Degarelix
GnRH AntagonistAlso known as: Firmagon
A GnRH antagonist for prostate cancer that suppresses testosterone to castrate levels within 3 days without initial flare — faster than GnRH agonists.
Typical Dose
240 mg loading (2 x 120 mg); then 80 mg monthly
Route
Subcutaneous depot injection
Cycle
Monthly (ongoing for prostate cancer)
Half-life
~23–61 days (depot release)
Storage
Room temperature prior to reconstitution.
Overview
Degarelix is a synthetic decapeptide GnRH antagonist approved for advanced prostate cancer. Unlike leuprolide or triptorelin, it produces immediate testosterone suppression (no flare) & achieves castrate levels within 3 days. It is administered as a monthly SubQ depot.
Quick Start Guide
Physician-administered depot injection only. 240 mg loading dose followed by 80 mg monthly.
Research Indications
Advanced prostate cancer
Most EffectiveFDA approved. Achieves castrate testosterone in 3 days vs 28 days for GnRH agonists. No flare risk.
Research Protocols
Prostate cancer ADT
OngoingDose
240 mg load; 80 mg monthly
Frequency
Monthly SubQ depot
Route
SubQ (abdomen)
Side Effects & Safety
Common
- Injection site reactions (pain, erythema, swelling)
- Hot flashes
- Weight gain
Uncommon
- QT prolongation
- Osteoporosis
When to Stop
- QT prolongation
- Signs of allergic reaction
How to Reconstitute
Reconstitute per manufacturer instructions for depot preparation.
Dosing math: Clinical product — physician administration required.
Quality Indicators
Good — use as normal
- Per manufacturer
Discard immediately
- Per manufacturer
What to Expect
Day 1–3
Testosterone reaches castrate levels without flare. Faster than GnRH agonists.
Community Insights
Self-reported. Reflects user experience, not clinical outcomes.
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