Triptorelin

Triptorelin is a potent, synthetic agonist analogue of Gonadotropin-Releasing Hormone (GnRH). It is a decapeptide that has been structurally modified from the native GnRH sequence, a change that makes it significantly more resistant to enzymatic degradation and increases its binding affinity to the GnRH receptor.

Its mechanism of action involves binding strongly to GnRH receptors in the anterior pituitary gland. When administered continuously, typically via a long-acting depot injection, Triptorelin causes an initial transient surge in Luteinizing Hormone (LH) and Follicle-Stimulating Hormone (FSH). However, this sustained, non-pulsatile stimulation leads to the desensitization and downregulation of the pituitary's GnRH receptors. This paradoxically suppresses the further release of LH and FSH, resulting in a profound reduction of sex hormone production (testosterone in men and estrogen in women) to castrate levels.

Due to its ability to induce this medical castration, Triptorelin is an FDA-approved medication used as a cornerstone of androgen deprivation therapy for the palliative treatment of advanced prostate cancer. It is also approved for the treatment of central precocious puberty in children.