CJC-1295 — Research Reference
CJC-1295 is a synthetic analogue of growth hormone-releasing hormone (GHRH), the hypothalamic peptide that signals the pituitary gland to secrete growth hormone. It is available in two distinct forms that differ fundamentally in pharmacokinetics: CJC-1295 with DAC and CJC-1295 without DAC (also known as Mod GRF 1-29). Understanding this distinction is critical when interpreting research protocols, as the two forms are not interchangeable.
Quick Reference
| Parameter | CJC-1295 with DAC | CJC-1295 without DAC (Mod GRF 1-29) |
|---|---|---|
| Amino acids | 30 (modified) | 29 (modified) |
| Half-life | ~7 days (reported) | ~30 minutes (reported) |
| Common reported doses | 1–2 mg per week | 100–300 mcg per injection |
| Dosing frequency | Once weekly | 2–3× daily, around training/sleep |
| Administration | Subcutaneous | Subcutaneous |
| Storage (lyophilized) | Refrigerator preferred | Refrigerator preferred |
| Storage (reconstituted) | Refrigerated; 4–6 weeks | Refrigerated; 4–6 weeks |
Overview
CJC-1295 is a modified 30-amino-acid peptide that extends the sequence of natural GHRH (1-29) with stabilising substitutions to resist enzymatic degradation. Two forms exist:
CJC-1295 with DAC incorporates a Drug Affinity Complex (DAC) — a technology that covalently binds the peptide to circulating albumin via a maleimide linkage. This dramatically extends the effective half-life from minutes to approximately 7 days, enabling once-weekly dosing. The sustained elevation of GHRH signalling produces a prolonged increase in GH pulse amplitude and IGF-1 levels rather than discrete pulsatile GH peaks.
CJC-1295 without DAC (Mod GRF 1-29) lacks the albumin-binding modification and has a half-life of approximately 15–30 minutes. This produces a discrete GH pulse that mimics the natural pulsatile pattern more closely. It is the form typically described in combination with ipamorelin in anecdotal research protocols.
Research has investigated CJC-1295 for its potential role in:
- Amplifying growth hormone pulse amplitude and frequency
- Elevating circulating IGF-1 levels
- Supporting muscle tissue preservation and anabolism
- Promoting fat oxidation
- Enhancing recovery and sleep quality
CJC-1295 is not approved for human therapeutic use in any major jurisdiction, is classified as a research chemical, and appears on the WADA Prohibited List.
Reported Protocols
The following information represents commonly reported research ranges drawn from anecdotal accounts and available research literature. These are not medical recommendations.
CJC-1295 with DAC
Due to its long half-life, CJC-1295 with DAC is administered at infrequent intervals.
- Commonly reported dose: 1–2 mg subcutaneously, once per week
- Mechanism note: Because the DAC form maintains sustained GHRH receptor stimulation, it blunts the pulsatile nature of GH release. Some researchers prefer this for sustained IGF-1 elevation; others prefer the pulsatile approach of the non-DAC form
- Duration: Commonly reported cycles of 8–16 weeks
CJC-1295 without DAC (Mod GRF 1-29)
- Commonly reported dose: 100–300 mcg per injection, administered 2–3 times daily
- Combination with ipamorelin: This is the most widely reported protocol. CJC-1295 without DAC (100–200 mcg) and ipamorelin (100–300 mcg) are injected simultaneously, targeting both the GHRH receptor and the ghrelin receptor to produce a synergistic GH pulse
- Timing: Anecdotal protocols frequently describe injection in a fasted state, before sleep, and optionally around training sessions — mirroring the natural contexts of GH release
- Duration: Commonly reported cycles range from 8 to 16 weeks
Labelling Caution
Researchers should note that the terms “CJC-1295” and “Mod GRF 1-29” are not standardised across all commercial research sources. Some suppliers label Mod GRF 1-29 as CJC-1295 without further specification. Verifying the formulation — with or without DAC — before use is important for protocol planning.
Reported Effects
The following effects have been reported in preclinical research and anecdotal accounts. This list reflects the research landscape, not confirmed clinical outcomes.
Growth Hormone and IGF-1 Elevation
Clinical research on CJC-1295 with DAC has demonstrated sustained elevation of serum GH and IGF-1 following administration. A published clinical study reported 2- to 10-fold increases in mean 24-hour GH concentrations and sustained IGF-1 elevation for up to two weeks following a single injection.
Muscle Growth and Body Composition
Research has investigated GHRH analogues for their potential role in supporting lean tissue preservation and anabolism via elevated IGF-1. Anecdotal reports frequently describe improvements in muscle fullness, strength, and body composition over extended cycles.
Fat Loss
Research has investigated the role of elevated GH in lipolysis. Anecdotal accounts frequently describe gradual fat loss, particularly in the abdominal region, over extended cycles of 12+ weeks.
Recovery and Sleep
Anecdotal reports describe improvements in recovery from training and injury, as well as improvements in sleep quality and depth — consistent with the reported role of GH in tissue repair and sleep architecture.
Reported Side Effects
Reported side effects in research and anecdotal accounts include the following. This list does not constitute a comprehensive safety profile.
| Side Effect | Frequency Reported |
|---|---|
| Injection site redness or mild pain | Common |
| Transient flushing or warmth | Occasionally reported after injection |
| Headache | Occasionally reported |
| Water retention | Occasionally reported, particularly with DAC form |
| Tingling or numbness | Occasionally reported at higher doses |
| Transient hypoglycaemia | Rare; associated with post-injection GH surge |
Note on the DAC form: The sustained GH elevation produced by CJC-1295 with DAC means that side effects related to elevated GH (water retention, joint discomfort, insulin resistance) may be more pronounced or persistent compared to the pulsatile non-DAC form.
The compound has not undergone comprehensive human safety trials in a research chemical context.
Storage & Handling
Lyophilized Powder (Unreconstituted)
- Room temperature: Reported stable for up to 3 months when kept away from light and moisture
- Refrigerator (2–8°C): Preferred for extended storage; commonly reported stable for 12 months or more
- Freezer: Acceptable for long-term storage; avoid repeated freeze-thaw cycles
- Light sensitivity: Store in an opaque or amber vial; avoid direct light exposure
Reconstituted Solution
- Refrigerator (2–8°C): Use within 4–6 weeks of reconstitution
- Do not freeze a reconstituted solution
- Bacteriostatic water (BAC water) is the standard diluent for multi-use vials
- Discard if the solution becomes cloudy, discoloured, or shows particulate matter
Reconstitution
Add bacteriostatic water slowly along the inside wall of the vial. Swirl gently — do not shake. See the Reconstitution Guide for step-by-step instructions.
Frequently Asked Questions
What is the difference between CJC-1295 with DAC and without DAC? The DAC (Drug Affinity Complex) modification allows CJC-1295 to bind albumin in the bloodstream, extending the half-life from ~30 minutes to approximately 7 days. CJC-1295 with DAC produces a sustained, blunted elevation in GH and IGF-1. CJC-1295 without DAC (Mod GRF 1-29) produces a discrete GH pulse mirroring the natural pulsatile pattern. The two forms serve different research purposes and are not interchangeable.
Which form is better, with or without DAC? This is a subject of ongoing debate in the research community. Researchers seeking sustained IGF-1 elevation with once-weekly dosing may prefer the DAC form. Researchers seeking a pulsatile GH release pattern — particularly when combining with ipamorelin — typically use the non-DAC form (Mod GRF 1-29). Neither approach has been comprehensively evaluated in human trials.
Why is ipamorelin often combined with CJC-1295? Ipamorelin acts at the ghrelin receptor; CJC-1295 acts at the GHRH receptor. The two signalling pathways independently trigger GH secretion from different pituitary cell populations, and combined activation is reported in anecdotal accounts to produce a synergistic GH pulse larger than either compound alone.
How does CJC-1295 differ from sermorelin? Sermorelin is the unmodified GHRH 1-29 sequence with a very short half-life (~10–20 minutes). CJC-1295 incorporates amino acid substitutions that resist enzymatic degradation, extending the half-life. The DAC modification extends it further. Sermorelin is approved as a pharmaceutical in some jurisdictions; CJC-1295 is classified as a research chemical.
Related Pages
Goals: Muscle Growth · Performance
Class: GHRH Analogues
Comparisons: Ipamorelin vs CJC-1295 · CJC-1295 vs Sermorelin
Stacks: CJC-IPA
References & Further Reading
- Ionescu M, Frohman LA. (2006). Pulsatile secretion of growth hormone (GH) persists during continuous stimulation by CJC-1295, a long-acting GHRH analog. Journal of Clinical Endocrinology & Metabolism, 91(12), 4792–4797. PubMed →
- Jetté L, et al. (2005). hGRF1-29-albumin bioconjugates activate the GRF receptor on the anterior pituitary in rats. Endocrinology, 146(7), 3052–3058. PubMed →
- Walker RF. (2006). Sermorelin: a better approach to management of adult-onset growth hormone insufficiency? Clinical Interventions in Aging, 1(4), 307–308. PubMed →