Triptorelin
GnRH Agonist (long-acting)Also known as: Decapeptyl · Trelstar · D-Trp6-GnRH
A synthetic GnRH agonist that produces initial LH/FSH surge followed by pituitary desensitization, driving medical castration. Used in prostate cancer, endometriosis, & precocious puberty.
Typical Dose
3.75 mg IM monthly (prostate cancer); 0.1 mg daily SubQ (precocious puberty)
Route
Intramuscular or subcutaneous injection
Cycle
Ongoing (cancer); fixed term (puberty); clinical supervision required
Half-life
~3 hours (short-acting); depot formulations release over 1–3 months
Storage
As provided by manufacturer. Reconstitute per product instructions.
Overview
Triptorelin is a synthetic decapeptide GnRH analog with a D-tryptophan substitution at position 6, extending its half-life & pituitary receptor binding. Initial administration causes a surge in LH & FSH ('flare'), followed by downregulation of GnRH receptors & sustained suppression of gonadotropins & sex steroids — a paradoxical effect exploited for medical castration.
It is FDA approved for prostate cancer, precocious puberty, & endometriosis. In research peptide contexts, it is sometimes used for HPTA restart protocols after anabolic steroid use, though evidence for this application is limited.
Quick Start Guide
Triptorelin is a clinical drug administered by physicians. Not suitable for self-administration outside established medical protocols.
Research Indications
Prostate cancer (medical castration)
Most EffectiveFDA approved. Reduces testosterone to castrate levels within 2–4 weeks.
Endometriosis & uterine fibroids
Most EffectiveFDA approved. Suppresses estrogen, reducing endometrial implant growth.
Precocious puberty
Most EffectiveContinuous GnRH agonism suppresses premature gonadal activation in central precocious puberty.
Research Protocols
Prostate cancer (standard)
OngoingDose
3.75 mg
Frequency
Monthly IM depot injection
Route
IM
Side Effects & Safety
Common
- Hot flashes
- Sexual dysfunction (intended effect in cancer)
- Osteoporosis with long-term use
- Initial testosterone flare (first dose)
Uncommon
- Depression
- Injection site reactions
When to Stop
- Vertebral metastases with spinal cord compression (flare risk)
- Signs of allergic reaction
How to Reconstitute
Reconstitute per manufacturer microsphere depot instructions for clinical use.
Dosing math: Clinical product only. Self-administration is not appropriate for most indications.
Quality Indicators
Good — use as normal
- Manufacturer-stated appearance
Discard immediately
- Any deviation from manufacturer specification
What to Expect
Days 1–7 (flare)
Testosterone surges before receptor downregulation. Risk window for clinical conditions sensitive to androgen flare.
Week 2–4
Testosterone suppression begins. Castrate levels achieved by day 21–28 in most patients.
Community Insights
Self-reported. Reflects user experience, not clinical outcomes.
Research References
Triptorelin in advanced prostate cancer: a systematic review
Prostate Cancer & Prostatic Diseases · 2010
Systematic review confirming efficacy of triptorelin depot for androgen deprivation therapy in prostate cancer.
Verify what you have
Information on this page applies to pharmaceutical-grade peptides. Purity & identity of research-grade products vary. Certipep provides independent ESI-TOF-MS & HPLC analysis with a signed analytical report.
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