CJC-1295 (Including the "No DAC" Variant): A Literature Course

This course walks through the published record on CJC-1295 in six modules: what the compound is, how its mechanism has been described, what individual studies reported, what adverse events appear in the literature, what pharmacokinetic data exist, and how the compound is treated by regulators. Each module closes with the limits of that evidence. This page is for educational purposes only and is not medical advice; consult a licensed physician about any medical question or decision.

Module 1 — What CJC-1295 Is and How It Has Been Studied

CJC-1295 is a synthetic peptide in the class of growth hormone-releasing hormone (GHRH) analogs. Its backbone is based on the biologically active fragment of human growth hormone-releasing factor, hGRF(1-29), with amino acid substitutions intended to resist enzymatic breakdown. The defining feature of the molecule described in the original pharmacology work was a reactive chemical group that allowed the peptide to bind covalently to circulating albumin after injection; researchers reported that hGRF(1-29)-albumin bioconjugates activated the GRF receptor on the anterior pituitary in rats and identified CJC-1295 as a long-lasting GRF analog on that basis (PMID 15817669).

The "DAC" and "no DAC" naming

That albumin-binding element is usually called a drug affinity complex, abbreviated DAC. In the published trials, the peptide tested carried it. The label "CJC-1295 no DAC" is used outside the clinical literature to describe a modified GRF(1-29) peptide that has the amino acid substitutions but not the albumin-binding attachment — in other words, a shorter-acting molecule sold and discussed under the same brand-style name. The verified literature summarised in this course does not contain human trials of a "no DAC" version, and none of the studies below tested it. Any claim that the trial results transfer to a non-albumin-binding variant is an extrapolation, not a finding.

The compound has been studied in three broad settings: animal pharmacology, small controlled trials in healthy adults, and analytical or social-science work concerned with unregulated supply and doping control. Analytical chemists, for example, reported identifying CJC-1295 in an unknown pharmaceutical preparation submitted for testing (PMID 21204297), and separate teams developed detection methods for equine plasma (PMID 30938069).

Limits of the evidence in Module 1: the human record consists of a small number of early-phase studies in healthy volunteers, not long-term trials in patient populations. There is no verified human study of the "no DAC" form, and no head-to-head comparison of the two forms.

Module 2 — Mechanism as Described in the Literature

GHRH analogs act on GHRH receptors on somatotroph cells in the anterior pituitary. Binding stimulates synthesis and release of growth hormone (GH), which in turn drives hepatic production of insulin-like growth factor I (IGF-I). CJC-1295 was designed so that this stimulus persists: after injection, the peptide forms a bond with serum albumin, which slows clearance and extends receptor exposure. Researchers demonstrated receptor activation and the long-acting profile of the albumin bioconjugate in rats, describing CJC-1295 as a long-lasting GRF analog in that model (PMID 15817669).

A recurring mechanistic question is whether continuous stimulation flattens the normal pulsatile pattern of GH release. A clinical study addressed this directly and reported that pulsatile secretion of growth hormone persisted during continuous stimulation by CJC-1295 in healthy subjects, with the analysis indicating that pulse amplitude rather than pulse frequency accounted for the increase in GH output (PMID 17018654). Downstream of the pituitary, one group examined circulating proteins and reported that activation of the GH/IGF-1 axis by CJC-1295 produced measurable serum protein profile changes in normal adult subjects (PMID 19386527).

Because the mechanism runs through the pituitary rather than replacing GH directly, GHRH analogs are often described as preserving feedback regulation — somatostatin tone and IGF-I feedback still operate. That description is mechanistic reasoning found in the source literature, not a demonstrated clinical safety advantage.

Limits of the evidence in Module 2: mechanistic studies measured hormone concentrations and secretion patterns over days to weeks, not tissue-level or long-term consequences. Preserved pulsatility in healthy adults does not establish what happens with prolonged or repeated exposure, and the receptor pharmacology work was done in rats.

Module 3 — Reported Outcomes, Study by Study

The table below summarises what each verified study examined and what was reported. No study in this list was designed to test athletic performance, body composition change, or anti-ageing endpoints.

The healthy-adult dose-ranging data

The most detailed human dataset came from a randomised, double-blind, placebo-controlled study in healthy adults in which single subcutaneous doses of 30, 60, 125 and 250 µg/kg were administered and researchers reported mean GH concentrations increased 2- to 10-fold for six days or more, with IGF-I concentrations increased 1.5- to 3-fold for nine to eleven days (PMID 16352683). In the multiple-dose portion of the same study, researchers reported that mean IGF-I remained above baseline for up to 28 days after weekly or biweekly injections (PMID 16352683). These are hormone measurements in volunteers, not clinical outcomes.

Animal growth data

In a genetically GHRH-deficient model, the study reported that once-daily administration of CJC-1295 normalized growth in the GHRH knockout mouse, restoring growth toward that of normal littermates (PMID 16822960). That finding concerns replacement of an absent hormone signal in a deficiency model, which is a different biological question from administration to animals or people with an intact axis.

Accounts from outside the clinic

A netnographic study analysed how women in online communities discussed synthetic growth hormone and CJC-1295, and researchers described self-reported sourcing, self-managed administration and peer advice circulating in those forums (PMID 26771670). Such accounts document behaviour and belief; they are not measurements of efficacy or safety.

Limits of the evidence in Module 3: sample sizes were small, follow-up was short, and the endpoints were biomarkers — GH and IGF-I — rather than muscle mass, injury recovery, sleep quality or longevity. Surrogate hormone changes do not demonstrate clinical benefit, and none of these studies was powered to do so.

Module 4 — CJC-1295 Side Effects: What Studies Report

Safety information in the verified literature is limited and comes almost entirely from small early-phase work. In the dose-ranging study in healthy adults, researchers reported that CJC-1295 was well tolerated across the doses administered, with no serious adverse events attributed to the compound during the observation period (PMID 16352683). Injection-site reactions are a recognised feature of subcutaneous peptide administration generally; the verified papers do not provide a quantified adverse-event table that can be reproduced here.

The companion clinical analysis of secretion dynamics was designed to characterise GH pulse patterns rather than to catalogue adverse events, so it contributes little independent safety information beyond confirming that dosing was carried out in healthy volunteers under supervision (PMID 17018654). The proteomic study reported that activation of the GH/IGF-1 axis was accompanied by changes in circulating protein profiles in normal adult subjects, a biochemical observation whose long-term significance the authors did not resolve (PMID 19386527).

Two further sources bear on risk indirectly. Researchers reported identifying CJC-1295 in an unknown pharmaceutical preparation of uncertain provenance, illustrating that material circulating outside regulated channels may not match its label (PMID 21204297). And the netnographic analysis documented unsupervised, self-directed use described in online communities, where no laboratory monitoring or medical oversight was reported (PMID 26771670).

Limits of the evidence in Module 4: "well tolerated" in a short study of healthy volunteers is not the same as an established safety profile. The trials were too small and too brief to detect uncommon events, and there is no published long-term safety follow-up. Theoretical concerns associated with sustained IGF-I elevation — including effects on glucose handling and on tissues sensitive to growth signalling — were not tested to resolution in any verified study.

Module 5 — Pharmacokinetics Where Data Exist

The pharmacokinetic rationale for CJC-1295 is the albumin bond. In healthy adults, researchers reported an estimated terminal half-life of approximately 5.8 to 8.1 days, which is why single injections produced hormone elevations lasting far longer than those seen with short-acting GHRH fragments (PMID 16352683). The duration of the pharmacodynamic effect tracked that half-life: GH elevations over roughly a week and IGF-I elevations over one to two weeks after a single dose in that study (PMID 16352683).

The animal pharmacology work established the basis for that profile by showing that albumin bioconjugates of hGRF(1-29) retained receptor activity while persisting in circulation, which the authors used to identify CJC-1295 as a long-lasting analog (PMID 15817669). Detection science provides a second, indirect window: analysts developed an LC-MS/MS method to confirm CJC-1295 in equine plasma samples (PMID 30938069) and an immuno-polymerase chain reaction screen capable of detecting CJC-1295 and other GHRH analogs in equine plasma (PMID 30489688), work that depends on the peptide remaining measurable in circulation for a usable detection window.

Limits of the evidence in Module 5: these half-life figures apply to the albumin-binding form studied in that trial. A variant lacking the albumin-binding element would not be expected to share them, and no verified study characterised such a variant in humans. There are no published data on hepatic or renal impairment, pregnancy, older adults, or drug interactions.

Module 6 — Regulatory Status, Stated Factually

CJC-1295 is not an approved drug product in the United States, the European Union or other major jurisdictions. No marketing authorisation exists for it in any indication, and it did not progress through late-stage clinical development to approval. Material supplied under the name is typically labelled "research use only" (RUO), a designation indicating it is not intended for human or veterinary administration and is not manufactured to pharmaceutical standards.

Other peptides acting on the GHRH receptor have taken different regulatory paths: tesamorelin is an approved GHRH analog for a specific HIV-associated indication, and sermorelin was previously marketed in the United States before being withdrawn for commercial reasons. Those approvals do not extend to CJC-1295.

In compounding, the US Food and Drug Administration evaluates bulk drug substances nominated for use in pharmacy compounding under section 503A of the Federal Food, Drug, and Cosmetic Act. CJC-1295 has been placed in the agency's category of substances raising significant safety risks, a classification that in practice restricts its use in compounded preparations. In sport, GHRH analogs including CJC-1295 fall under the World Anti-Doping Agency's prohibited list of peptide hormones and growth factors, which is the practical reason detection assays exist — including the equine plasma methods published for anti-doping screening (PMID 30489688) and confirmation (PMID 30938069). Product-identity concerns are documented as well, with analysts reporting the identification of CJC-1295 in an unknown pharmaceutical preparation (PMID 21204297).

Limits of the evidence in Module 6: regulatory classifications change, differ by country and are not statements about biological effect. This section is general information and not legal advice; regulatory and licensing questions should be directed to a qualified professional in the relevant jurisdiction.

What the Studies Did Not Test

Reading the verified record as a whole, several gaps are explicit:

• The "no DAC" variant in humans. No verified human trial administered a non-albumin-binding version, so its dose-response, duration and tolerability are uncharacterised in this literature.
• Clinical outcomes. The human studies measured GH, IGF-I and serum proteins (PMID 19386527); none measured lean mass, strength, injury healing, sleep architecture or quality of life.
• Long-term safety. The tolerability statement in the healthy-adult study covered a short observation window, not months or years of exposure (PMID 16352683).
• Special populations. Older adults, people with metabolic disease, and those with a history of malignancy were not studied in the verified papers.
• Unsupervised patterns of use. The one study that examined real-world use did so through online discourse rather than clinical measurement (PMID 26771670).

This page is for educational purposes only and is not medical advice; consult a licensed physician for any question about health, medication or peptide-related research.

References

• 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)
• 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)
• 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, 2009)
• 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)
• 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)
• Netnography of Female Use of the Synthetic Growth Hormone CJC-1295: Pulses and Potions (Substance Use & Misuse, 2016)
• Identification of CJC-1295, a growth-hormone-releasing peptide, in an unknown pharmaceutical preparation (Drug Testing and Analysis, 2010)
• A method for confirming CJC-1295 abuse in equine plasma samples by LC-MS/MS (Drug Testing and Analysis, 2019)
• An immuno polymerase chain reaction screen for the detection of CJC-1295 and other growth-hormone-releasing hormone analogs in equine plasma (Drug Testing and Analysis, 2019)