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

CJC-1295 No DAC Half-Life? (7-Day Breakdown)

RP
Real Peptides Research TeamEditorial
Updated March 3, 20269 min read
50 WORDS

Short answer

The half-life of CJC-1295 No DAC is approximately 30 minutes following subcutaneous administration. Not the multi-day duration many assume based on the DAC-modified version. This short plasma half-life results from the absence of Drug Affinity Complex (DAC) technology, which would otherwise bind the peptide to albumin and extend systemic circulation.

Key takeaways

  • CJC-1295 No DAC has a plasma half-life of approximately 30 minutes, requiring 2–3 daily doses to maintain pulsatile GH elevation.
  • The absence of the DAC modification eliminates albumin binding, causing rapid enzymatic degradation via DPP-IV and other proteases.
  • Storage stability (12–24 months lyophilised, 28 days reconstituted at 2–8°C) operates independently of plasma half-life. Both timelines must be managed separately.
  • CJC-1295 with DAC extends half-life to 6–8 days through covalent albumin binding, creating sustained tonic GH elevation rather than discrete pulses.
  • Dosing frequency for CJC-1295 No DAC mirrors native GHRH patterns. Short-lived, pulsatile, and tightly controlled by injection timing.
  • Co-administration with GHRPs amplifies GH release synergistically, allowing researchers to fine-tune pulse amplitude and frequency.

The half-life of CJC-1295 No DAC is approximately 30 minutes following subcutaneous administration. Not the multi-day duration many assume based on the DAC-modified version. This short plasma half-life results from the absence of Drug Affinity Complex (DAC) technology, which would otherwise bind the peptide to albumin and extend systemic circulation. Without that modification, CJC-1295 No DAC behaves like native GHRH (growth hormone-releasing hormone). It triggers a sharp, pulsatile GH release within minutes, peaks around 15–30 minutes post-injection, and clears from the bloodstream within two hours.

Our team has guided researchers through dozens of protocols involving modified GHRH analogs. The confusion around CJC-1295 No DAC's pharmacokinetics stems from conflicting nomenclature. The same base peptide structure is sold under different names depending on whether the DAC group is attached.

What's the half-life of CJC-1295 No DAC, and why does it matter for research design?

CJC-1295 No DAC has a plasma half-life of approximately 30 minutes, meaning it's eliminated from systemic circulation within 90–120 minutes post-injection. This short duration requires multiple daily dosing (typically 2–3 times per day) to maintain elevated GH pulses, contrasting sharply with the DAC-modified version's 6–8 day half-life. The pharmacokinetic difference directly impacts study design, dosing frequency, and interpretability of GH response curves.

Most researchers mistakenly treat CJC-1295 No DAC as a long-acting compound because they've conflated it with Modified GRF (1-29) or assumed the 'CJC-1295' label always includes DAC. It doesn't. The absence of the DAC modification means the peptide doesn't bind to serum albumin. It circulates freely, acts rapidly, and degrades quickly via enzymatic cleavage at the N-terminus. This piece covers the exact mechanism behind the 30-minute half-life, what that means for experimental protocols, how storage stability differs from plasma stability, and the common preparation mistakes that researchers make when dosing short-acting GHRH analogs.

The Pharmacokinetic Profile: Why 30 Minutes Matters

CJC-1295 No DAC's 30-minute half-life is a direct consequence of its molecular structure. Without the Drug Affinity Complex. A maleimido-propionic acid conjugate that binds covalently to lysine residues on serum albumin. The peptide circulates as a free, unbound molecule. Free peptides are subject to rapid enzymatic degradation by dipeptidyl peptidase-IV (DPP-IV) and other proteases in the bloodstream, which cleave amino acids from the N-terminus and render the peptide inactive within minutes.

The 30-minute figure represents the time required for plasma concentration to decrease by 50%. In practice, that means subcutaneous injection delivers a sharp GH pulse within 15–30 minutes, peaks between 30–60 minutes, and returns to baseline GH levels within 90–120 minutes. This mirrors the physiological pattern of endogenous GHRH release. Which is also pulsatile and short-lived. Researchers working with CJC-1295 No DAC are essentially replicating the body's natural GH-releasing rhythm, not creating sustained supraphysiological elevation.

Compare this to CJC-1295 with DAC, where the albumin-binding modification extends the half-life to 6–8 days. The DAC version produces a sustained, tonic elevation of GH rather than discrete pulses. Both peptides stimulate the same receptor. The GHRH receptor on anterior pituitary somatotrophs. But the kinetics, dosing requirements, and physiological effects diverge completely because of one structural modification.

Storage Stability vs Plasma Half-Life: Two Different Timelines

The 30-minute plasma half-life does not dictate storage stability. These are separate processes governed by different mechanisms. Plasma half-life refers to how long the peptide remains active in the bloodstream after injection. Storage stability refers to how long the lyophilised or reconstituted peptide remains structurally intact under controlled conditions before degradation.

Unreconstituted CJC-1295 No DAC, stored as lyophilised powder at −20°C, remains stable for 12–24 months. The freeze-dried state protects the peptide from hydrolytic degradation, oxidation, and microbial contamination. Once reconstituted with bacteriostatic water, the peptide must be refrigerated at 2–8°C and used within 28 days. After that, enzymatic and chemical degradation measurably reduce potency even in sterile, temperature-controlled conditions.

The confusion arises because researchers conflate biological half-life with chemical stability. A peptide can have a 30-minute half-life in plasma and a 28-day shelf life in solution. Those timelines operate on different axes. Temperature excursions during storage (e.g., leaving a vial at room temperature overnight) cause irreversible protein denaturation that neither appearance nor potency testing at the bench can detect. The peptide may look clear and colourless, but the amino acid sequence has been compromised.

CJC-1295 No DAC Half-Life: Dosing Protocol Implications

Peptide Version Plasma Half-Life Typical Dosing Frequency GH Release Pattern Albumin Binding Primary Use Case
CJC-1295 No DAC ~30 minutes 2–3× daily Pulsatile (mimics endogenous GHRH) None Short-term GH pulse studies, circadian rhythm protocols
CJC-1295 with DAC 6–8 days 1–2× weekly Sustained tonic elevation Yes (via DAC modification) Long-term GH elevation studies, chronic exposure models
Native GHRH (1-29) <10 minutes Continuous infusion or multiple daily Pulsatile (extremely short-lived) None Acute receptor response studies
Modified GRF (1-29) ~30 minutes 2–3× daily Pulsatile None Identical to CJC-1295 No DAC. Same compound

The 30-minute half-life forces researchers into frequent dosing schedules if they want sustained GH elevation. A single morning injection of CJC-1295 No DAC will produce a measurable GH spike, but plasma GH returns to baseline within two hours. Meaning the compound exerts no influence for the remaining 22 hours of the day. Protocols designed around sustained GH exposure require dosing every 4–6 hours to maintain overlapping GH pulses.

This is why many researchers pair CJC-1295 No DAC with a GHRP (growth hormone-releasing peptide) like GHRP-2, GHRP-6, or ipamorelin. GHRPs act on the ghrelin receptor, which amplifies GH release synergistically when co-administered with a GHRH analog. The combination produces a larger, sharper GH pulse than either compound alone. And because both peptides have short half-lives, researchers maintain control over timing and frequency of GH elevation.

What If: CJC-1295 No DAC Scenarios

What If I Dose CJC-1295 No DAC Only Once Daily?

You'll see a single GH pulse lasting 90–120 minutes, followed by 22+ hours of baseline GH levels. The 30-minute half-life means the peptide is functionally cleared from circulation within two hours. After that, there's no residual GH-stimulating activity. If your protocol requires sustained GH elevation or multiple daily pulses, once-daily dosing is insufficient. Adjust to 2–3 injections spaced 4–6 hours apart.

What If I Accidentally Leave Reconstituted CJC-1295 No DAC Out of the Fridge Overnight?

Any temperature excursion above 8°C for more than 4–6 hours risks irreversible protein denaturation. The peptide may still appear clear and colourless, but the amino acid sequence has been compromised. Meaning reduced or absent biological activity. If the vial was left at room temperature (20–25°C) overnight, assume the batch is degraded and discard it. There's no reliable way to verify potency loss visually or via simple bench testing.

What If I Want Sustained GH Elevation Without Multiple Daily Injections?

Switch to CJC-1295 with DAC, which has a 6–8 day half-life and requires only 1–2 injections per week. The DAC modification binds the peptide to serum albumin, creating a sustained release mechanism that maintains tonic GH elevation rather than discrete pulses. The trade-off is loss of control over pulse timing. DAC creates continuous low-level stimulation, not the sharp peaks and troughs of the No DAC version.

The Unflinching Truth About CJC-1295 No DAC Half-Life Claims

Here's the honest answer: most online sources claiming CJC-1295 No DAC has a multi-day half-life are conflating it with the DAC-modified version or repeating manufacturer marketing that doesn't align with published pharmacokinetic data. The 30-minute half-life is not a supplier-specific variation. It's a direct consequence of the peptide's molecular structure. Without the DAC group, the peptide cannot bind albumin, and without albumin binding, it degrades rapidly via enzymatic cleavage.

The confusion is compounded by inconsistent naming conventions. CJC-1295 No DAC is chemically identical to Modified GRF (1-29) and sermorelin analog, but different suppliers use different labels. Some label Modified GRF (1-29) as 'CJC-1295 No DAC' explicitly; others list it as 'Mod GRF' without clarifying the CJC equivalence. This creates the false impression that these are distinct peptides with different half-lives. They're not. The active compound is the same, the half-life is the same, and the dosing requirements are the same.

If your protocol depends on long-acting GH stimulation, verify that the product includes the DAC modification before purchasing. Suppliers at Real Peptides clearly distinguish between DAC and No DAC variants in product specifications. This is not universal across the industry. A researcher ordering 'CJC-1295' without specifying DAC status may receive either version depending on supplier default listings, and the pharmacokinetic difference is not trivial.

Reconstitution and Dosing: Where Most Errors Occur

The 30-minute half-life doesn't begin until the peptide is injected. But the process of reconstituting lyophilised CJC-1295 No DAC introduces multiple failure points that can compromise potency before the peptide ever reaches the bloodstream. The most common mistake isn't contamination. It's injecting air into the vial while drawing the solution. The resulting pressure differential pulls contaminants back through the needle on every subsequent draw, even when using aseptic technique.

Proper reconstitution requires drawing bacteriostatic water into the syringe first, then injecting it slowly down the side of the vial rather than directly onto the lyophilised cake. Vigorous shaking denatures the protein structure. Swirl gently until the powder fully dissolves. Once reconstituted, the solution must be stored upright at 2–8°C in a dark environment (light exposure accelerates oxidative degradation). Each draw from the vial should use a fresh needle to prevent bacterial introduction.

Dosing consistency matters more with short-acting peptides than with long-acting analogs. A 10% variance in dose timing or concentration produces negligible effects when working with CJC-1295 with DAC (because the multi-day half-life smooths out minor deviations), but the same variance creates measurable pulse-to-pulse inconsistency with the No DAC version. Researchers relying on precise GH response curves must standardise injection time, dose volume, and administration site to reduce variability.

The 30-minute half-life of CJC-1295 No DAC is a feature, not a limitation. It mirrors the body's endogenous GHRH secretion pattern and allows for precise control over GH pulse timing. Understanding the pharmacokinetic difference between DAC and No DAC variants prevents protocol design errors, dosing mistakes, and misinterpretation of GH response data. Researchers working with GHRH analogs must verify the specific peptide modification, confirm storage conditions, and dose according to the compound's actual plasma kinetics. Not the marketing claims or assumption-based protocols that dominate online forums.

All compounds discussed on this page are sold for research use only and are not for human consumption.

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

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Questions

CJC-1295 No DAC has a plasma half-life of approximately 30 minutes, while the DAC-modified version has a half-life of 6–8 days. The DAC modification binds the peptide to serum albumin, creating a sustained-release mechanism that prevents rapid enzymatic degradation. Without DAC, the peptide circulates freely and is cleared from the bloodstream within 90–120 minutes, requiring multiple daily doses to maintain GH elevation.
CJC-1295 No DAC requires dosing 2–3 times per day to maintain pulsatile GH elevation. The 30-minute half-life means a single injection produces a GH spike lasting 90–120 minutes, after which plasma GH returns to baseline. Protocols requiring sustained GH activity space doses 4–6 hours apart to create overlapping pulses throughout the day.
No — reconstituted CJC-1295 No DAC must be refrigerated at 2–8°C and used within 28 days. Temperature excursions above 8°C for more than 4–6 hours cause irreversible protein denaturation, rendering the peptide inactive even if it appears clear and colourless. Lyophilised powder stored at −20°C remains stable for 12–24 months before reconstitution.
Yes — CJC-1295 No DAC and Modified GRF (1-29) are chemically identical peptides. The different naming conventions create confusion, but the amino acid sequence, half-life, and dosing requirements are the same. Both are GHRH analogs without the DAC modification, both have a 30-minute plasma half-life, and both require multiple daily doses.
The 30-minute half-life results from rapid enzymatic degradation by dipeptidyl peptidase-IV (DPP-IV) and other proteases in the bloodstream. Without the DAC modification, the peptide cannot bind to serum albumin — it circulates as a free molecule and is cleaved at the N-terminus within minutes. This mirrors the half-life of native GHRH, which is also pulsatile and short-lived.
Missing a dose simply eliminates one GH pulse from your protocol — there's no cumulative effect or rebound suppression because the peptide doesn't accumulate in the system. Resume your regular dosing schedule at the next planned injection time. Do not double-dose to compensate — that creates an abnormally large GH spike without extending the duration of GH elevation.
No — the 30-minute half-life ensures the peptide is cleared from systemic circulation within two hours after each injection. There's no plasma accumulation, no depot effect, and no residual activity between doses. Each injection produces an isolated GH pulse independent of previous administrations, which is why sustained protocols require multiple daily doses.
Yes, but it requires strict adherence to multiple daily dosing schedules. The short half-life means you must inject 2–3 times per day to maintain overlapping GH pulses throughout the study period. For protocols requiring sustained tonic GH elevation without frequent dosing, CJC-1295 with DAC (6–8 day half-life, 1–2 weekly injections) is the more practical choice.
Plasma half-life (30 minutes) refers to how long the peptide remains active in the bloodstream after injection. Storage stability (12–24 months lyophilised, 28 days reconstituted) refers to how long the peptide remains structurally intact before degradation under controlled conditions. These are separate processes — a peptide can have a short biological half-life and a long shelf life.
Co-administration with a GHRP (GHRP-2, GHRP-6, or ipamorelin) amplifies GH release synergistically by activating both the GHRH receptor (via CJC-1295 No DAC) and the ghrelin receptor (via GHRP). This combination produces a larger, sharper GH pulse than either compound alone. Because both peptides have short half-lives, researchers maintain precise control over pulse timing and amplitude.

RESEARCH USE ONLY · NOT EVALUATED BY THE FDA

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