Triptorelin (D-Trp6-GnRH; also D-Trp6-LHRH) is a synthetic decapeptide GnRH analog in which the natural L-glycine at position 6 is replaced with D-tryptophan. This single D-amino acid substitution produces two critical pharmacological differences from native GnRH or Gonadorelin: (1) resistance to proteolytic cleavage by endopeptidases that rapidly degrade the natural L-amino acid chain, resulting in a substantially extended half-life; and (2) enhanced GnRH receptor (GnRHR) binding affinity approximately 100-fold greater than endogenous GnRH, owing to a complementary fit with the GnRHR binding pocket. Triptorelin acts as a GnRHR agonist on pituitary gonadotroph cells. Binding activates the Gq-coupled receptor, triggering PLC-mediated hydrolysis of PIP2 into IP3 and DAG, calcium mobilization from the endoplasmic reticulum, PKC activation, and downstream transcriptional upregulation of LHβ and FSHβ gonadotropin subunit genes. The result is robust LH and FSH secretion — an exaggerated res
Triptorelin: High-Affinity GnRH Analog Research Guide
Triptorelin is a synthetic GnRH decapeptide analog with a D-Trp6 substitution that confers ~100-fold greater GnRHR binding affinity and proteolytic resistance versus native GnRH. Researchers use it to study receptor occupancy, gonadotropin pulse dynamics, and HPG axis pharmacology.