Triptorelin Reference

Plain English

What it is

Triptorelin, sold under the brand name Trelstar, is an FDA-approved prescription medicine for advanced prostate cancer. It is a GnRH agonist, a lab-made copy of a natural hormone signal that, after a short early rise, switches off the body's command to make testosterone. A clinician gives it as a shot into the muscle.

What people use it for

Doctors use it as palliative care for advanced prostate cancer, meaning it helps control the disease and ease symptoms rather than cure it, by lowering testosterone to very low levels that can slow the cancer's growth. It belongs to the same class as leuprolide (Lupron) and goserelin (Zoladex). There is no use for it outside cancer care, and only a clinician administers it.

What the science shows

This is a well-studied prescription drug supported by registration trials in advanced prostate cancer, where it reliably brought testosterone down to castration-level lows. The evidence that can be quoted here is for advanced prostate cancer. Outside the US it has other approved uses, but the US Trelstar label does not include them.

The catch

When treatment first starts, testosterone briefly rises, a flare that can temporarily worsen the cancer and may bring on bone pain, spinal cord compression, or trouble urinating, so an anti-androgen is often added early. The label also warns about serious allergic reactions and that this kind of hormone therapy can affect the heart's electrical timing (the QT interval). Off-label or self-administered use is unsafe and outside FDA approval.

Reference summary

Triptorelin is a long-acting synthetic decapeptide GnRH agonist. Like leuprolide and goserelin, sustained receptor occupancy produces pituitary downregulation and reversible medical castration after a transient initial gonadotropin surge. The Trelstar US label is anchored in advanced prostate cancer, with the 3.75 mg one-month, 11.25 mg three-month, and 22.5 mg six-month formulations established by registration trials demonstrating sustained castration-level testosterone. Outside the US, decades of European data also support GnRH-agonist use in pediatric central precocious puberty and adult endometriosis; the US Trelstar label does not include those uses.

Regulatory and posture

Categories

Reproductive, Hormonal

Aliases

Trelstar, GnRH agonist depot, Triptorelin pamoate, Decapeptyl, AY-25650

Evidence posture

human - Oncology drug. Prescription-only and clinician-administered as an intramuscular depot; off-label or self-administered use is not safe and is outside FDA approval. Tumor flare during the initial surge phase is a labeled risk in advanced prostate cancer; QT/QTc prolongation and cardiovascular risk are class-level androgen-deprivation concerns.

Regulatory status

FDA-approved prescription medication (Trelstar) for palliative treatment of advanced prostate cancer. Prescription-only and clinician-administered. Outside the US, triptorelin (Decapeptyl, Diphereline) carries additional approved indications including endometriosis, uterine fibroids, central precocious puberty, breast cancer, and male infertility from idiopathic oligozoospermia in several European markets; pepSmart only references the US Trelstar label.

Content review status

label verified

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