TesamorelinEnhanced GHRH Analog (Egrifta / TH9507) — Research Reference by QSC Peptides

Tesamorelin (TH9507 / Egrifta) is a synthetic GHRH analog incorporating a trans-3-hexenoic acid group at the N-terminus of the full 44-amino-acid GHRH sequence. This modification shields the Tyr1-Ala2 dipeptide from DPP-IV cleavage — the primary plasma degradation pathway for native GHRH — significantly extending the biological half-life (~90 min vs ~5 min for native GHRH) while preserving full GHRHR binding affinity.

Tesamorelin binds the GHRHR as a full agonist, activating Gs-protein → adenylyl cyclase → cAMP → PKA → CREB phosphorylation → GH gene transcription and pulsatile GH secretion from pituitary somatotrophs.

Stability Advantage Over Sermorelin and CJC-1295 (No DAC)

Native GHRH and Sermorelin are cleaved by DPP-IV within minutes. CJC-1295 No DAC achieves ~30 min t½ through amino acid substitutions. Tesamorelin's N-terminal modification provides comparable or superior DPP-IV resistance to CJC-1295 No DAC, giving it a longer active window while retaining the full 44-aa GHRH sequence for maximal receptor engagement.