CJC-1295 no-DAC (Mod GRF 1-29)
Preclinical ResearchModified GRF (1-29) / CJC-1295 without DAC
The short-acting GHRH analog commonly sold under the CJC-1295 name. Without the DAC moiety its half-life is roughly 30 minutes, producing a sharp GH pulse rather than sustained elevation.
Dose
100 mcg
Route
Subcutaneous injection
Cycle
8-12 weeks
Storage
Store at 2°C to 8°C (36°F to 46°F) protected from light, or below -20°C (-4°F) for long-term storage.
What is CJC-1295 no-DAC (Mod GRF 1-29)?
CJC-1295 no-DAC, also known as Mod GRF 1-29 or Sermorelin-modified, is a synthetic analog of Growth Hormone Releasing Hormone (GHRH). It consists of the first 29 amino acids of endogenous GHRH with specific modifications to enhance its stability and biological activity. The key modification is the replacement of the second amino acid with D-Alanine, which makes it resistant to degradation by the enzyme dipeptidyl peptidase-IV (DPP-IV). Unlike its longer-acting counterpart, CJC-1295 with DAC (Drug Affinity Complex), Mod GRF 1-29 does not contain the DAC moiety, resulting in a significantly shorter half-life of approximately 30 minutes. This short half-life causes it to elicit a more pulsatile release of growth hormone (GH) from the pituitary gland, mimicking the natural physiological secretion of GHRH. This pulsatile release is often preferred in research settings when attempting to maximize synergy with GH-releasing peptides (GHRPs) like Ipamorelin or GHRP-2/6, as it provides discrete GH pulses rather than a sustained elevation.
Key Benefits
- Short GH pulse
- Pairs with GHRPs
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Molecular Information
Molecular weight
3367.9 g/mol
Length
29 amino acids
Type
Growth Hormone Releasing Hormone (GHRH) Analog
Amino acid sequence
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-NH2
This sequence represents a modified GRF (1-29) peptide. The D-Alanine substitution at position 2 (Tyr-D-Ala) is a key modification that increases resistance to enzymatic degradation, specifically by dipeptidyl peptidase IV (DPP-IV), compared to natural GHRH.
Pharmacokinetics
Time to peak
Approximately 5-10 minutes
Half-life
0.5 h
Time to clear
Within 30-60 minutes
Thorner, M. O., et al. (2007). 'The effect of a single dose of CJC-1295, a long-acting growth hormone-releasing hormone analog, on the GH-IGF-I axis in healthy subjects.' Journal of Clinical Endocrinology & Metabolism, 92(1), 86-91.
Research Indications
Stimulation of Endogenous GH Release
Mod GRF 1-29 acts as a GHRH analog, binding to pituitary GHRH receptors to stimulate a pulsatile release of growth hormone. This effect has been well-documented in animal studies and smaller human studies.
Synergistic GH Release with GHRPs
Research, including human studies, demonstrates that co-administration of Mod GRF 1-29 with a Growth Hormone Releasing Peptide (GHRP) such as Ipamorelin or GHRP-2 results in a significantly greater, often synergistic, release of GH compared to either peptide alone. This is attributed to their distinct mechanisms of action (GHRH receptor vs. ghrelin receptor).
Research Protocols
| Goal | Dose | Frequency | Route |
|---|---|---|---|
| Acute Growth Hormone Pulsatility | 50-100 mcg | 1-2 times daily | Subcutaneous |
| Synergistic GH Release (with GHRP) | 50-100 mcg | 2-3 times daily (concurrently with GHRP) | Subcutaneous |
| Enhanced Recovery / Body Composition (Long-term) | 100 mcg | 1-3 times daily | Subcutaneous |
| Investigating GH Secretagogue Effects | 1 mcg/kg | Single dose or daily | Subcutaneous |
Mod GRF 1-29 is most effective when administered at times when natural GH release is typically high (e.g., before sleep) or when GHRPs are also being used. Administration on an empty stomach is generally recommended to avoid interaction with nutrient-induced insulin spikes, which can blunt GH release.
Peptide Interactions
- Synergistic
GHRP-2, GHRP-6, Ipamorelin
These Growth Hormone Releasing Peptides (GHRPs) stimulate GH release via ghrelin receptors, a mechanism distinct from Mod GRF 1-29's action on GHRH receptors. Their co-administration often leads to a synergistic increase in GH release, observed in human studies.
- Use Caution
Somatostatin (Growth Hormone Inhibiting Hormone)
Somatostatin inhibits GH release. While Mod GRF 1-29 acts to overcome somatostatin's inhibitory effects, very high endogenous or exogenous somatostatin levels could blunt the efficacy of Mod GRF 1-29. This is an inherent physiological feedback mechanism.
- Monitor Combination
Insulin
High insulin levels (e.g., after a high-carbohydrate meal) can acutely blunt growth hormone secretion. Administering Mod GRF 1-29 on an empty stomach is generally recommended to maximize its effect. While not a direct interaction, timing is important.
- Use Caution
Glucocorticoids (e.g., Cortisol, Dexamethasone)
Prolonged or high doses of glucocorticoids can suppress pituitary GH secretion and reduce the responsiveness to GHRH. This may reduce the effectiveness of Mod GRF 1-29. This is documented in clinical literature regarding GH suppression.
- Compatible
Thyroid Hormones
Thyroid hormones are essential for normal growth hormone synthesis and secretion. Optimal thyroid function is generally supportive of GHRH efficacy.
How to Reconstitute
- 1Carefully remove the cap from the lyophilized peptide vial.
- 2Swab the rubber stopper with an alcohol wipe and allow it to air dry.
- 3Using a sterile syringe, draw the desired amount of bacteriostatic water (typically 1-2 mL) and inject it slowly down the side of the peptide vial, avoiding direct contact with the powder.
- 4Do not shake the vial. Gently swirl or roll the vial between your palms until the powder is completely dissolved. This may take a few minutes.
- 5Once dissolved, the solution should be clear. If particles are visible, do not use the solution.
Reconstitution should be performed carefully to avoid agitation of the peptide solution, which can degrade the peptide. Use bacteriostatic water for injection.
What to Expect
- Pulsatile release of growth hormone from the pituitary gland, detectable shortly after injection.
- Potentially enhanced efficacy when stacked with a growth hormone-releasing peptide (GHRP) for synergistic GH release.
- Improved sleep quality in some animal models and anecdotal human research reports.
- Potential for mild, temporary localized reactions at the injection site (e.g., redness, itching).
- Increased levels of Insulin-like Growth Factor 1 (IGF-1) observed after consistent, longer-term administration.
- Subjective reports in animal and some human studies of improved body composition over several weeks or months.
Side Effects & Safety
- Research indicates Mod GRF 1-29 stimulates the body's natural GH production. Consult peer-reviewed literature to understand potential impacts on endogenous hormone regulation.
- Potential for minor injection site reactions such as redness, itching, or soreness. Rotate injection sites to minimize irritation.
- Animal studies suggest GHRH analogs might potentially stimulate the growth of existing tumors. This is a theoretical concern; however, research should proceed with caution in subjects with a history of cancer.
- Some human research reports indicate transient increases in prolactin levels; however, this is generally less common and less pronounced than with some GHRPs.
- As with all injectable peptides, maintaining strict aseptic technique during reconstitution and administration is crucial to prevent infection.
- Research subjects should be monitored for any signs of allergic reaction, though such events are rare with GHRH analogs.
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