MOD-GRF (1-29) vs CJC-1295: the honest comparison
They are structurally the same 29-amino-acid sequence — the only difference is whether a DAC (drug-affinity complex) arm is attached for albumin binding. Mod-GRF 1-29 is the short-acting, pulsatile form; CJC-1295 with DAC is the long-acting, steady-state form. Pick based on whether you want GH pulses (Mod-GRF) or GH baseline elevation (CJC-DAC).
Side-by-side facts
| MOD-GRF (1-29) | CJC-1295 | |
|---|---|---|
| Class | GHRH analog (short-acting) | GHRH analog (growth-hormone-releasing hormone) |
| Half-life | Approximately 30 minutes | No-DAC: ~30 minutes. DAC version: ~6–8 days. |
| Typical dose | 100 mcg per injection, 1–3x daily (often pre-bed and/or post-workout) | 100 mcg, 1–3x daily (no-DAC); 1–2 mg weekly (DAC) |
| Category | Growth hormone axis | Growth hormone axis |
| FDA status | Not FDA approved. Research use only in the US. | Not FDA approved. Research use only. |
| Storage | Lyophilized: refrigerated. | Lyophilized refrigerated. |
What they have in common
Both are synthetic GHRH (1-29) analogs with tetrasubstituted stabilization. Both bind pituitary GHRH receptors and stimulate endogenous GH release. Both are typically paired with a GHRP (like Ipamorelin) for a full GH pulse. Both are research-only in the US.
When to pick MOD-GRF (1-29)
Pick Mod-GRF 1-29 (CJC-1295 without DAC) when you want pulsatile, physiological GH release without elevated baseline. Half-life ~30 minutes means each injection produces a brief sharp pulse and then clears. Typically dosed 100 mcg 1–3× daily — often pre-bed to ride the natural nocturnal GH surge. This is the preferred GHRH for users who want to preserve natural pulsatility and avoid receptor desensitization.
When to pick CJC-1295
Pick CJC-1295 with DAC when you want sustained GHRH tone with less frequent injections. The DAC arm binds albumin and extends half-life to ~8 days, so every-other-day or twice-weekly dosing produces an elevated baseline of GHRH signaling. Better for convenience; less physiological because it replaces the natural pulse pattern with continuous stimulation.
Can you stack them?
No — they are the same compound with and without the DAC modification. Running both produces no additional mechanism; pick one as your GHRH input and pair with a GHRP.
The two compounds
MOD-GRF (1-29)
MOD-GRF (1-29), also sold as CJC-1295 without DAC, is a stabilized analog of the first 29 amino acids of human GHRH. Commonly supplied as…
CJC-1295
CJC-1295 is a synthetic analog of growth-hormone-releasing hormone (GHRH). It stimulates the pituitary to release endogenous growth hormo…
Track either compound on iPhone
Peptide Protocol schedules doses, calculates reconstitution, and logs side effects for both — on iPhone, free to download.
See the app →Frequently asked questions
What is the main difference between MOD-GRF (1-29) and CJC-1295?
DAC. Mod-GRF 1-29 (CJC-1295 without DAC) has a ~30-minute half-life and produces GH pulses; CJC-1295 with DAC has a ~8-day half-life via albumin binding and produces sustained GHRH tone. Same underlying peptide, fundamentally different pharmacokinetics.
Can you stack MOD-GRF (1-29) and CJC-1295?
No — they are the same compound with and without the DAC modification. Running both produces no additional mechanism; pick one as your GHRH input and pair with a GHRP.
Which is better, MOD-GRF (1-29) or CJC-1295?
They are structurally the same 29-amino-acid sequence — the only difference is whether a DAC (drug-affinity complex) arm is attached for albumin binding. Mod-GRF 1-29 is the short-acting, pulsatile form; CJC-1295 with DAC is the long-acting, steady-state form. Pick based on whether you want GH pulses (Mod-GRF) or GH baseline elevation (CJC-DAC).
When should I pick MOD-GRF (1-29)?
Pick Mod-GRF 1-29 (CJC-1295 without DAC) when you want pulsatile, physiological GH release without elevated baseline. Half-life ~30 minutes means each injection produces a brief sharp pulse and then clears. Typically dosed 100 mcg 1–3× daily — often pre-bed to ride the natural nocturnal GH surge. This is the preferred GHRH for users who want to preserve natural pulsatility and avoid receptor desensitization.
When should I pick CJC-1295?
Pick CJC-1295 with DAC when you want sustained GHRH tone with less frequent injections. The DAC arm binds albumin and extends half-life to ~8 days, so every-other-day or twice-weekly dosing produces an elevated baseline of GHRH signaling. Better for convenience; less physiological because it replaces the natural pulse pattern with continuous stimulation.
Are MOD-GRF (1-29) and CJC-1295 FDA approved?
MOD-GRF (1-29): Not FDA approved. Research use only in the US. — CJC-1295: Not FDA approved. Research use only.
Educational use only. Peptide Protocol is an informational tool. Nothing on this page constitutes medical advice. Many peptides are prescription-only or restricted in your jurisdiction. Always consult a licensed healthcare professional before injecting any compound.