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Catalog/Triptorelin

Triptorelin

Also known as Trelstar · Decapeptyl · Triptorelin pamoate

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

Research refreshed

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.

Background

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.

Key research findings

  • 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).

How Triptorelin is made

Behind every vial of Triptorelin is the same exacting pipeline every research peptide runs — but the chemistry plays out differently for this molecule. Here is how Triptorelin, specifically, is brought into being.

  1. On paper first

    On paper, Triptorelin is C64H82N18O13 — about 1,311.4 daltons of precisely arranged atoms. Before a single bond is made, the target sequence, salt form, and purity threshold are written down as the contract the finished material must meet.

  2. Built residue by residue

    Triptorelin's chain is short but unusual — it carries D-amino acids that help it resist enzymatic breakdown, but demand specialized, costlier building blocks and careful coupling on the synthesizer. Its C-terminus is amidated rather than left as a free acid — a defined modification the synthesis has to deliver, not an afterthought.

  3. Purity is won here

    The crude mixture — Triptorelin plus its deletions and side products — is then separated on preparative HPLC, and where the cut is taken decides the difference between a genuinely pure peptide and a barely-passable one.

  4. Proven, then protected

    A real batch of Triptorelin proves itself: identity confirmed by mass spectrometry against its ~1,311.4 Da, purity read directly off an analytical HPLC trace, water and counterion content measured. That batch-specific certificate of analysis is the only honest way to know what is actually in a vial of Triptorelin — and a short, cold, accountable chain of custody is how that purity survives the trip to your bench.

Walk the full synthesis pipeline

Handling, storage & why purity is hard

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.

Don't judge a vial by its cake. A fluffy, good-looking lyophilized powder reflects bulking agents and freeze-drying parameters — not purity. Insist on a batch-specific certificate of analysis.

How peptides are made — the full pipeline

Research areas

  • Prostate cancer
  • Endometriosis
  • Central precocious puberty
  • Fertility (IVF)

Research-area guides

Latest research

Recent clinical trials and publications mentioning Triptorelin, pulled automatically from ClinicalTrials.gov and PubMed and refreshed daily. Listings are unfiltered search results, not curated endorsements.

Frequently asked questions

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.

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Dosing protocols, mechanism, comparisons, and the latest trials — citation-backed answers grounded in PubMed, PubChem, and ClinicalTrials.gov.