CJC-1295: The Long-Acting GHRH Analogue — Complete Guide to Benefits, Dosing & Stacking

What Is CJC-1295?

CJC-1295 is a synthetic analogue of growth hormone-releasing hormone (GHRH) — the peptide your hypothalamus produces to signal the pituitary gland to secrete growth hormone (GH). Developed by ConjuChem Biotechnologies, CJC-1295 was engineered to address GHRH's central pharmacological weakness: native GHRH (1-29) is rapidly cleaved by dipeptidyl peptidase IV (DPP-IV) and has a plasma half-life of fewer than seven minutes.

CJC-1295 solves this problem through strategic amino acid substitutions that confer DPP-IV resistance, dramatically extending the peptide's active window. The result is a GHRH analogue that can meaningfully elevate GH and insulin-like growth factor 1 (IGF-1) over days rather than minutes — making it one of the most pharmacologically sophisticated peptides in use today.

It comes in two distinct forms that share the same base sequence but behave very differently in the body: CJC-1295 with DAC and CJC-1295 without DAC (also called Modified GRF 1-29 or Mod-GRF). Understanding this distinction is essential before selecting a protocol.

The DAC Modification: Engineering Extended Half-Life

The Drug Affinity Complex (DAC) is the defining feature of the long-acting version of CJC-1295. DAC is a chemical linker attached to the peptide's lysine residue that enables covalent binding to circulating serum albumin — the most abundant protein in human plasma.

Because albumin has a half-life of approximately 19 days, CJC-1295 DAC effectively "hitchhikes" on albumin's long circulatory lifespan. This produces a dramatic pharmacokinetic difference:

• CJC-1295 with DAC: Half-life of 5.8–8.1 days; active for up to 2 weeks after a single injection
• CJC-1295 without DAC (Mod-GRF 1-29): Half-life of 30–60 minutes; cleared within hours

A landmark 2006 study published in the Journal of Clinical Endocrinology & Metabolism by Ionescu and Frohman demonstrated that a single subcutaneous injection of CJC-1295 DAC produced dose-dependent increases in mean plasma GH concentrations of 2- to 10-fold lasting 6 or more days, and increases in mean plasma IGF-1 concentrations of 1.5- to 3-fold lasting 9–11 days. Crucially, pulsatile GH secretion was preserved — the peptide elevated baseline GH without blunting the natural rhythm of GH pulses.

Mechanism of Action

CJC-1295 exerts its effects through the GHRH receptor (GHRHR) on somatotroph cells of the anterior pituitary gland. When the peptide binds GHRHR, it activates adenylyl cyclase via Gs protein coupling, elevating intracellular cyclic AMP (cAMP). This cascade triggers two downstream effects:

1. Increased GH synthesis — cAMP upregulates transcription of the GH gene
2. Enhanced GH secretion — calcium influx through voltage-gated channels promotes GH vesicle exocytosis

The net effect is an increase in the amplitude of GH pulses without significant alteration of pulse frequency. This is physiologically distinct from supraphysiological GH administration (exogenous HGH), which suppresses endogenous GH axis feedback. CJC-1295 works with the pituitary, not around it — the gland retains control over secretion, it simply receives a stronger stimulatory signal.

Elevated GH then acts on the liver to stimulate IGF-1 production. IGF-1 mediates most of GH's anabolic and body composition effects, including muscle protein synthesis, lipolysis, and collagen production.

CJC-1295 with DAC vs. Without DAC: Which Should You Use?

This is the most common source of confusion with CJC-1295. The two versions are not interchangeable, and the choice between them has meaningful clinical implications.

CJC-1295 with DAC

The DAC version provides a continuous, sustained elevation in GH and IGF-1. Because the peptide remains active for days, it produces a constant rather than pulsatile GH stimulus. Some practitioners prefer this for anti-aging applications where steady IGF-1 elevation and simplicity of dosing (once or twice weekly) are priorities.

Typical dosing: 1,000–2,000 mcg (1–2 mg) subcutaneously once per week

Best for: Convenience, anti-aging, sustained body recomposition over months

CJC-1295 without DAC (Mod-GRF 1-29)

The no-DAC version has a short active window that allows it to be dosed in sync with the body's natural GH pulse rhythm. When injected, it produces a sharp GH pulse that clears within hours — closely mimicking the pattern of endogenous GHRH release. This is the version almost universally used in combination stacks with GH secretagogues like Ipamorelin.

Typical dosing: 100–200 mcg subcutaneously 1–3 times daily, timed to align with natural GH pulses (fasted morning, pre-workout, or before bed)

Best for: Stacking with Ipamorelin, preserving pulsatile GH physiology, athletes focused on performance and recovery

Benefits of CJC-1295

CJC-1295's benefits are downstream effects of elevated GH and IGF-1 activity. The evidence base includes both the original clinical trials and extensive real-world data from clinical use in anti-aging and functional medicine:

Body Composition

GH and IGF-1 promote lipolysis (fat breakdown) — particularly visceral and subcutaneous fat — while simultaneously supporting lean muscle mass retention and growth. In the Ionescu-Frohman trials, subjects showed measurable reductions in fat mass alongside preserved or increased lean body mass. These effects are gradual, with significant body composition changes typically emerging after 8–12 weeks of consistent use.

Recovery and Tissue Repair

Elevated IGF-1 accelerates protein synthesis in skeletal muscle and stimulates collagen production in connective tissue. Athletes and clinical users commonly report faster recovery from training, reduced DOMS (delayed onset muscle soreness), and improved healing from musculoskeletal injuries.

Sleep Quality

GH secretion is tightly coupled to slow-wave sleep (SWS) — the most restorative phase of the sleep cycle. Many users report that improved sleep depth is among the first and most consistent effects of CJC-1295 therapy, often appearing within the first 1–2 weeks. This is thought to reflect both the GH-promoting effect of the peptide and GH's reciprocal role in modulating sleep architecture.

Skin, Hair, and Anti-Aging

Collagen is the primary structural protein of skin, and GH/IGF-1 signaling is a key driver of collagen synthesis. Sustained elevation of these hormones over months is associated with improved skin elasticity, thickness, and hydration. Users also report improvements in hair quality and nail strength.

Cognitive and Well-Being Effects

GH receptors are expressed in the brain, and IGF-1 crosses the blood-brain barrier, exerting neuroprotective and neuroplasticity-promoting effects. Many users describe improved mood, mental clarity, and motivation — effects that are subjective but consistently reported in clinical contexts.

Dosing Protocols

CJC-1295 with DAC Protocol

• Dose: 1,000–2,000 mcg (1–2 mg) per injection
• Frequency: Once or twice weekly
• Timing: Any time of day; no need to time around meals
• Cycle length: 12–24 weeks, followed by a break of at least 4–8 weeks

CJC-1295 without DAC (Mod-GRF 1-29) Protocol

• Dose: 100–200 mcg per injection
• Frequency: 2–3 times daily
• Optimal timing windows:
  • Morning (fasted, before eating)
  • Pre- or post-workout
  • 30–60 minutes before bed
• Cycle length: 12–16 weeks, with 4–8 week breaks

For both versions, subcutaneous injection into abdominal fat is the standard route. Rotate injection sites to minimize lipodystrophy risk.

Stacking CJC-1295 with Ipamorelin

The CJC-1295 + Ipamorelin stack is one of the most well-established peptide combinations in clinical use. The rationale is mechanistic: these two peptides stimulate GH release through entirely different receptors.

• CJC-1295 (Mod-GRF) activates the GHRH receptor, increasing GH pulse amplitude
• Ipamorelin activates the ghrelin receptor (GHS-R1a), stimulating GH release through an independent pathway

The combination produces synergistic — not simply additive — GH release. Studies suggest the stack can generate 5–10x baseline GH compared to 2–3x for either agent alone. Ipamorelin also provides an important safety advantage: unlike GHRP-2 or GHRP-6, it is highly selective for GH release with minimal effects on cortisol or prolactin, making the combination both potent and well-tolerated.

Standard CJC-1295 + Ipamorelin Stack Protocol

• CJC-1295 no-DAC: 100–200 mcg per injection
• Ipamorelin: 100–200 mcg per injection
• Frequency: 2–3 times daily (morning, pre-workout or afternoon, and before bed)
• Administration: Injected simultaneously as a single subcutaneous dose

Some practitioners prefer to use CJC-1295 DAC (once weekly) combined with daily Ipamorelin, capturing the sustained IGF-1 elevation of the DAC version while using Ipamorelin's pulsatile GH stimulation for daily performance and recovery benefits.

Stacking with MK-677 (Ibutamoren)

MK-677 is an oral ghrelin mimetic that, like Ipamorelin, activates GHS-R1a. Some users combine CJC-1295 DAC with MK-677 for maximal convenience — weekly injections plus a daily oral agent. This combination can produce significant IGF-1 elevation but carries a higher risk of side effects including water retention, increased appetite, and elevated fasting glucose.

Side Effects and Safety Considerations

CJC-1295 has demonstrated a favorable safety profile in clinical trials, with most subjects experiencing minimal adverse effects. That said, several side effects are worth knowing:

Common Side Effects

• Injection site reactions: Mild redness, itching, or transient swelling at the injection site — the most commonly reported adverse effect
• Water retention: Particularly in the first 2–4 weeks as GH levels rise. Presents as facial puffiness or mild swelling in extremities. Generally resolves with continued use as the body adapts
• Tingling or numbness: Sometimes described as a transient pins-and-needles sensation, particularly in hands and feet, related to fluid shifts
• Fatigue or headache: Occasionally reported, especially in the early phase

Less Common Side Effects

• Joint discomfort: GH-related fluid retention can temporarily increase pressure around joints
• Elevated fasting glucose: GH has counter-regulatory effects on insulin sensitivity; this is generally mild with physiological dosing but warrants monitoring in individuals with metabolic concerns
• Flushing: A brief warmth or redness, typically mild and short-lived

Cortisol and Selectivity

Unlike older GHRP compounds such as GHRP-2 and GHRP-6, CJC-1295 stimulation is selective for GH release. It does not meaningfully affect cortisol or prolactin, which contributes to its clinical safety profile. When stacked with Ipamorelin (also highly selective), this advantage is preserved.

Legal and Regulatory Status

CJC-1295 occupies a complex regulatory position in the United States. It is not FDA-approved for any indication and has no approved commercial formulation. Its only legal pathway for human use is through compounding pharmacies operating under 503A or 503B regulations.

In 2024, the FDA proposed placing CJC-1295 and several other peptides in a "Category 2" classification under 503A bulk drug substances — a designation that would significantly restrict compounding of these agents. However, legal challenges from compounding pharmacy associations have suspended enforcement, leaving the landscape in flux as of 2026.

In practical terms, CJC-1295 can be prescribed by licensed physicians and compounded by accredited 503A pharmacies for individual patients. It cannot be sold as a dietary supplement or over-the-counter product. Research-grade CJC-1295 sold by peptide vendors is technically for laboratory research use only and is not intended for human administration.

Outside the US, regulatory status varies widely. The UK, Australia, and Canada have their own frameworks governing compounded peptides, and availability through licensed practitioners is possible but subject to local rules.

Timeline: What to Expect

• Weeks 1–2: Improved sleep depth and quality is often the first noticeable effect. Some users report mild water retention during this phase
• Weeks 3–6: Recovery from training improves; energy and mood may noticeably improve
• Weeks 8–12: Body composition changes become visible — leaner appearance, gradual muscle fullness
• Months 3–6: Skin quality, hair, and connective tissue improvements become more pronounced; IGF-1 levels measurably elevated on bloodwork

Reconstitution and Storage

CJC-1295 is supplied as a lyophilized (freeze-dried) powder. To reconstitute:

1. Add bacteriostatic water (BAC water) slowly to the vial using a sterile syringe — typically 1–2 mL depending on vial size
2. Swirl gently; do not shake vigorously, as agitation can degrade the peptide
3. Once reconstituted, store immediately at 2–8°C (standard refrigerator)
4. Use within 28 days of reconstitution

Lyophilized (unreconstituted) vials can be stored at room temperature for short periods, but long-term storage should be at -20°C. Research has shown that reconstituted CJC-1295 left at room temperature for 12+ hours loses up to 38% of potency — refrigeration after reconstitution is non-negotiable.

Is CJC-1295 Right for You?

CJC-1295 is best suited for adults who have established a clinical relationship with a knowledgeable practitioner and have confirmed suboptimal GH/IGF-1 status via bloodwork. It is most commonly used in contexts including:

• Anti-aging and longevity medicine protocols
• Body recomposition alongside resistance training
• Recovery from injury, particularly connective tissue and musculoskeletal injuries
• Sleep optimization as part of a broader wellness protocol

It is not appropriate for individuals under 25 (whose GH axis is still active), pregnant or breastfeeding individuals, those with active malignancy, or individuals with untreated hypothyroidism or other pituitary disorders.

If you're weighing CJC-1295 against standalone Ipamorelin or an oral secretagogue like MK-677, the right choice depends on your goals, dosing preferences, and access to compounding pharmacy support. Our guide to Ipamorelin and our MK-677 guide provide the detailed comparisons you need to make that decision confidently.

The Bottom Line

CJC-1295 is one of the best-characterized peptide therapies in the GHRH analogue class. Its clinical trial evidence is unusually robust for a compounded peptide — with a published human dose-escalation study demonstrating sustained, dose-dependent GH and IGF-1 elevation over days to weeks. The DAC modification represents genuine pharmaceutical engineering: a half-life transformation from minutes to days that makes it the only GHRH analogue offering once-weekly convenience.

When used appropriately — with physician oversight, quality compounding, and realistic timelines — CJC-1295 represents a sophisticated approach to growth hormone optimization that works with the body's own pituitary physiology rather than replacing it.