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GHRH Analogue · DAC Modified Long-Acting GH Secretagogue

CJC-1295

DAC:GRF · Drug Affinity Complex GRF · Long-Acting GHRH

"A single injection that sustains elevated growth hormone for nearly a week. The convenience-first GHRH analogue — one or two injections weekly instead of three daily. The tradeoff: less physiological, harder to control if problems arise."

Type
GHRH analogue · albumin-binding DAC
Half-life
6–8 days (DAC version)
Status
UK: not illegal to buy or possess · WADA: prohibited at all times · US FDA: not approved · research compound
Phase II trial
2–10× GH elevation · sustained 6 days
Protocol summary
Dose (DAC)
1–2 mg weekly
Route
SubQ
Cycle
8–16 weeks, then break
Community-reported
1–2 mg/week SubQ (DAC version) · 8–16 week cycles
Often stacked with Ipamorelin for synergistic GH release
How we read the evidence
Published Phase 1 data · Phase 2 halted in 2006 · long-acting GHRH analog · widely used in community despite no FDA pathway
Animal evidence

GHRH-mimetic mechanism is well-characterised. CJC-1295 is a 30-amino-acid GHRH analog modified for stability; the DAC (Drug Affinity Complex) version covalently binds albumin, extending half-life from minutes to days. Animal work (Alba et al. 2006) showed once-daily CJC-1295 normalised growth in GHRH knockout mice, validating the mechanism.

Community & clinical practice

Two distinct community protocols depending on the version. CJC-1295 with DAC: 1–2 mg SubQ once weekly for sustained GH/IGF-1 elevation — the long half-life is the whole point. CJC-1295 without DAC (Mod-GRF 1-29): 100–200 mcg SubQ 2–3× daily, paired with a GHRP like Ipamorelin to mimic natural pulsatile GH release. The no-DAC stack is the more popular protocol because it preserves physiological pulsing; DAC version produces a flatter elevated baseline. Cycle 8–16 weeks then break 4+ weeks for either version — chronic stimulation downregulates pituitary response.

Human trial data

Phase 1 published in Journal of Clinical Endocrinology and Metabolism (Teichman et al. 2006) — single CJC-1295 DAC injection raised plasma GH 2–10 fold for 6+ days and IGF-1 1.5–3 fold for 9–11 days, with estimated half-life 5.8–8.1 days. Effects were dose-dependent. Phase 2 trial in HIV lipodystrophy was halted in 2006 after a participant death — attending physicians attributed the death to pre-existing coronary artery disease rather than the study drug, but the program was discontinued as a precaution. No further pharma development since.

Regulatory status

Not FDA-approved. No active approval pathway. WADA-banned for tested athletes. Sourcing is via research-peptide vendors. The 2006 Phase 2 halting is rarely mentioned in community marketing — Pep IQ flags it explicitly because it is part of the honest evidence picture, even though the death was not attributed to the drug.

Convergence

CJC-1295 has solid Phase 1 pharmacokinetic data and a clean mechanism (GHRH analog, dose-dependent GH/IGF-1 elevation). The Phase 2 halting in 2006 is a real signal even if the death was not directly attributed — pharma development stopped there. Community use is widespread with the standard protocols (DAC 1–2 mg weekly, or no-DAC 100–200 mcg 2–3× daily paired with Ipamorelin) running 8–16 weeks then breaking. No long-term human safety data for chronic use beyond Phase 1 timeframes — this is genuinely uncharted territory and Pep IQ flags it as such.

Origin & Background

The long-acting GHRH analogue

CJC-1295 with DAC is a GHRH analogue with a Drug Affinity Complex (DAC) — a chemical modification that enables the peptide to covalently bind to albumin in the bloodstream. Albumin is the most abundant plasma protein and has a half-life of approximately 19 days. By hitching a ride on albumin, CJC-1295 is slowly released over 6–8 days from a single injection, producing sustained GH stimulation far longer than any other GHRH analogue.

It was studied in a pivotal 2006 Phase II clinical trial (Teichman et al., Journal of Clinical Endocrinology & Metabolism) that remains the most cited evidence for any GHRH analogue. The trial in healthy adults showed dose-dependent GH increases of 2–10 fold lasting 6 days, and IGF-1 elevations lasting 9–11 days. After multiple doses, IGF-1 remained elevated for up to 28 days. No serious adverse events were reported at doses of 30–60 mcg/kg.

Despite this clinical data, CJC-1295 with DAC was not developed further as a pharmaceutical — likely due to the concerns about sustained non-pulsatile GH elevation and the commercial landscape. It became a research compound widely used in functional medicine, anti-ageing clinics, and the biohacking community, typically combined with ipamorelin.

DAC vs no-DAC — the fundamental difference: CJC-1295 with DAC and Mod-GRF 1-29 (CJC-1295 without DAC) are completely different in pharmacokinetics despite sharing the same base peptide. DAC = weekly dosing, sustained continuous GH elevation, less physiological. No-DAC = daily/multiple daily dosing, pulsatile GH, more physiological. Knowing which version you have is essential — they are not interchangeable.

Science & Mechanism

Albumin binding extends everything

Mechanism of Action

1
GHRHR binding: The base GHRH peptide binds to GHRH receptors on pituitary somatotrophs, activating adenylate cyclase and stimulating GH synthesis and release — identical mechanism to sermorelin and Mod-GRF.
2
Albumin covalent binding (DAC): The DAC modification creates a maleimide reactive group that covalently binds to cysteine-34 on albumin after injection. This creates a large albumin-peptide complex that resists renal filtration and proteolytic degradation, extending half-life to 6–8 days.
3
Sustained GH elevation: Rather than a discrete pulse, CJC-1295 DAC produces continuous, low-grade GH stimulation throughout the week. GH levels remain above baseline for the full dosing interval — unlike natural GH which pulses every few hours and falls to baseline between pulses.
4
Synergy with ipamorelin: Even on a background of continuous CJC-1295 GH elevation, adding ipamorelin creates additional sharp GH spikes through the independent ghrelin receptor. The 3–5x synergistic amplification documented for Mod-GRF also applies when ipamorelin is added to the CJC-1295 DAC baseline.
5
IGF-1 cumulative elevation: With weekly dosing, IGF-1 accumulates above baseline throughout the dosing period and can remain elevated for up to 28 days with repeated dosing. This produces the body composition effects of chronically elevated GH/IGF-1 — more consistent but less physiological than pulsatile alternatives.

The Phase II trial (Teichman 2006, n=64 healthy adults) is the best clinical evidence for any GHRH analogue outside of tesamorelin. At 30 and 60 mcg/kg doses, mean GH was elevated 2–10 fold for 6 days post-injection. IGF-1 rose 1.5–3 fold and remained elevated 9–11 days. After multiple doses, mean IGF-1 stayed above baseline for 28 days. This evidence is what separates CJC-1295 DAC from many research peptides — it has human pharmacokinetic and pharmacodynamic data from a proper clinical trial.

DAC vs No-DAC Comparison

Choosing between the two versions

CJC-1295 with DAC
Half-life6–8 days
Dosing1–2x weekly
GH patternContinuous baseline elevation
Side effect controlSlow to resolve (days)
Physiological?Less — non-pulsatile
Best forConvenience, adherence
Clinical dataPhase II RCT (2006)
Mod-GRF 1-29 (no DAC)
Half-life~30 minutes
Dosing2–3x daily
GH patternDiscrete pulses
Side effect controlRapid — hours to clear
Physiological?More — mimics natural rhythm
Best forControl, precision
Clinical dataMechanistic only

The practical verdict: If you will reliably inject 2–3 times daily and want maximum physiological accuracy, Mod-GRF 1-29 is the better choice. If adherence to frequent dosing is a challenge, CJC-1295 with DAC produces comparable GH/IGF-1 elevation with once or twice weekly injections — at the cost of less control and less pulsatile physiology. Most clinic protocols now favour Mod-GRF + ipamorelin for its controllability, but CJC DAC remains widely used for convenience.

Benefits & Evidence

What the data shows

📈
GH and IGF-1 elevation — best clinical evidence
Teichman Phase II (2006): 2–10x GH elevation lasting 6 days per injection; IGF-1 elevation 1.5–3x lasting 9–11 days; cumulative IGF-1 above baseline for 28 days with repeated dosing. The most robust human pharmacokinetic evidence of any GHRH analogue outside tesamorelin.
● Strong — Phase II RCT in healthy adults
💪
Body composition (via sustained GH/IGF-1)
Chronic GH/IGF-1 elevation drives protein synthesis, lipolysis, and lean mass accrual. Body composition changes emerge over 3–6 months of consistent use and are among the most reported benefits in both community and clinical contexts.
● Moderate — extrapolated from GH axis literature
🔁
Recovery and sleep quality
Sustained GH/IGF-1 elevation supports tissue repair and deep sleep quality. Users consistently report faster recovery between training sessions and improved sleep depth — effects that emerge within the first few weeks of use.
● Moderate — consistent community reports
🗓️
Dosing convenience
Once or twice weekly injection versus 2–3 times daily for Mod-GRF. For people who travel, work irregular hours, or struggle with frequent injection adherence, this is a meaningful practical advantage that directly affects real-world outcomes.
● Practical advantage — not a clinical evidence category
Things to know

Risks & considerations

⚠️
The primary safety concern unique to the DAC version is the slow clearance. With Mod-GRF, stopping an injection means the peptide is gone in 30 minutes. With CJC-1295 DAC, if you develop water retention, joint pain, or elevated IGF-1, you cannot rapidly stop the effect — you are committed to 6–8 days of exposure per injection. This fundamentally changes the risk-management calculus.
Moderate
Water retention and oedema — the most common side effect. Sustained IGF-1 causes sodium retention. More pronounced and more persistent than with Mod-GRF due to the longer half-life. Dose reduction is the fix — but takes days to work.
Moderate
Joint discomfort and carpal tunnel symptoms — another IGF-1 mediated effect. Dose-dependent. More common at higher weekly doses (2mg+). Resolves with dose reduction but slowly.
Moderate
Elevated IGF-1 — chronic sustained IGF-1 elevation is the theoretical long-term risk. Monitor every 3 months. Keep within age-appropriate reference ranges. The sustained elevation profile of CJC DAC may produce higher average IGF-1 than pulsatile alternatives.
Moderate
Potential receptor desensitisation — continuous GHRH receptor stimulation may lead to downregulation over time. This is the theoretical basis for cycling (12–16 weeks on, 4–8 weeks off) and is one reason practitioners increasingly prefer the pulsatile Mod-GRF approach.
Serious
Contraindicated in active malignancy — as with all GH-axis compounds. The sustained IGF-1 elevation from CJC DAC makes this contraindication particularly important.

⚠ Key Warnings

Start at 1mg weekly, not 2mg. The sustained half-life means you live with side effects for a week if you overdose. Conservative starting doses allow calibration before committing to higher doses.
Monitor IGF-1, fasting glucose and HbA1c every 3 months. More critical with the DAC version due to sustained elevation.
WADA prohibited at all times for competitive athletes.
Always inject fasted — insulin suppresses GH release even with the long-acting version.
Do not confuse with Mod-GRF 1-29 (CJC-1295 without DAC) — they have completely different half-lives and dosing protocols.