# Triptorelin

> A GnRH-agonist decapeptide — the single D-tryptophan swap that turns native GnRH into a long-acting, axis-suppressing drug.

- Also known as: Trelstar, Decapeptyl, Triptorelin pamoate
- Class: Reproductive, Peptide Hormones
- FDA approved: Yes
- Canonical page: https://americanpeptide.com/catalog/triptorelin

## Overview

Triptorelin (Trelstar, Decapeptyl) is a synthetic GnRH agonist that differs from the native decapeptide by one change: a D-tryptophan at position 6. That single substitution resists the enzymatic cleavage that clears native GnRH within minutes, giving a potent, long-acting agonist. Like others in its class it first flares, then desensitizes the pituitary — suppressing LH, FSH, and the sex steroids downstream — and is delivered as sustained-release depots for prostate cancer, endometriosis, and central precocious puberty.

Triptorelin is the minimalist member of the GnRH-agonist class: where leuprolide makes two modifications to native GnRH, triptorelin makes one — replacing the glycine at position 6 with D-tryptophan. Native GnRH is cleaved at the Gly6–Leu7 bond within minutes; the D-amino acid at that position blocks the cleavage, converting a fleeting hormone into a depot drug that acts for weeks to months.

Functionally it behaves like the rest of its class. Continuous exposure produces a brief flare of LH and sex steroids, then downregulates the pituitary GnRH receptor and drives gonadotropins — and testosterone or estrogen — to castrate levels. It is used for advanced prostate cancer, endometriosis, and central precocious puberty, delivered almost entirely as long-acting pamoate depots.

Alongside gonadorelin (native GnRH) and leuprolide (the two-substitution analog), triptorelin rounds out the axis-suppression story this catalog tells: the same receptor, reached by progressively more stabilized analogs, each trading the native hormone’s pulsatile subtlety for durable, continuous suppression.

## Mechanism

GnRH-receptor agonism. After an initial gonadotropin flare, continuous exposure desensitizes the receptor and suppresses LH / FSH and gonadal steroid production.

## Chemistry

| Property | Value |
| --- | --- |
| Molecular formula | C64H82N18O13 |
| Molecular weight | 1311.4 Da |
| CAS number | 57773-63-4 |
| PubChem CID | [25074470](https://pubchem.ncbi.nlm.nih.gov/compound/25074470) |
| UniProt | [P01148](https://www.uniprot.org/uniprotkb/P01148) |

## Sequence

```
pGlu-His-Trp-Ser-Tyr-D-Trp-Leu-Arg-Pro-Gly-NH2
```

## Research areas

Studied in: Prostate cancer, Endometriosis, Central precocious puberty, Fertility (IVF).

Guides on this site:

- [Sexual & Reproductive Health](https://americanpeptide.com/research-areas/sexual-reproductive): Peptides studied across the HPG axis and CNS sexual-response pathways.

## Key research

- Single-substitution GnRH agonist — native GnRH with Gly6 → D-Trp, blocking the enzymatic cleavage that clears the native hormone.
- Flare-then-suppress — like the class, an initial gonadotropin flare gives way to receptor desensitization and sustained suppression of LH, FSH, and sex steroids.
- Approved uses — advanced prostate cancer, endometriosis, and central precocious puberty; also used in assisted-reproduction protocols.
- Depot delivery — formulated as long-acting pamoate injections because continuous exposure is what produces suppression.
- Class context — the one-change analog beside leuprolide (two changes) and gonadorelin (native GnRH).

## Storage, handling & synthesis

**Synthesis.** Triptorelin is the native GnRH decapeptide with a single D-tryptophan at position 6 and the C-terminal glycinamide retained. The two oxidation-sensitive tryptophans (positions 3 and 6) and the pyroglutamate terminus are the features to watch; assembly is otherwise a routine short solid-phase synthesis.

## FAQs

### What is triptorelin?

Triptorelin (Trelstar, Decapeptyl) is a long-acting GnRH agonist — native GnRH with a single D-tryptophan substitution at position 6 — used to suppress the reproductive hormone axis.

### How does it differ from leuprolide?

Both are GnRH agonists that suppress the axis by continuous stimulation. Triptorelin makes a single change to native GnRH (D-Trp6); leuprolide makes two (D-Leu6 plus a C-terminal ethylamide).

### What is it used for?

Advanced prostate cancer, endometriosis, and central precocious puberty, plus assisted-reproduction protocols — delivered as long-acting depot injections.

### Is triptorelin FDA-approved?

Yes — it is approved in the US (Trelstar) and widely elsewhere (Decapeptyl). This page is a research and educational reference, not medical advice.

## Latest research

Recent trials and publications mentioning Triptorelin, pulled automatically from ClinicalTrials.gov and PubMed (unfiltered search results, refreshed daily).

### Recent trials

- [Evaluating Hormone Therapy to Achieve Optimal Doses in Metastatic Prostate Cancer](https://clinicaltrials.gov/study/NCT07751133) — RECRUITING · PHASE3 · NCT07751133
- [Intranasal Nafarelin For Triggering Oocyte Maturation](https://clinicaltrials.gov/study/NCT06763926) — NOT_YET_RECRUITING · PHASE4 · NCT06763926
- [TRial on the Endocrine Activity of Neoadjuvant Degarelix](https://clinicaltrials.gov/study/NCT02005887) — COMPLETED · PHASE2 · NCT02005887
- [Evaluating the Addition of Adjuvant Chemotherapy to Ovarian Function Suppression Plus Endocrine Therapy in Premenopausal Patients With pN0-1, ER-Positive/HER2-Negative Breast Cancer and an Oncotype Recurrence Score Less Than or Equal to 25](https://clinicaltrials.gov/study/NCT05879926) — RECRUITING · PHASE3 · NCT05879926
- [Triptorelin for the Prevention of Ovarian Damage in Adolescents and Young Adults With Cancer](https://clinicaltrials.gov/study/NCT06513962) — RECRUITING · PHASE3 · NCT06513962
- [A Study of Adding Apalutamide to Radiotherapy and LHRH Agonist in High-Risk Patients With Hormone-Sensitive Prostate Cancer](https://clinicaltrials.gov/study/NCT04557059) — ACTIVE_NOT_RECRUITING · PHASE3 · NCT04557059

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Source: AmericanPeptide.com — https://americanpeptide.com/catalog/triptorelin
Data license: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Attribution: AmericanPeptide.com.
Research reference only — computational and educational content, not medical advice.