Triptorelin

What Is Triptorelin?

Triptorelin is a synthetic decapeptide GnRH (gonadotropin-releasing hormone) agonist that is 100x more potent than natural GnRH. It is FDA-approved as Trelstar for the palliative treatment of advanced prostate cancer. Unlike pulsatile GnRH (gonadorelin) which stimulates LH/FSH, continuous triptorelin administration paradoxically suppresses the HPG axis after an initial stimulation phase (flare).

This mechanism — initial stimulation followed by sustained suppression — makes triptorelin effective for conditions requiring hormonal suppression: prostate cancer (testosterone suppression), endometriosis, uterine fibroids, precocious puberty, and fertility treatment (controlled ovarian stimulation). It is also used in gender-affirming care as a puberty blocker.

Depot formulations (1-month, 3-month, 6-month) provide sustained drug release, enabling infrequent dosing. Triptorelin is one of several GnRH agonists (alongside leuprolide/Lupron and goserelin/Zoladex) used for hormonal manipulation.

What The Research Says

Clinical trials demonstrated triptorelin effectively reduces testosterone to castrate levels within 2-4 weeks (after initial flare) in prostate cancer patients. Long-term data shows sustained testosterone suppression with depot formulations. In fertility, triptorelin triggers ovulation for IVF egg retrieval.

Comparative studies show triptorelin is equivalent to other GnRH agonists for prostate cancer. In endometriosis, it reduces endometrial implant size and pain. As a puberty blocker, it reversibly suppresses pubertal development.

📚 Key Reference: PMID: 17194762 (triptorelin prostate cancer)

Common Uses

• Advanced prostate cancer (FDA-approved)
• Endometriosis (off-label)
• Uterine fibroids (off-label)
• Precocious puberty
• IVF trigger (off-label)
• Gender-affirming care (puberty suppression)
• Post-cycle therapy in anabolic steroid users (off-label)

Important Safety Information

Initial testosterone/estrogen flare can worsen symptoms in first 2-4 weeks. Hot flashes, decreased libido, erectile dysfunction, bone density loss with chronic use, mood changes, injection site reactions. Long-term use requires bone density monitoring. Cardiovascular risk may be increased. Consult your provider.

Questions To Ask Your Provider

1. What is the specific indication for triptorelin?
2. What is the expected duration of treatment?
3. How will bone density be monitored?
4. What hormonal monitoring will be performed?

Regulatory Status

FDA-approved as Trelstar (Allergan/AbbVie) for advanced prostate cancer. Off-label use in other indications is common and well-supported.