CJC-1295 DAC vs No DAC: Identity and Half-Life Evidence
CJC-1295 with Drug Affinity Complex (DAC) and materials labeled “CJC-1295 No DAC” should not be treated as interchangeable laboratory reagents. DAC introduces albumin-binding chemistry, whereas “No DAC” commonly refers to Modified GRF 1-29 (Mod GRF 1-29), a modified growth hormone-releasing factor fragment without that group. The label alone does not establish molecular identity.
The often-repeated comparison between a multi-day half-life and a 30-minute half-life also needs qualification. Teichman et al. reported an estimated CJC-1295 half-life of 5.8–8.1 days in healthy adult human participants [1]. That result does not establish a half-life for Mod GRF 1-29 or an Alpha Carbon Labs material. The supplied references do not establish a directly comparable 30-minute value for a chemically verified No DAC reagent.
Chemical identity: more than a DAC label
These names concern modified analogs of the biologically active 1–29 fragment of growth hormone-releasing hormone (GHRH), also called growth hormone-releasing factor (GRF). Mod GRF 1-29 denotes a 29-residue analog with four amino acid substitutions. CJC-1295 incorporates albumin-binding chemistry in addition to peptide-backbone modifications. A comparison based only on “DAC present” or “DAC absent” cannot replace review of the complete sequence and conjugation chemistry.
For procurement and experimental reporting, document the sequence, terminal modifications, albumin-reactive group where applicable, and analytical evidence of identity. Evaluate the CJC-1295 listing against its specific chemical description and accompanying documentation, rather than assuming that a naming convention identifies the reagent used in a publication.
Albumin binding and experimental context
DAC introduces a reactive group that enables covalent association with albumin. Conjugation changes the molecular species under investigation and can alter its disposition. It does not establish permanent stability or protection against every degradation pathway.
Jette et al. investigated hGRF 1–29–albumin bioconjugates in rats and reported GRF receptor activation in the anterior pituitary [2]. This animal evidence concerns the investigated conjugates; it does not establish identical behavior in an isolated receptor assay, another species, or an Alpha Carbon Labs material.
In nonclinical assay design, record albumin availability and distinguish unconjugated peptide from albumin-associated material. An albumin-free assay does not reproduce an albumin-containing biological matrix. When reviewing peptide synthesis documentation, distinguish modifications to the peptide backbone from the chemistry used to introduce the albumin-reactive group.
What the half-life evidence establishes
In the healthy adult human study by Teichman et al., the estimated CJC-1295 half-life was 5.8–8.1 days [1]. This is a pharmacokinetic observation in that study population, not a measurement of laboratory shelf life, solution stability, receptor residence time, or persistence in cell culture. It is not a lot-specific specification for material sold by Alpha Carbon Labs.
A meaningful numerical comparison requires the exact molecular species, study model, sampled matrix, analytical method, and kinetic definition. Pharmacokinetic half-life, disappearance of an analyte from an in-vitro matrix, and duration of a receptor response are different measurements and should be reported separately.
The supplied material does not establish a substantiated head-to-head half-life comparison between CJC-1295 with DAC and chemically verified Mod GRF 1-29. A 30-minute No DAC half-life is therefore not presented here as a verified value. No in-vitro or in-silico half-life estimate is established by this comparison.
Exposure duration and downstream response are distinct
Ionescu and Frohman reported that growth hormone (GH) pulsatility persisted during continuous stimulation by CJC-1295 in human participants [3]. This human finding does not support describing DAC-associated exposure as producing exclusively nonpulsatile GH secretion. Peptide exposure and the timing of a downstream biological response are separate endpoints.
The human study by Ionescu and Frohman [3] does not establish a comparative pulsatility profile for Mod GRF 1-29, comparative receptor desensitization, or a comparative risk profile. It also does not predict the response time course in a nonclinical receptor assay. Those questions require measurements in the relevant experimental system.
Comparison for laboratory interpretation
| Feature | CJC-1295 with DAC | Mod GRF 1-29 / “No DAC” |
|---|---|---|
| Chemical identity | Modified GHRH analog incorporating albumin-binding chemistry; verify the complete structure. | Modified 29-residue GRF analog without DAC; the “No DAC” label alone does not verify sequence or terminal groups. |
| Half-life evidence | Estimated 5.8–8.1 days in healthy adult human participants studied by Teichman et al. [1]. | A directly comparable numerical half-life is not established by the supplied references. |
| Temporal response evidence | GH pulsatility persisted in human participants studied by Ionescu and Frohman [3]. | No comparative pulsatility conclusion is established here. |
| Nonclinical assay considerations | Account for albumin availability, conjugation state, and the molecular species detected. | Confirm identity and measure stability and response duration in the selected assay. |
| Applicability to supplied material | Published findings do not establish the identity, purity, stability, or activity of an Alpha Carbon Labs lot. | |
Analytical documentation and laboratory handling
Review lot-specific COA documents for analytical methods, results, and acceptance criteria. Chromatographic purity and mass-based identity measurements answer different questions. A chromatographic percentage alone does not establish sequence, conjugation state, or biological activity. Where those attributes affect an experiment, use appropriately validated analytical methods rather than inferring them from a product name.
For reproducible nonclinical work, record the lot identifier, chemical form, assay matrix, albumin presence, sampling times, and molecular species detected. Distinguish concentration measurements from receptor-response measurements. These are experimental documentation considerations, not validated protocols for a particular supplied material.
Consult the applicable safety data sheet, lot-specific storage instructions, and institutional chemical-hygiene procedures before handling. Material-specific hazard classifications and validated storage conditions are not supplied here and cannot be inferred from pharmacokinetic findings. The quality control page provides related internal documentation but does not replace review of the relevant lot records.
Frequently asked research questions
Is “CJC-1295 No DAC” a sufficient chemical identifier?
No. Although commonly used for Mod GRF 1-29, the label does not establish the full structure. Experimental records should report the verified chemical identity and modifications.
Can a published human half-life determine an in-vitro sampling schedule?
Not by itself. The 5.8–8.1-day estimate reported by Teichman et al. concerns healthy adult human participants [1]. An in-vitro sampling schedule requires stability and response measurements appropriate to the assay matrix and analytical endpoint.
Does this comparison establish equivalent or preferred reagents?
No. Reagent selection depends on the nonclinical research question, verified structure, and assay design. The evidence presented does not establish equivalence or a universal ranking.
References
- Teichman, S. L., et al. (2006). 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 & Metabolism, 91(3), 799-805. — https://pubmed.ncbi.nlm.nih.gov/16352683/
- Jette, L., et al. (2005). 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, 146(7), 3052-3058. — https://pubmed.ncbi.nlm.nih.gov/15817669/
- Ionescu, M., & Frohman, L. A. (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 & Metabolism, 91(12), 4792-4797. — https://pubmed.ncbi.nlm.nih.gov/16954158/
- Sackmann-Sala, L., et al. (2009). 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, 19(6), 471-477. — https://pubmed.ncbi.nlm.nih.gov/19477663/
- Alba, M., et al. (2006). Once-daily administration of CJC-1295, a long-acting growth hormone-releasing hormone (GHRH) analog, upregulates the GH/IGF-1 axis in healthy young adults. Clinical Endocrinology, 65(6), 751-758. — https://pubmed.ncbi.nlm.nih.gov/17121578/
- Clemmons, D. R., et al. (2005). Responses to CJC-1295, a long-acting growth hormone-releasing hormone analog, in human subjects. Pituitary, 8(1), 32-39. — https://pubmed.ncbi.nlm.nih.gov/16411082/
- Van Houtte, P. R., et al. (2010). Pharmacokinetics and pharmacodynamics of a novel long-acting GHRH analog in physiological models. Regulatory Peptides, 160(1-3), 82-87. — https://doi.org/10.1016/j.regpep.2009.11.011
- Campbell, R. M., et al. (2006). Modification of peptides with Drug Affinity Complex (DAC) technology for extending half-life in vivo. BioDrugs, 20(3), 159-166. — https://pubmed.ncbi.nlm.nih.gov/16752940/
Limitations: Alpha Carbon Labs materials are intended solely for nonclinical laboratory research. Published findings do not establish safety, effectiveness, approval, or suitability of the material sold for human or veterinary use.