Source comparison
Mechanism of Action — Upstream vs Downstream Pathways
CJC-1295 no DAC (modified GRF 1-29) is a 29-amino acid analog of growth hormone-releasing hormone with four amino acid substitutions that extend its biological half-life from under 7 minutes (native GHRH) to approximately 30 minutes to 2 hours post-subcutaneou
This comparison does not assign a generated winner or score.
- CJC-1295 no DAC (modified GRF 1-29) is a 29-amino acid analog of growth hormone-releasing hormone with four amino acid substitutions that extend its biological half-life from under 7 minutes (native GHRH) to approximately 30 minutes to 2 hours post-subcutaneous injection. It binds to GHRH receptors (GHRHR) on somatotroph cells in the anterior pituitary gland, activating adenylyl cyclase and increasing intracellular cyclic AMP (cAMP) levels. This triggers calcium influx and stimulates the release of stored growth hormone granules into circulation. The GH pulse generated by CJC-1295 no DAC follows physiological feedback regulation: circulating GH binds to hepatic GH receptors, stimulating insulin-like growth factor-1 (IGF-1) production via JAK-STAT signaling pathways, and elevated IGF-1 then feeds back negatively on the hypothalamus and pituitary to suppress further GH release. This preserves the body's natural regulatory architecture.
- IGF-1 LR3 (Long R3 Insulin-Like Growth Factor-I) is a recombinant 83-amino acid analog of human IGF-1 with an N-terminal 13-amino acid extension and a glutamic acid substitution at position 3. These modifications reduce its binding affinity to IGF-binding proteins (IGFBPs). Particularly IGFBP-3, which normally sequesters over 90% of circulating IGF-1 in a biologically inactive ternary complex with the acid-labile subunit (ALS). By evading IGFBP sequestration, IGF-1 LR3 remains in free, bioactive form for 20–30 hours and binds directly to IGF-1 receptors (IGF1R) on target tissues including skeletal muscle, adipocytes, chondrocytes, and fibroblasts. IGF1R is a receptor tyrosine kinase. Ligand binding triggers autophosphorylation and activation of PI3K-Akt and MAPK-ERK pathways, driving protein synthesis, glucose uptake, glycogen synthesis, and inhibition of apoptosis. Because IGF-1 LR3 bypasses the hypothalamic-pituitary axis entirely, it does not trigger compensatory feedback suppressio
- Our experience with research-grade peptide synthesis shows this upstream-versus-downstream distinction determines practical research outcomes more than dose or frequency. If your experimental model requires intact neuroendocrine feedback, CJC-1295 no DAC is the correct choice. If you're studying direct receptor agonism at target tissues independent of pituitary function, IGF-1 LR3 is appropriate.