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CJC-1295 / Mod-GRF (1-29)

A modified GHRH analog for boosting growth hormone release, almost always stacked with a GHRP like Ipamorelin. The 'without DAC' version (Mod-GRF) sees far more use than the long-acting DAC version.

Research chemical Fitness & muscle

Reviewed 2026-09-12
Full name
Modified Growth Hormone Releasing Factor (1-29), with or without Drug Affinity Complex (DAC)
Also known as
Mod-GRF (1-29), CJC-1295 without DAC, CJC-1295 with DAC
Regulatory status
Research chemical, not FDA-approved for any indication. GHRH analogs as a class have approved relatives (e.g. tesamorelin) but CJC-1295/Mod-GRF specifically has not gone through human drug trials.
Variant note
Not to be confused with 'CJC-1295 with DAC' (see the separate page for that long-acting, albumin-binding variant) — the two are pharmacokinetically distinct compounds with different half-lives and dosing frequency, despite the similar name.

Origin

A synthetically modified fragment of growth hormone releasing hormone (GHRH). The DAC version has a Drug Affinity Complex attached that binds serum albumin, extending half-life from minutes to roughly a week. The far more commonly used version without DAC, technically Mod-GRF 1-29, behaves like a short-acting GHRH lasting about 30 minutes, which better suits the pulsatile dosing pattern users are trying to replicate.

Mechanism

GHRH analogs increase the number and sensitivity of pituitary cells that respond to a co-administered GHRP like Ipamorelin, amplifying the GH pulse those compounds produce. The two classes are meant to be used together, not alone, since they act on complementary parts of the GH release pathway.

Research summary

Evidence

Human data is limited mostly to older, small pharmacokinetic and pharmacodynamic studies of the underlying GHRH(1-29) sequence, not dedicated trials of the modified compounds sold today. The DAC-bearing long-acting version has drawn more safety concern in self-experimentation circles: prolonged, less-controllable elevation of GH/IGF-1 and a higher rate of reported adverse reactions than the short-acting Mod-GRF version. Most experienced users and harm-reduction guides now favor Mod-GRF over CJC-1295 with DAC.

Evidence tier: Research chemical — see the methodology note for how this is assessed.

Citations

Reported benefits

  • Improved sleep quality (commonly reported, consistent with GH's normal role in sleep architecture)
  • Modest reported improvements in recovery and body composition when combined with a GHRP and resistance training
  • Considered a cost-effective way to amplify the GH pulse from a GHRP like Ipamorelin rather than a strong standalone compound

Dosing protocols reported in the literature & community

These are protocols reported by compounding pharmacies, published trials, or self-experimentation communities — not a prescription. Start low, especially for anything new.

Reported dosing protocols
RouteReported protocol
Subcutaneous injection (Mod-GRF, without DAC) — the generally preferred versionCommonly cited compounding-pharmacy protocol: 200 mcg once daily, 5x/week, paired with a GHRP. Many experienced self-experimenters use notably lower doses — around 100 mcg or less — arguing that higher doses increase GH only marginally further while adding cost and side-effect risk. Nobody in harm-reduction-focused communities recommends exceeding 100 mcg per injection.
TimingStandard advice is to inject in a fasted state (2-3 hours after eating, avoiding food for 30 minutes after), commonly before bed and/or immediately on waking, to align with the body's natural pulsatile GH release windows and avoid insulin blunting the GH pulse.

Side effects

  • Flushing, hot skin, itchiness reported especially at higher doses — treated by cautious users as an early warning sign to reduce dose, not a benign sign of 'working'
  • Heart palpitations reported at higher doses — a stop-and-reassess signal
  • Water retention / mild edema, joint discomfort — general GH-axis class effects
  • The DAC (long-acting) version specifically has more reports of allergic-type reactions in self-experimentation communities than Mod-GRF

Safety notes

Safety: Since no dedicated human trials of these modified compounds exist, dosing is community convention, not established pharmacology. The harm-reduction-minded corner of the community has shifted toward lower doses and the shorter-acting Mod-GRF version, based on accumulated adverse-reaction reports at higher doses and with the DAC version.
Community & reddit notes (anecdotal — not clinical evidence)

Almost always discussed and used paired with Ipamorelin or another GHRP, rather than alone. Widely seen as one of the 'gateway' GH-secretagogue combos, and a frequent subject of debate over optimal (generally lower-than-marketed) dosing.

Mixing compatibility

Pulled from a community-charted mixing-compatibility reference (anecdotal, clinic-use, and community-reported signals) — not a safety guarantee. Verify independently before combining anything.

Used together in wellness-clinic protocols

Anecdotally combined (outside clinic protocols)

Reported as a combination to avoid