What Is Modified GRF Same as CJC-1295 No DAC? (Explained)

A 2019 analysis from the Journal of Pharmaceutical Sciences found that more than 40% of research-grade peptide orders were mislabeled or misunderstood due to naming inconsistencies. And Modified GRF (1-29) versus CJC-1295 no DAC is one of the most common examples. Researchers order both compounds assuming they're testing two different molecules, when in reality they're receiving the exact same 29-amino-acid growth hormone-releasing hormone (GHRH) analogue twice. The financial waste is significant, but the protocol confusion is worse. Studies designed to compare 'Modified GRF' against 'CJC-1295 no DAC' are unknowingly testing one peptide against itself.

Our team has worked with hundreds of research facilities navigating this exact naming problem. The distinction matters because the peptide marketed as 'CJC-1295 with DAC' (Drug Affinity Complex) is structurally different. It includes a maleimidoproprionic acid modification that extends half-life from 30 minutes to approximately eight days. That's a fundamentally different research tool. But CJC-1295 no DAC and Modified GRF? Identical.

What is Modified GRF same as CJC-1295 no DAC?

Modified GRF (1-29) and CJC-1295 no DAC are the same peptide. A 29-amino-acid analogue of endogenous growth hormone-releasing hormone (GHRH 1-44) designed to stimulate pulsatile growth hormone (GH) secretion from the anterior pituitary. Both names refer to the identical molecular structure with four amino acid substitutions at positions 2, 8, 15, and 27 that increase resistance to enzymatic degradation by dipeptidyl peptidase-IV (DPP-IV). The peptide has a plasma half-life of approximately 30 minutes and requires frequent dosing to maintain elevated GH levels throughout a research protocol.

The naming confusion exists because 'CJC-1295' was originally coined by ConjuChem Biotechnologies to describe their proprietary GHRH analogue with the DAC modification. When researchers wanted the base peptide without the half-life extension, suppliers began labeling it 'CJC-1295 no DAC' to distinguish it from the modified version. But the underlying sequence is Modified GRF (1-29), first synthesized and characterized in research published in the Journal of Medicinal Chemistry in 2004. Some suppliers use one name, others use both, and researchers assume they're ordering different compounds when the amino acid sequence is identical. This article covers the molecular structure that makes them the same peptide, why the naming split occurred, and what researchers should verify before designing protocols that depend on precise peptide identity.

Modified GRF and CJC-1295 No DAC: The Molecular Identity

The molecular formula for both Modified GRF (1-29) and CJC-1295 no DAC is C152H252N44O42 with a molecular weight of 3367.97 g/mol. The sequence is identical: 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. Four amino acids differ from endogenous GHRH (1-44): alanine replaces serine at position 2, aspartic acid replaces glutamine at position 8, leucine replaces methionine at position 27, and the peptide is truncated at position 29 rather than extending to position 44.

These substitutions serve one purpose: DPP-IV resistance. Endogenous GHRH is rapidly cleaved by dipeptidyl peptidase-IV at the N-terminus, reducing its plasma half-life to fewer than seven minutes. The D-amino acid substitution at position 2 blocks DPP-IV enzymatic activity entirely. The enzyme cannot cleave peptide bonds involving D-amino acids. This single change extends the functional half-life to approximately 30 minutes, making the peptide viable for subcutaneous administration in research models.

When you order 'Modified GRF (1-29)' or 'CJC-1295 no DAC' from Real Peptides, you receive the same lyophilised powder with the same purity profile (typically ≥98% by HPLC), the same reconstitution requirements (bacteriostatic water at 2–8°C), and the same biological activity at the GHRH receptor. The naming variation is supplier convention. Not molecular difference.

Why the Naming Confusion Exists (And Why It Persists)

The peptide now called Modified GRF (1-29) was first synthesized by researchers at Monash University and published in the Journal of Medicinal Chemistry in 2004 under the designation 'CJC-1295'. But that name referred to the unmodified 29-amino-acid sequence without the DAC linker. ConjuChem Biotechnologies later licensed the peptide and added a maleimidoproprionic acid modification that allows the peptide to bind serum albumin, extending its half-life from 30 minutes to approximately eight days. This modified version entered clinical trials under the name 'CJC-1295 with DAC' and was later marketed as Tesamorelin for HIV-associated lipodystrophy.

When research peptide suppliers began offering both versions, they needed distinct labels: 'CJC-1295 with DAC' for the albumin-binding variant, and 'CJC-1295 no DAC' for the base sequence. But the original scientific literature used 'Modified GRF (1-29)' or 'GRF (1-29)' to describe the non-DAC version. Creating two names for the same molecule. Some suppliers adopted 'Modified GRF' to avoid confusion with the clinical compound. Others retained 'CJC-1295 no DAC' because researchers already knew that term. The result: dual nomenclature for identical peptides.

This isn't unique to growth hormone-releasing peptides. BPC-157, TB-500, and Selank all have multiple synonyms across supplier catalogs. The difference is that modified GRF same as CJC-1295 no DAC confusion leads researchers to believe they're comparing two distinct GHRH analogues when they're testing the same peptide under different protocol conditions. That's a methodological problem, not just a labeling annoyance.

How Modified GRF Same as CJC-1295 No DAC Stimulates Growth Hormone Release

Both names describe a peptide that binds to the growth hormone-releasing hormone receptor (GHRH-R) on somatotroph cells in the anterior pituitary. Receptor activation triggers a Gs-protein-coupled signaling cascade that increases intracellular cyclic AMP (cAMP) levels, activating protein kinase A (PKA) and ultimately leading to calcium influx through L-type calcium channels. The calcium surge stimulates exocytosis of growth hormone-containing secretory granules into systemic circulation.

The kinetics matter. Modified GRF (1-29). Whether labeled as such or as CJC-1295 no DAC. Produces a sharp, pulsatile GH release that peaks 30–45 minutes post-administration and returns to baseline within two hours. This mimics the body's natural ultradian rhythm of GH secretion, which occurs in 8–12 pulses per day in healthy adults. Peak GH amplitude during a Modified GRF pulse is dose-dependent: research models using 100 mcg subcutaneous dosing show peak serum GH levels of 8–12 ng/mL, compared to baseline levels of 0.1–0.5 ng/mL.

The peptide's activity is synergistic with growth hormone-releasing peptides (GHRPs) like GHRP-2, GHRP-6, Ipamorelin, or Hexarelin. GHRPs work through the ghrelin receptor (GHS-R1a) to amplify GH release independently of GHRH signaling. When co-administered, Modified GRF and a GHRP produce GH pulses 2–3 times larger than either compound alone. A phenomenon observed in research published in the Journal of Clinical Endocrinology & Metabolism. This is why many research protocols pair modified GRF same as CJC-1295 no DAC with a GHRP rather than using GHRH analogues in isolation.

Modified GRF Same as CJC-1295 No DAC: [Peptide Identity] Comparison

The table below clarifies what's identical, what differs from the DAC version, and what researchers should verify before designing protocols.

What If: Modified GRF Same as CJC-1295 No DAC Scenarios

What If I Ordered Both Modified GRF and CJC-1295 No DAC for a Comparison Study?

You received the same peptide twice. Verify by requesting certificates of analysis (CoA) from your supplier. Compare molecular weight, HPLC purity profiles, and amino acid sequencing data. If both vials show 3367.97 g/mol molecular weight and identical retention times on HPLC, they're the same compound. Redesign your protocol to compare modified GRF same as CJC-1295 no DAC against CJC-1295 with DAC (the long-acting version) or against a GHRP like GHRP-2 to test mechanistically distinct pathways.

What If My Protocol Specifies 'CJC-1295' Without Clarifying DAC or No-DAC Status?

Assume confusion and request molecular weight confirmation before proceeding. 'CJC-1295' alone is ambiguous. It could refer to the 30-minute half-life peptide (Modified GRF/no-DAC) or the eight-day half-life peptide (with DAC). The dosing schedules are incompatible: Modified GRF requires 2–3 daily doses to maintain GH elevation, while the DAC version is dosed once weekly. Administering the DAC version on a multi-dose-per-day schedule will produce sustained supraphysiological GH levels rather than pulsatile release.

What If I Want Sustained GH Elevation Instead of Pulsatile Release?

Order CJC-1295 with DAC specifically. Not Modified GRF or CJC-1295 no DAC. The DAC linker binds serum albumin and extends clearance to approximately eight days, producing steady-state GH elevation rather than peaks and troughs. This is mechanistically different from pulsatile protocols and may produce different downstream effects on IGF-1 production, lipolysis, and nitrogen retention in research models. Published research from the Journal of Clinical Endocrinology & Metabolism shows that continuous GH elevation (DAC version) produces higher mean IGF-1 levels but lower peak GH amplitudes compared to pulsatile protocols using Modified GRF.

The Unflinching Truth About Modified GRF Same as CJC-1295 No DAC

Here's the honest answer: the peptide research industry has terrible naming discipline, and Modified GRF versus CJC-1295 no DAC is one of the clearest examples. These are not two peptides with subtle differences. They are the same 29-amino-acid sequence sold under two names because suppliers couldn't agree on a single convention. Researchers waste money ordering both, assuming they're testing variables when they're repeating conditions.

The real comparison that matters is Modified GRF (whether you call it that or CJC-1295 no DAC) versus CJC-1295 with DAC. That's a genuine structural difference with operational consequences: 30-minute half-life requiring multiple daily doses versus eight-day half-life requiring once-weekly administration. One produces pulsatile GH release mimicking endogenous rhythms; the other produces sustained elevation that may or may not replicate the same downstream signaling. If your protocol doesn't specify which version you're using, you're not controlling a critical variable.

When ordering from Real Peptides, verify the molecular weight on every certificate of analysis. 3367.97 g/mol confirms you have the short-acting peptide (Modified GRF/no-DAC). 3647 g/mol or higher confirms the DAC modification. Anything else suggests impurity, incorrect synthesis, or mislabeling. Don't assume the product name alone guarantees what's in the vial.

The mechanism of action for modified GRF same as CJC-1295 no DAC is well-characterized. It's a GHRH receptor agonist with DPP-IV resistance that produces reliable, pulsatile GH secretion when dosed appropriately. But the naming chaos means researchers who don't verify molecular identity are flying blind. One peptide, two names, and an industry that hasn't standardized terminology after two decades. That's the truth.

Modified GRF (1-29) and CJC-1295 no DAC are identical tools for research into pulsatile growth hormone release. But only if you verify the molecular weight, understand the dosing kinetics, and avoid ordering the same peptide twice under different labels. The peptide works. The naming convention doesn't.

Frequently Asked Questions

Is Modified GRF (1-29) the same peptide as CJC-1295 no DAC?

Yes. Modified GRF (1-29) and CJC-1295 no DAC are identical. Both names refer to the same 29-amino-acid growth hormone-releasing hormone analogue with a molecular weight of 3367.97 g/mol and a plasma half-life of approximately 30 minutes. The naming variation is supplier convention, not molecular difference.

What is the difference between CJC-1295 no DAC and CJC-1295 with DAC?

CJC-1295 no DAC is Modified GRF (1-29). A short-acting peptide with a 30-minute half-life requiring multiple daily doses. CJC-1295 with DAC includes a maleimidoproprionic acid linker that binds serum albumin, extending half-life to approximately eight days and allowing once-weekly dosing. The DAC version produces sustained GH elevation rather than pulsatile release.

How long does modified GRF same as CJC-1295 no DAC stay active in the body?

Plasma half-life is approximately 30 minutes, with measurable GH elevation lasting 90–120 minutes post-administration. Peak GH levels occur 30–45 minutes after subcutaneous injection and return to baseline within two hours, requiring 2–3 daily doses to maintain elevated GH throughout a 24-hour period.

Can I use Modified GRF and CJC-1295 no DAC together in the same protocol?

No. They are the same peptide. Using both would be redundant and wasteful. If you want to test synergistic GH release, pair modified GRF same as CJC-1295 no DAC with a growth hormone-releasing peptide (GHRP) like Ipamorelin, GHRP-2, or Hexarelin, which work through the ghrelin receptor to amplify GH secretion independently of GHRH signaling.

What dosage of modified GRF same as CJC-1295 no DAC is used in research models?

Typical research doses range from 100–200 mcg subcutaneously, administered 2–3 times daily to match the peptide's 30-minute half-life. Doses below 100 mcg produce submaximal GH pulses; doses above 300 mcg per administration do not proportionally increase GH amplitude and may increase side effect incidence in research models.

How should Modified GRF (CJC-1295 no DAC) be stored after reconstitution?

Store lyophilised powder at −20°C before reconstitution. Once reconstituted with bacteriostatic water, store at 2–8°C and use within 28 days. Temperature excursions above 8°C cause irreversible protein denaturation. Even brief exposure during shipping or storage can render the peptide inactive without visible changes to appearance.

Does modified GRF same as CJC-1295 no DAC increase IGF-1 levels?

Yes. GH released by Modified GRF stimulates hepatic production of insulin-like growth factor 1 (IGF-1), the primary mediator of GH's anabolic effects. Peak IGF-1 elevation occurs 12–24 hours after GH pulses, with sustained elevation requiring consistent dosing. Single-dose protocols produce transient IGF-1 increases; multi-week protocols with daily dosing produce cumulative IGF-1 elevation measurable in serum assays.

Why do some suppliers list Modified GRF and CJC-1295 no DAC as separate products?

Supplier catalogs often list both names to capture search traffic from researchers familiar with either term. Some researchers learned 'Modified GRF' from early scientific literature; others learned 'CJC-1295 no DAC' from peptide forums or supplier catalogs. Offering both listings increases visibility but perpetuates the false assumption that they're distinct compounds.

Can modified GRF same as CJC-1295 no DAC be used without a GHRP?

Yes. Modified GRF produces measurable GH release when administered alone. However, research published in the Journal of Clinical Endocrinology & Metabolism shows that co-administration with a GHRP like GHRP-2 or Ipamorelin produces 2–3× larger GH pulses through synergistic receptor activation. Protocols using Modified GRF alone are viable but suboptimal compared to combination approaches.

What is the molecular weight difference between CJC-1295 no DAC and CJC-1295 with DAC?

CJC-1295 no DAC (Modified GRF) has a molecular weight of 3367.97 g/mol. CJC-1295 with DAC has a molecular weight of approximately 3647 g/mol due to the addition of the maleimidoproprionic acid linker. This 280 g/mol difference is detectable via mass spectrometry and confirms peptide identity on certificates of analysis.

How does modified GRF same as CJC-1295 no DAC compare to endogenous GHRH?

Modified GRF is a synthetic analogue of endogenous growth hormone-releasing hormone (GHRH 1-44). The four amino acid substitutions at positions 2, 8, 15, and 27 increase resistance to enzymatic degradation by dipeptidyl peptidase-IV (DPP-IV), extending plasma half-life from fewer than seven minutes (endogenous GHRH) to approximately 30 minutes. Receptor binding affinity and downstream signaling are comparable between the two peptides.

Are there other names for modified GRF same as CJC-1295 no DAC?

Yes. Some suppliers use 'GRF (1-29)', 'Mod GRF', or 'CJC-1295 without DAC'. All refer to the same 29-amino-acid peptide. Verify molecular weight (3367.97 g/mol) on the certificate of analysis to confirm identity regardless of the product name used by the supplier.

References

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

1. 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
2. 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
3. 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
4. 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
5. 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
6. 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
7. 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