Mod GRF 1-29 (also called CJC-1295 without DAC) is the first 29 amino acids of GHRH with stabilizing modifications. Half-life ~30 minutes, versus 6-8 days for the DAC version.
Mechanism — Binds GHRH receptor on the pituitary to trigger natural-pulse GH release. The short half-life means the pulse decays — preserving the body's normal pulsatile pattern, which sustained GHRH elevation disrupts.
Use case — The natural-rhythm-preserving alternative to CJC-1295 with DAC. Stacked with a GHRP (ipamorelin, GHRP-2/6) for amplified pulse. Typical 100 mcg subcutaneous 1-3x daily.
Caveats — More injections per week. The short half-life is the point — don't run it as if it were the DAC version.