for laboratory research with a lot-specific COA; it is listed in our Growth Hormone & IGF-1 category.

FAQ

What is CJC-1295 DAC?

A synthetic GHRH analog — tetrasubstituted GRF(1-29) plus an albumin-binding group — that stimulates the pituitary to release growth hormone. The DAC group extends its half-life to several days.

What is the half-life of CJC-1295 with DAC?

In healthy adults, the estimated half-life was 5.8–8.1 days [2].

How long does CJC-1295 with DAC raise GH and IGF-1?

In the 2006 human study, a single administration raised GH for 6 days or more and IGF-1 for 9–11 days; with repeated administration, IGF-1 stayed above baseline for up to 28 days.

How often was CJC-1295 DAC given in studies?

In GHRH-knockout mice it was given every 24, 48 or 72 hours for five weeks; daily treatment normalized growth. Human studies tested single and repeated administration in healthy volunteers. There is no approved human dose.

Is CJC-1295 DAC legal?

It is not an FDA-approved drug and cannot be compounded by 503A pharmacies. It is prohibited in sport under WADA S2.2.4. It is sold only as a research compound for laboratory use.

References

For research use only. Not for human consumption. This content is for informational purposes and is not medical advice.