What is Triptorelin?
Triptorelin is a GnRH agonist (not the native sequence) that, with continuous administration, causes downregulation of the reproductive axis. It is FDA-approved for prostate cancer, endometriosis, precocious puberty, and as part of gender-affirming care.
FDA-Approved Uses
Brand Names
- Trelstar (prostate cancer)
- Decapeptyl
- Gonapeptyl
Indications
- Advanced prostate cancer
- Endometriosis
- Uterine fibroids
- Central precocious puberty
- Gender-affirming hormone therapy
Mechanism
Agonist Effect Leading to Suppression
- Initial LH/FSH surge (flare)
- Continuous exposure
- Receptor downregulation
- Suppressed gonadotropins
- Reduced sex hormones
Why Suppression?
Unlike pulsatile GnRH which stimulates, continuous GnRH agonist exposure causes the pituitary to become desensitized, effectively shutting down the reproductive axis.
Clinical Use
Prostate Cancer:
- Reduces testosterone (chemical castration)
- Slows cancer growth
- Depot injections (monthly/quarterly)
Other Uses:
- Endometriosis pain relief
- Fibroid size reduction
- Puberty suppression
Summary
Triptorelin uses the paradox of continuous GnRH stimulation leading to suppression for therapeutic benefit.
Key Points:
- Classification: GnRH agonist
- FDA Status: Approved multiple indications
- Mechanism: Continuous = downregulation
- Uses: Prostate cancer, endometriosis, puberty