Triptorelin
Also known as: Trelstar, Decapeptyl, GnRH agonist
Triptorelin (also called Trelstar or Decapeptyl) is an FDA-approved depot GnRH agonist. Triptorelin is a GnRH agonist decapeptide with a D-tryptophan substitution at position six that increases receptor affinity and resists enzymatic degradation.
For research use only.
Key Facts
- CAS
- 57773-63-4
- Molecular Weight (MW)
- 1311.4 g/mol
- Half-life
- Depot: weeks to months
- FDA status
- Approved
- Administration Route
- Intramuscular
- Frequency
- Monthly to 24-week depot
- Last updated
- Aug 30, 2026
- Reviewed
- Aug 30, 2026
- Targets
- GnRH receptor
Research summary
FDA-approved depot GnRH agonist (Trelstar) for advanced prostate cancer. Causes flare then downregulation of LH/testosterone. WADA S2.
Peptide Library's Triptorelin profile summarises 5 cited studies listed in the Science section, the compound's regulatory status, and research-protocol parameters reported for it. It is a research reference, not medical advice.
Protocol
- Dosage Range
- Depot 3.75–22.5 mg IM on labeled intervals
- Frequency
- Monthly to 24-week depot
- Cycle
- Long-term ADT as prescribed
- Administration Route
- Intramuscular
- Reconstitution Guide
- —
- Injection Sites
- Gluteal
- Timing Notes
- Educational catalog only — not medical advice
Not yet checked against primary sources
These figures are compiled from earlier reference material. They have not been verified against FDA labelling, registered trials or published literature, no citation is attached to them, and none of them is a recommended dose. Triptorelin is queued for dosage evidence review.
Compare reported doses across the whole librarySequence & molecular data
| Molecular formula | C64H82N18O13 |
|---|---|
| Molecular weight | 1311.4 g/mol |
| CAS number | 57773-63-4 |
| Half-life | Depot: weeks to months |
| Appearance | Lyophilized powder for depot injection |
| Formulation | Lyophilized Powder |
| PubChem CID | 25074470 |
| FDA UNII | 9081Y98W2V |
| ChEMBL | CHEMBL1201334 |
| DrugBank | DB06825 |
Identifiers link to the public PubChem, FDA Substance Registration (UNII), ChEMBL and DrugBank records for the same entity.
Science
Mechanism of Action
Triptorelin is a GnRH agonist decapeptide with a D-tryptophan substitution at position six that increases receptor affinity and resists enzymatic degradation. Given as a depot it provides continuous rather than pulsatile receptor occupancy, which first stimulates and then desensitises pituitary gonadotrophs: luteinising and follicle-stimulating hormone rise transiently, then fall as the receptor is downregulated, and gonadal steroid production declines to castrate concentrations over roughly two to four weeks. The same initial flare seen with other GnRH agonists occurs, and formulations are available giving one, three or six months of suppression.
Origin
Synthetic decapeptide GnRH analog.
Targets
Studies
- A Phase 3, Open-Label, Single-Arm Trial of the Efficacy and Safety of Triptorelin 6-Month Formulation in Chinese Children with Central Precocious Puberty
- Adolescent Gender Dysphoria in Italy: Reflections on Triptorelin, Consent, and Care
- Triptorelin: The Need for Legal Protection Aimed at the Full Political and Social Integration of Gender Variant youth. A Comparison of Different Global realities
- GnRH agonist treatment before total laparoscopic hysterectomy for large uteri
- Spotlight on triptorelin in the treatment of premenopausal women with early-stage breast cancer
Regulatory & research status
Triptorelin is an FDA-approved product for specific labelled indications. Approval does not extend to the research contexts described on this page, and approved products are prescription medicines.
| FDA status | Approved |
|---|---|
| Availability | Prescription-Only |
| WADA (sport) | Banned in Sport |
| Library classification | FDA-Approved |
Benefits
Potential Side Effects
Side Effects
- Hot flashes
- Bone loss
- Tumor flare
- Injection-site reactions
Storage & stability
Lyophilized (freeze-dried) peptide powder is far more stable than the reconstituted solution. Keep sealed vials cold, dry and away from light; long-term storage is typically frozen, with short-term refrigeration for vials in use.
Once reconstituted in bacteriostatic water, keep the solution refrigerated, avoid repeated freeze–thaw cycles and agitation, and label the vial with the reconstitution date and concentration. Discard any solution that turns cloudy or shows particulates.
Degradation rates differ by sequence: peptides containing methionine, cysteine, asparagine or glutamine are more prone to oxidation and deamidation, so shelf life after reconstitution is compound-specific rather than universal.
Read the full guide: how to store peptides before and after reconstitution →
Source: Manning MC, Chou DK, Murphy BM, Payne RW, Katayama DS. Stability of protein pharmaceuticals: an update. Pharm Res. 2010;27(4):544–575. (PMID 20143256). General guidance for research handling; not product-specific instructions.
Triptorelin: frequently asked questions
What is Triptorelin?
FDA-approved depot GnRH agonist (Trelstar) for advanced prostate cancer. Causes flare then downregulation of LH/testosterone. WADA S2.
How does Triptorelin work?
Triptorelin is a GnRH agonist decapeptide with a D-tryptophan substitution at position six that increases receptor affinity and resists enzymatic degradation. Given as a depot it provides continuous rather than pulsatile receptor occupancy, which first stimulates and then desensitises pituitary gonadotrophs: luteinising and follicle-stimulating hormone rise transiently, then fall as the receptor is downregulated, and gonadal steroid production declines to castrate concentrations over roughly two to four weeks.
Is Triptorelin FDA approved?
Yes. Triptorelin is approved by the FDA, and approved products are prescription medicines. Approval is always for specific indications studied in clinical trials, so an approved status does not mean the compound is approved for every use it is discussed for. Research-chemical material sold under the same name is not the approved product.
What is the half-life of Triptorelin?
Reported half-life for Triptorelin is Depot: weeks to months. Half-life describes how long the compound persists in circulation, not how long any effect lasts, and published figures vary with route of administration, formulation and the population studied.
Is Triptorelin banned in sport?
Triptorelin is recorded here as prohibited in sport. Athletes subject to anti-doping rules should check the current WADA Prohibited List directly, since it is revised annually and classifications change.
What peptides are similar to Triptorelin?
Compounds most often compared with Triptorelin include Leuprolide, Goserelin, Nafarelin and Histrelin. They are grouped by shared mechanism or research area rather than by equivalence, and their regulatory status and evidence base differ.
References
- Trelstar labelExternal reference
- WADA Prohibited List 2026External reference
- A Phase 3, Open-Label, Single-Arm Trial of the Efficacy and Safety of Triptorelin 6-Month Formulation in Chinese Children with Central Precocious Puberty — Adv Ther, 2024External reference
- Adolescent Gender Dysphoria in Italy: Reflections on Triptorelin, Consent, and Care — Clin Ter, 2025External reference
- Triptorelin: The Need for Legal Protection Aimed at the Full Political and Social Integration of Gender Variant youth. A Comparison of Different Global realities — Clin Ter, 2025External reference
- GnRH agonist treatment before total laparoscopic hysterectomy for large uteri — J Am Assoc Gynecol Laparosc, 2003External reference
- Spotlight on triptorelin in the treatment of premenopausal women with early-stage breast cancer — Breast Cancer (Dove Med Press), 2018External reference
Related research, comparisons & guides
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Compiled by Peptide Library Editorial · Reviewed Aug 30, 2026 · Updated Aug 30, 2026 · Version 1
This Triptorelin profile is compiled from published literature (5 cited studies linked above), public regulatory records and chemical registries. It describes what research reports; it is not medical advice, and nothing here is a dosing recommendation for humans. Peptide Library does not sell peptides. Editorial policy · How profiles are compiled · Report an error
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