CJC-1295 + Ipamorelin (5mg/5mg) · Research brief

Mod GRF 1-29 Same as CJC-1295 No DAC? (Explained)

Real Peptides Research TeamEditorial

Updated April 9, 20269 min read

60 WORDS

Short answer

Key takeaways

Mod GRF 1-29 and CJC-1295 no DAC are identical peptides. Both describe tetrasubstituted GRF(1-29)NH2 with the same 29-amino-acid sequence and 30-minute half-life.
The naming distinction arose during clinical development when researchers needed to differentiate the short-acting base peptide from the DAC-conjugated long-acting version.
CJC-1295 with DAC is a different compound entirely, with a 6–8 day half-life and sustained GH elevation rather than pulsatile release.
Both Mod GRF 1-29 and CJC-1295 no DAC require acidic reconstitution media (pH 3–5) and refrigerated storage at 2–8°C to prevent aggregation and degradation.
Verification of peptide identity requires certificate-of-analysis documentation showing molecular weight of 3367.9 Da ±2 Da and purity ≥98% by HPLC.

The most expensive mistake in peptide research isn't contamination. It's ordering the same peptide twice under different names. Mod GRF 1-29 and CJC-1295 no DAC are identical compounds: both describe tetrasubstituted GRF(1-29)NH2, a synthetic analog of growth hormone-releasing hormone (GHRH) with four amino acid substitutions at positions 2, 8, 15, and 27 that extend plasma stability from under two minutes to approximately 30 minutes. The naming confusion stems from early pharmaceutical development. CJC-1295 was the original drug candidate name, and when the Drug Affinity Complex (DAC) moiety was removed during clinical trials, researchers needed a way to distinguish the short-acting version from the long-acting DAC-conjugated form. Mod GRF 1-29 became the common shorthand for the unmodified peptide, but chemically, structurally, and functionally, they are the same molecule.

Our team has guided hundreds of research labs through peptide sourcing protocols. The Mod GRF 1-29 vs CJC-1295 no DAC distinction trips up even experienced researchers because the nomenclature wasn't standardised. It evolved from vendor convention rather than regulatory classification.

Is Mod GRF 1-29 the same as CJC-1295 no DAC?

Yes. Mod GRF 1-29 and CJC-1295 no DAC are identical peptides. Both refer to tetrasubstituted GRF(1-29)NH2, a 29-amino-acid GHRH analog with substitutions at positions 2, 8, 15, and 27 that extend its half-life to approximately 30 minutes. The two names describe the same molecular structure and produce identical pharmacokinetic profiles. The naming variation exists purely for historical reasons related to early clinical development, not chemical difference.

The confusion runs deeper than most guides acknowledge. CJC-1295 originally referred to a DAC-conjugated peptide designed for weekly dosing. When researchers wanted the growth hormone pulse without the DAC extension, they couldn't keep calling it CJC-1295 without confusion. Mod GRF 1-29 emerged as the clearer descriptor, but vendors never universally adopted it. This piece covers the exact molecular structure both names describe, why the DAC distinction matters for research design, and what preparation errors occur when researchers assume these are different compounds.

The Chemical Structure Behind Both Names

Both Mod GRF 1-29 and CJC-1295 no DAC describe the same 29-amino-acid sequence: Tyr-D-Ala-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 four substitutions. D-alanine at position 2, alanine at position 8, glutamine at position 15, and alanine at position 27. Were engineered specifically to resist enzymatic degradation by dipeptidyl peptidase-IV (DPP-IV) and neutral endopeptidase (NEP), the two enzymes that rapidly cleave native GHRH in circulation. Without these substitutions, endogenous GHRH has a plasma half-life of under two minutes, making it impractical for research applications requiring sustained receptor occupancy.

The molecular weight is 3367.9 Da. The isoelectric point sits at approximately pH 9.8, meaning the peptide carries a net positive charge at physiological pH and requires acidic reconstitution media (pH 3–5) to maintain solubility without aggregation. This is critical: laboratories that reconstitute Mod GRF 1-29 or CJC-1295 no DAC in neutral or alkaline solutions often observe white precipitate within 24–48 hours. That's irreversible aggregation, not contamination. The peptide is synthesised via solid-phase peptide synthesis (SPPS) using Fmoc chemistry, purified by reverse-phase HPLC to ≥98% purity, and lyophilised with mannitol or trehalose as a cryoprotectant to preserve tertiary structure during freeze-drying.

In our experience working with research teams across neuropeptide and metabolic studies, the reconstitution pH error is where most protocols fail. The peptide chemistry doesn't change based on what you call it. Mod GRF 1-29 and CJC-1295 no DAC both require acidic reconstitution media and refrigerated storage at 2–8°C post-reconstitution. Real Peptides supplies both nomenclature forms with certificate-of-analysis documentation showing identical mass spectrometry and HPLC profiles, because they are the same compound produced under the same synthesis protocol.

DAC vs No DAC: Why the Distinction Exists

The Drug Affinity Complex (DAC) is a synthetic chemical moiety that binds non-covalently to serum albumin, dramatically extending the half-life of conjugated peptides from minutes to days. CJC-1295 with DAC. Sometimes called CJC-1295 DAC or simply CJC-1295 without the 'no DAC' qualifier. Has a half-life of 6–8 days, allowing for once-weekly administration and sustained elevation of growth hormone and IGF-1 levels. CJC-1295 no DAC, by contrast, retains the 30-minute half-life of the base peptide, requiring multiple daily administrations to maintain pulsatile GH release that mimics endogenous secretory patterns.

The naming problem arose during clinical development. ConjuChem Biotechnologies originally developed CJC-1295 with DAC for therapeutic use in growth hormone deficiency. The DAC conjugation was the defining feature. When researchers wanted the same GHRH analog without the DAC extension for studies requiring physiological GH pulsatility rather than sustained elevation, they needed a way to distinguish it. Some vendors called it CJC-1295 no DAC. Others adopted Mod GRF 1-29, referencing the modification of native GRF(1-29) without implying DAC conjugation. Both names stuck, creating the current nomenclature overlap.

Pharmacologically, the difference matters. CJC-1295 with DAC produces supraphysiological, sustained GH elevation. Useful for studying chronic GH exposure effects but not for replicating normal pulsatile secretion. Mod GRF 1-29 and CJC-1295 no DAC produce sharp GH peaks 15–30 minutes post-administration that return to baseline within 90–120 minutes, matching the 3–4 hour ultradian rhythm of endogenous GH secretion. Research protocols examining GH pulse amplitude, frequency modulation, or circadian rhythmicity require the no-DAC version. Confusion between the two leads to fundamentally different experimental outcomes. A researcher expecting pulsatile release who receives DAC-conjugated peptide will observe blunted peak amplitude and elevated baseline GH instead.

Mod GRF 1-29 vs CJC-1295 No DAC: Sourcing and Verification

Verifying peptide identity requires mass spectrometry and HPLC analysis. Visual inspection and vendor labeling are insufficient. A certificate of analysis (CoA) should list molecular weight within ±2 Da of the theoretical mass (3367.9 Da for Mod GRF 1-29 and CJC-1295 no DAC), purity ≥98% by HPLC, and peptide content by weight (typically 1–5 mg per vial). If the CoA lists molecular weight above 4500 Da, the peptide contains DAC regardless of labeling. If no CoA is provided, the peptide should not be used in research. Synthesis variability, incomplete deprotection, and oxidation byproducts are common quality control failures in peptide manufacturing.

What If: Mod GRF 1-29 and CJC-1295 No DAC Scenarios

What If I Order Both and Receive Identical Vials?

You likely received the same peptide under two different product names. Verify by comparing certificates of analysis: if both list molecular weight at 3367.9 Da and identical HPLC purity percentages, they are the same compound. The practical implication is that you now have duplicate inventory. Adjust your reconstitution and dosing schedules accordingly rather than treating them as separate compounds. Do not mix vials assuming they contain different peptides; the amino acid sequence and pharmacokinetic profile are identical.

What If My Vendor Only Lists CJC-1295 Without Specifying DAC Status?

Request clarification on molecular weight and half-life from the vendor before ordering. If the product description mentions weekly dosing or sustained GH elevation, it likely contains DAC. If it specifies multiple daily administrations or pulsatile release, it's the no-DAC version. Ambiguous labeling is a quality control red flag. Reputable suppliers like Real Peptides explicitly distinguish CJC-1295 with DAC from Mod GRF 1-29 or CJC-1295 no DAC in product listings to prevent exactly this sourcing error.

What If I Accidentally Reconstitute Mod GRF 1-29 at Neutral pH?

The peptide will aggregate within 24–48 hours, forming visible white precipitate that cannot be reversed. This is not contamination. It's irreversible structural denaturation caused by incorrect pH. Discard the vial and reconstitute a new aliquot using bacteriostatic water adjusted to pH 3–5 with acetic acid. Aggregated peptide loses receptor binding affinity and should not be administered regardless of research application.

The Unflinching Truth About Peptide Nomenclature

Here's the honest answer: the Mod GRF 1-29 vs CJC-1295 no DAC confusion exists because the peptide research industry never standardised naming conventions. Vendors use whichever term drives more search traffic. Academic literature alternates between both. The peptide itself hasn't changed. It's the same 29-amino-acid sequence synthesised the same way with the same pharmacokinetic profile. The real problem isn't the naming overlap; it's that researchers waste time and budget ordering what they think are two different compounds when one would suffice.

The DAC distinction is the only nomenclature issue that matters operationally. CJC-1295 with DAC is chemically and functionally distinct. Mod GRF 1-29 and CJC-1295 no DAC are not. If your research protocol requires pulsatile GH release, either name works. Verify the molecular weight is 3367.9 Da and proceed. If your protocol assumes they're different peptides and you're running parallel studies, you're duplicating effort on identical compounds. We mean this sincerely: the compound doesn't care what you call it. The chemistry, the receptor binding, the GH secretagogue effect. All identical.

The gap between vendor marketing and molecular reality is where most research errors occur. A supplier calling this peptide 'Modified GRF' or 'Sermorelin analog' or 'CJC-1295 short-acting' doesn't change the structure. Mass spectrometry is the ground truth. If the mass is 3367.9 Da and the sequence is verified by amino acid analysis, the nomenclature is secondary. Focus on verification, not labeling.

If the peptide nomenclature still feels opaque, that's intentional. Clearer naming would reduce the ability to market the same compound under multiple SKUs. Our team's assessment after working across hundreds of peptide protocols: verify the molecular weight, confirm the sequence if possible, ignore the marketing label. Explore high-purity research peptides with full CoA transparency and exact amino-acid sequencing. The chemistry is what defines the peptide, not the product name.

References

Peer-reviewed sources on CJC-1295 indexed in PubMed, listed for research context. Real Peptides supplies CJC-1295 for laboratory research use only.

Netnography of Female Use of the Synthetic Growth Hormone CJC-1295: Pulses and Potions. Substance use & misuse, 2016. PMID 26771670. doi:10.3109/10826084.2015.1082595
Identification of CJC-1295, a growth-hormone-releasing peptide, in an unknown pharmaceutical preparation. Drug testing and analysis, 2010. PMID 21204297. doi:10.1002/dta.233
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 : official journal of the Growth Hormone Research Society and the International IGF Research Society, 2009. PMID 19386527. doi:10.1016/j.ghir.2009.03.001
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. PMID 16352683. doi:10.1210/jc.2005-1536
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. PMID 16822960. doi:10.1152/ajpendo.00201.2006
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. PMID 17018654. doi:10.1210/jc.2006-1702
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. PMID 15817669. doi:10.1210/en.2004-1286

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Questions

Yes, Mod GRF 1-29 and CJC-1295 no DAC are identical peptides — both refer to tetrasubstituted GRF(1-29)NH2, a 29-amino-acid GHRH analog with the same molecular weight (3367.9 Da), amino acid sequence, and 30-minute plasma half-life. The two names emerged from different stages of peptide development and vendor convention, but they describe the same compound with identical pharmacokinetic and pharmacodynamic properties. Certificate-of-analysis documentation from reputable suppliers will show matching mass spectrometry and HPLC profiles for both product names.

CJC-1295 with DAC contains a Drug Affinity Complex moiety that binds to serum albumin and extends the peptide’s half-life to 6–8 days, allowing for once-weekly administration and sustained growth hormone elevation. CJC-1295 no DAC lacks this conjugate and has a 30-minute half-life, requiring multiple daily doses to maintain pulsatile GH release that mimics endogenous secretory patterns. The DAC addition increases molecular weight from 3367.9 Da to approximately 5000 Da and fundamentally changes the dosing protocol and pharmacological profile — they are not interchangeable in research applications.

Yes, because they are the same peptide. If your protocol specifies one and your supplier provides the other, verify the molecular weight is 3367.9 Da via certificate of analysis and proceed without protocol modification. The amino acid sequence, receptor binding affinity, GH secretagogue potency, and reconstitution requirements are identical. The only operational consideration is ensuring you did not accidentally receive CJC-1295 with DAC, which has a molecular weight above 4500 Da and requires a completely different dosing schedule.

Reconstitute with bacteriostatic water adjusted to pH 3–5 using acetic acid to prevent peptide aggregation. The isoelectric point of this peptide is approximately pH 9.8, meaning it carries a positive charge at neutral pH and will aggregate if reconstituted in unbuffered or alkaline solutions. Use 1–2 mL bacteriostatic water per milligram of peptide, swirl gently to dissolve (do not shake), and store at 2–8°C for up to 28 days. If white precipitate forms, the peptide has aggregated irreversibly and must be discarded — this is a pH error, not contamination.

Vendor listings often reflect search term optimization rather than chemical distinction — researchers searching for ‘Mod GRF 1-29’ and ‘CJC-1295 no DAC’ represent two separate search intent patterns even though the compounds are identical. Some suppliers maintain separate SKUs to capture both nomenclature variations, while others list one name with the alternate as a synonym. This is a marketing convention, not a formulation difference. Always verify peptide identity via certificate of analysis showing molecular weight and HPLC purity rather than relying on product naming alone.

Research protocols typically use 100–200 mcg per administration, delivered 2–3 times daily to maintain pulsatile growth hormone release. The 30-minute half-life requires multiple daily doses to sustain receptor occupancy throughout ultradian GH secretory cycles. Dosing immediately before sleep and upon waking captures the two largest endogenous GH pulses. This is fundamentally different from CJC-1295 with DAC, which uses 1–2 mg weekly due to its extended half-life — confusing the two leads to either subtherapeutic dosing or sustained supraphysiological GH elevation depending on which compound was administered.

Request a certificate of analysis from the supplier and verify the molecular weight is 3367.9 Da ±2 Da via mass spectrometry. If the molecular weight exceeds 4500 Da, the peptide contains the DAC moiety regardless of product labeling. HPLC purity should be ≥98%, and peptide content by weight should match the labeled amount per vial. Reputable suppliers provide CoA documentation with every batch — absence of this documentation is a quality control red flag and the peptide should not be used in research applications.

Yes, lyophilised (freeze-dried) Mod GRF 1-29 and CJC-1295 no DAC can be stored at −20°C for 12–24 months before reconstitution without significant degradation, provided the vials remain sealed and moisture-free. Once reconstituted in bacteriostatic water at pH 3–5, the peptide must be refrigerated at 2–8°C and used within 28 days. Temperature excursions above 8°C or exposure to UV light accelerate oxidation of methionine and tryptophan residues, reducing receptor binding affinity — this degradation is not visually detectable, making proper storage non-negotiable for maintaining research-grade purity.

Mod GRF 1-29 acts as a growth hormone-releasing hormone (GHRH) receptor agonist, binding to GHRH receptors on somatotroph cells in the anterior pituitary gland and stimulating pulsatile growth hormone secretion. The four amino acid substitutions at positions 2, 8, 15, and 27 resist degradation by dipeptidyl peptidase-IV and neutral endopeptidase, extending the half-life from under two minutes (native GHRH) to approximately 30 minutes. This extended stability allows physiological GH pulse amplitude and frequency without the sustained elevation characteristic of DAC-conjugated analogs, making it suitable for research examining endogenous GH secretory dynamics.

No — because they are the same peptide, the GH secretagogue potency, receptor binding affinity (Ki ~0.7 nM at GHRH receptors), and dose-response curve are identical. Any perceived potency difference in research outcomes reflects variability in peptide purity, storage conditions, reconstitution pH, or administration timing rather than intrinsic molecular differences. Properly synthesised and stored peptides under both names produce statistically equivalent GH peak amplitudes at identical dosages when administered under controlled conditions.

RESEARCH USE ONLY · NOT EVALUATED BY THE FDA